Theobromine
Studies and references cited across this article, graded by evidence strength.
Inconclusive means the cited source neither confirms nor refutes the claim — a lower-confidence badge, not an error.
Data points an editor reviewed and accepted for publication.
Value Provenance
Dosing
oraltrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Threshold | 50 mg | 50 mg | low |
| Low | 100–200 mg | 100–200 mg | low |
| Common | 200–400 mg | 200–400 mg | low |
| Strong | 500–700 mg | 500–700 mg | low |
| Heavy | 850+ mg | 850+ mg | low |
| Editorial | Threshold (~50 mg): dietary chocolate doses produce no measurable isolated effects — inferred from absence of documented effects below 100 mg. Light (100–200 mg): supplement literature lower range, no controlled data — confidence low. Common (200–400 mg): supplement literature moderate range, no controlled data — confidence low. Strong (500–700 mg): 500 mg/day produced metabolic effects (Smolders 2018); 700 mg produced decreased calmness (Mitchell 2011) — confidence medium for this tier specifically. Heavy (850 mg): EFSA review documents increased adverse events at 850 mg/day — confidence medium. Overall confidence set to low because threshold/light/common tiers lack dose-ranging study support. Bioavailability: ~100% from aqueous solution, ~80% from chocolate matrix (Shively 1985). NOTE: These dose tiers reflect physiological/metabolic effect thresholds rather than subjective psychoactive intensity — theobromine is barely psychoactive as an isolated compound. | ||
ReasoningReasoningThreshold (~50 mg): dietary chocolate doses produce no measurable isolated effects — inferred from absence of documented effects below 100 mg. Light (100–200 mg): supplement literature lower range, no controlled data — confidence low. Common (200–400 mg): supplement literature moderate range, no controlled data — confidence low. Strong (500–700 mg): 500 mg/day produced metabolic effects (Smolders 2018); 700 mg produced decreased calmness (Mitchell 2011) — confidence medium for this tier specifically. Heavy (850 mg): EFSA review documents increased adverse events at 850 mg/day — confidence medium. Overall confidence set to low because threshold/light/common tiers lack dose-ranging study support. Bioavailability: ~100% from aqueous solution, ~80% from chocolate matrix (Shively 1985). NOTE: These dose tiers reflect physiological/metabolic effect thresholds rather than subjective psychoactive intensity — theobromine is barely psychoactive as an isolated compound. Evidence basis: community_consensus_small | |||
Duration
oral
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Onsettrace | 30–60 minutes | 30–60 minutes | low |
| Editorial | No controlled studies measuring onset of theobromine's subjective effects exist. Inferred from pharmacokinetic data: near-complete oral bioavailability with Tmax not reported (Shively 1985). Work-notes suggest 30–60 min based on typical oral methylxanthine absorption kinetics. | ||
ReasoningReasoningNo controlled studies measuring onset of theobromine's subjective effects exist. Inferred from pharmacokinetic data: near-complete oral bioavailability with Tmax not reported (Shively 1985). Work-notes suggest 30–60 min based on typical oral methylxanthine absorption kinetics. Evidence basis: structural_analogy | |||
| Peaktrace | 1–3 hours | 1–3 hours | low |
| Editorial | Inferred from Mitchell 2011: blood pressure lowering at 1h post-dose, decreased calmness at 3h post-dose, suggesting peak pharmacological effects in the 1–3h window. No direct measurement of subjective peak duration exists. Work-notes recommend this range. | ||
ReasoningReasoningInferred from Mitchell 2011: blood pressure lowering at 1h post-dose, decreased calmness at 3h post-dose, suggesting peak pharmacological effects in the 1–3h window. No direct measurement of subjective peak duration exists. Work-notes recommend this range. Evidence basis: structural_analogy | |||
| Totaltrace | 6–10 hours | 6–10 hours | low |
| Editorial | Inferred from elimination half-life of ~10 hours (Shively 1985). Total subjective duration is difficult to define for a compound whose effects barely exceed threshold. Range of 6–10h reflects the pharmacokinetic window during which plasma concentrations remain above estimated effect thresholds. Work-notes specify this range. Note: this is pharmacokinetic inference, not measured subjective duration. | ||
ReasoningReasoningInferred from elimination half-life of ~10 hours (Shively 1985). Total subjective duration is difficult to define for a compound whose effects barely exceed threshold. Range of 6–10h reflects the pharmacokinetic window during which plasma concentrations remain above estimated effect thresholds. Work-notes specify this range. Note: this is pharmacokinetic inference, not measured subjective duration. Evidence basis: structural_analogy | |||
| After effectstrace | 0–2 hours | 0–2 hours | low |
| Editorial | No data on aftereffects. Work-notes specify 'aftereffects minimal.' Given the gentle, flat experiential arc and absence of documented rebound effects, aftereffects are expected to be negligible to absent. Range of 0–2h proposed conservatively. | ||
ReasoningReasoningNo data on aftereffects. Work-notes specify 'aftereffects minimal.' Given the gentle, flat experiential arc and absence of documented rebound effects, aftereffects are expected to be negligible to absent. Range of 0–2h proposed conservatively. Evidence basis: structural_analogy | |||
Safety
Toxicity Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Acute | negligible | negligible | high |
| Chronic | low | low | high |
| Organs Affected | cardiovascular, metabolic | cardiovascular, metabolic | high |
| Editorial | EFSA systematic safety review, multiple RCTs, and animal LD50 data collectively establish a wide safety margin at dietary exposures. No human fatalities documented. Animal NOAEL ~50 mg/kg/day. Acute toxicity is negligible given GRAS status and absence of documented harm at typical doses. Chronic toxicity is low based on metabolic effects (glucose/insulin) at 500 mg/day sustained dosing — minor, reversible physiological effects without documented organ damage. | ||
ReasoningReasoningEFSA systematic safety review, multiple RCTs, and animal LD50 data collectively establish a wide safety margin at dietary exposures. No human fatalities documented. Animal NOAEL ~50 mg/kg/day. Acute toxicity is negligible given GRAS status and absence of documented harm at typical doses. Chronic toxicity is low based on metabolic effects (glucose/insulin) at 500 mg/day sustained dosing — minor, reversible physiological effects without documented organ damage. Evidence basis: controlled_human_study | |||
Dependence Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Physical | none | none | low |
| Psychological | negligible | negligible | low |
| Compulsive Redosing | negligible | negligible | low |
| Dose Escalation | negligible | negligible | low |
| Editorial | No published studies on theobromine-specific dependence or withdrawal exist. Assessment is class inference from caffeine (which has mild dependence liability), discounted substantially due to theobromine's much weaker CNS effects and negligible A2A receptor engagement. Work-notes specify confidence=low and structural_analogy basis. | ||
ReasoningReasoningNo published studies on theobromine-specific dependence or withdrawal exist. Assessment is class inference from caffeine (which has mild dependence liability), discounted substantially due to theobromine's much weaker CNS effects and negligible A2A receptor engagement. Work-notes specify confidence=low and structural_analogy basis. Evidence basis: structural_analogy | |||
Withdrawal Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Severity | none | none | low |
| Symptoms | — | — | low |
| Fatal | No | No | low |
| Medical Supervision | Not required | Not required | low |
| Editorial | No published studies have examined theobromine-specific withdrawal. Given the absence of measurable physical dependence and negligible psychological dependence, no withdrawal syndrome is expected. Class inference from caffeine (which produces mild withdrawal — headache, fatigue) is heavily discounted due to theobromine's much weaker CNS activity. | ||
ReasoningReasoningNo published studies have examined theobromine-specific withdrawal. Given the absence of measurable physical dependence and negligible psychological dependence, no withdrawal syndrome is expected. Class inference from caffeine (which produces mild withdrawal — headache, fatigue) is heavily discounted due to theobromine's much weaker CNS activity. Evidence basis: structural_analogy | |||
Tolerance Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Buildup | none | none | low |
| Half-life | — | — | low |
| Full Reset | — | — | low |
| Cross-tolerances | caffeine | caffeine | low |
| Editorial | Shively 1985 directly demonstrated absence of pharmacokinetic tolerance. Pharmacodynamic tolerance is entirely unstudied — the 'none' buildup rating reflects PK data only. Cross-tolerance with caffeine is inferred from shared adenosine antagonism mechanism (structural analogy). Work-notes specify confidence=low for all tolerance parameters. | ||
ReasoningReasoningShively 1985 directly demonstrated absence of pharmacokinetic tolerance. Pharmacodynamic tolerance is entirely unstudied — the 'none' buildup rating reflects PK data only. Cross-tolerance with caffeine is inferred from shared adenosine antagonism mechanism (structural analogy). Work-notes specify confidence=low for all tolerance parameters. Evidence basis: structural_analogy | |||
Effects & Profile
Contraindications
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| metabolic Impaired glucose tolerance / diabetestrace | relative | relative | medium |
| Editorial | Direct RCT evidence from Smolders 2018 showing unfavorable glucose/insulin responses at 500 mg/day. The most clinically relevant safety signal in humans from controlled data. | ||
ReasoningReasoningDirect RCT evidence from Smolders 2018 showing unfavorable glucose/insulin responses at 500 mg/day. The most clinically relevant safety signal in humans from controlled data. | |||
| pregnancy breastfeeding Pregnancytrace | relative | relative | low |
| Editorial | Animal teratogenicity data at high doses (Tarka 1986, York 1986) combined with absence of human data. Class inference from caffeine pregnancy guidance. No human teratogenicity data exists — precautionary principle applies. | ||
ReasoningReasoningAnimal teratogenicity data at high doses (Tarka 1986, York 1986) combined with absence of human data. Class inference from caffeine pregnancy guidance. No human teratogenicity data exists — precautionary principle applies. | |||
| cardiovascular Pre-existing tachyarrhythmiastrace | relative | relative | low |
| Editorial | Single case report of sinus tachycardia with extreme chocolate consumption (PMID 41523427). Mechanism consistent with methylxanthine class pharmacology. Risk is relevant only at extreme supplement doses, not dietary consumption. | ||
ReasoningReasoningSingle case report of sinus tachycardia with extreme chocolate consumption (PMID 41523427). Mechanism consistent with methylxanthine class pharmacology. Risk is relevant only at extreme supplement doses, not dietary consumption. | |||
| other Concurrent CYP1A2 inhibitor therapytrace | relative | relative | medium |
| Editorial | CYP1A2 involvement in theobromine metabolism documented by Gates & Miners 1999. No clinical interaction studies exist — interaction is inferred from enzyme involvement. Safety-critical gap flagged in work-notes. | ||
ReasoningReasoningCYP1A2 involvement in theobromine metabolism documented by Gates & Miners 1999. No clinical interaction studies exist — interaction is inferred from enzyme involvement. Safety-critical gap flagged in work-notes. | |||
Timeline Phases
oral
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Onsettrace | 1800–3600 sec(i=0.20) | 1800–3600 sec(i=0.20) | low |
| Editorial | No controlled studies measuring onset, peak, or offset of theobromine's subjective effects exist. Timeline inferred from pharmacokinetic data: ~10h elimination half-life (Shively 1985), blood pressure lowering at 1h and decreased calmness at 3h post-dose (Mitchell 2011). Work-notes specify onset 30–60 min, peak 1–3h, total 6–10h, and recommend minimal phase count (onset/peak/resolution only). Come-up, plateau, and afterglow phases are not meaningfully distinct for this substance. | ||
ReasoningReasoningNo controlled studies measuring onset, peak, or offset of theobromine's subjective effects exist. Timeline inferred from pharmacokinetic data: ~10h elimination half-life (Shively 1985), blood pressure lowering at 1h and decreased calmness at 3h post-dose (Mitchell 2011). Work-notes specify onset 30–60 min, peak 1–3h, total 6–10h, and recommend minimal phase count (onset/peak/resolution only). Come-up, plateau, and afterglow phases are not meaningfully distinct for this substance. Evidence basis: structural_analogy | |||
| Peaktrace | 5400–10800 sec(i=0.50) | 5400–10800 sec(i=0.50) | low |
| Editorial | No controlled studies measuring onset, peak, or offset of theobromine's subjective effects exist. Timeline inferred from pharmacokinetic data: ~10h elimination half-life (Shively 1985), blood pressure lowering at 1h and decreased calmness at 3h post-dose (Mitchell 2011). Work-notes specify onset 30–60 min, peak 1–3h, total 6–10h, and recommend minimal phase count (onset/peak/resolution only). Come-up, plateau, and afterglow phases are not meaningfully distinct for this substance. | ||
ReasoningReasoningNo controlled studies measuring onset, peak, or offset of theobromine's subjective effects exist. Timeline inferred from pharmacokinetic data: ~10h elimination half-life (Shively 1985), blood pressure lowering at 1h and decreased calmness at 3h post-dose (Mitchell 2011). Work-notes specify onset 30–60 min, peak 1–3h, total 6–10h, and recommend minimal phase count (onset/peak/resolution only). Come-up, plateau, and afterglow phases are not meaningfully distinct for this substance. Evidence basis: structural_analogy | |||
| Resolutiontrace | 10800–25200 sec(i=0.20) | 10800–25200 sec(i=0.20) | low |
| Editorial | No controlled studies measuring onset, peak, or offset of theobromine's subjective effects exist. Timeline inferred from pharmacokinetic data: ~10h elimination half-life (Shively 1985), blood pressure lowering at 1h and decreased calmness at 3h post-dose (Mitchell 2011). Work-notes specify onset 30–60 min, peak 1–3h, total 6–10h, and recommend minimal phase count (onset/peak/resolution only). Come-up, plateau, and afterglow phases are not meaningfully distinct for this substance. | ||
ReasoningReasoningNo controlled studies measuring onset, peak, or offset of theobromine's subjective effects exist. Timeline inferred from pharmacokinetic data: ~10h elimination half-life (Shively 1985), blood pressure lowering at 1h and decreased calmness at 3h post-dose (Mitchell 2011). Work-notes specify onset 30–60 min, peak 1–3h, total 6–10h, and recommend minimal phase count (onset/peak/resolution only). Come-up, plateau, and afterglow phases are not meaningfully distinct for this substance. Evidence basis: structural_analogy | |||
Dose Tier Summaries
Dietary chocolate doses in the range of 30–50 mg produce no measurable isolated psychoactive or physiological effects distinguishable from placebo. Theobromine is pharmacologically present at this level but falls below any demonstrated effect threshold. Physical effects are absent at this range. The compound undergoes near-complete oral absorption and begins hepatic metabolism, but plasma concentrations remain too low to produce detectable adenosine receptor antagonism or phosphodiesterase inhibition in any target tissue. A standard 40 g serving of dark chocolate delivers approximately 33–46 mg of theobromine — squarely within this range. No sleep disruption, diuresis, or cardiovascular effects are expected.
No dose-ranging study exists for theobromine's threshold. Value inferred from dietary chocolate content data (Ramli 2000: 0.82–1.14 mg/g dark chocolate) and absence of any documented effects below 100 mg in isolation. Work-notes specify this tier as class inference.
ReasoningReasoning
No dose-ranging study exists for theobromine's threshold. Value inferred from dietary chocolate content data (Ramli 2000: 0.82–1.14 mg/g dark chocolate) and absence of any documented effects below 100 mg in isolation. Work-notes specify this tier as class inference.
Evidence basis: structural_analogy
Supplement-range doses of 100–200 mg may produce mild peripheral methylxanthine effects. Slight diuresis (increased urination) and mild bronchodilation are the most plausible effects at this range, consistent with PDE inhibition and adenosine A1 receptor antagonism. No documented subjective CNS effects — stimulation, wakefulness, or mood changes — have been demonstrated at this dose range for theobromine in isolation. Any central effects would be substantially weaker than those produced by equivalent caffeine doses. This range corresponds to consumption of approximately 100–250 g of dark chocolate or commercially available theobromine supplements at their lowest recommended doses.
No controlled human studies at this dose range for isolated theobromine. Values inferred from supplement literature ranges and class pharmacology of methylxanthines, heavily discounted from caffeine. Work-notes flag this tier as unsupported by direct evidence.
ReasoningReasoning
No controlled human studies at this dose range for isolated theobromine. Values inferred from supplement literature ranges and class pharmacology of methylxanthines, heavily discounted from caffeine. Work-notes flag this tier as unsupported by direct evidence.
Evidence basis: structural_analogy
Moderate supplement doses of 200–400 mg produce peripheral methylxanthine effects including mild vasodilation, increased urination, and possible mild antitussive activity. Theobromine's antitussive mechanism — direct peripheral inhibition of sensory nerve activation — may begin to be functionally relevant at the upper end of this range. Subjective psychoactive effects remain minimal to absent. No controlled study has demonstrated measurable stimulation, alertness enhancement, or mood changes at doses below 500 mg. The experiential character at this tier is defined by what is not felt rather than what is. This range is achievable only through deliberate supplementation with pure theobromine — dietary chocolate consumption alone is unlikely to reach 200 mg in a single sitting.
No controlled human dose-response data at 200–400 mg for isolated theobromine. Range inferred from supplement literature and positioned below the 500 mg threshold at which metabolic effects were demonstrated (Smolders 2018). Work-notes flag as unsupported by dose-ranging study.
ReasoningReasoning
No controlled human dose-response data at 200–400 mg for isolated theobromine. Range inferred from supplement literature and positioned below the 500 mg threshold at which metabolic effects were demonstrated (Smolders 2018). Work-notes flag as unsupported by dose-ranging study.
Evidence basis: community_consensus_small
At 500–700 mg, controlled studies document the first measurable effects from theobromine in isolation. At 700 mg, Mitchell et al. (2011) found decreased self-reported calmness and peripheral blood pressure lowering — the only controlled demonstration of theobromine's subjective psychoactive effects. No measurable alertness gain or psychomotor enhancement accompanied these changes. Physically, this range produces detectable vasodilation and blood pressure reduction. At 500 mg/day sustained for 4 weeks, unfavorable postprandial glucose and insulin responses were documented (Smolders 2018), representing the most clinically significant metabolic finding. This tier marks the first detectable subjective shift — a mild reduction in calmness without corresponding stimulation. The experience is subtle and may go unnoticed without attentive self-monitoring.
Strong/heavy tiers are supported by RCT data: Mitchell 2011 (700 mg, decreased calmness, BP lowering) and Smolders 2018 (500 mg/day, glucose/insulin effects). Work-notes assign medium confidence to these tiers.
ReasoningReasoning
Strong/heavy tiers are supported by RCT data: Mitchell 2011 (700 mg, decreased calmness, BP lowering) and Smolders 2018 (500 mg/day, glucose/insulin effects). Work-notes assign medium confidence to these tiers.
Evidence basis: controlled_human_study
At 850–1000 mg, the EFSA safety review found that adverse event rates increase significantly. This range approaches the upper boundary of human tolerability for single or sustained daily doses. The specific nature of adverse events at these doses is incompletely described in published literature. Cardiovascular effects become more likely — potential for tachycardia with sustained high dosing, particularly in combination with other methylxanthine sources (caffeine from coffee or tea). At 850 mg single acute dose, downregulation of glucose metabolism genes was observed in duodenal biopsies. This dose range is achievable only through deliberate supplementation with purified theobromine. No dietary chocolate consumption pattern would reliably deliver 850+ mg of theobromine in a single serving. Individuals with cardiovascular conditions, diabetes, or impaired glucose tolerance should avoid this range.
EFSA (2017) safety review documents increased adverse events at 850 mg/day and highest adverse event rate at 1000 mg/day. Supported by duodenal biopsy data at 850 mg. Work-notes assign medium confidence based on regulatory review data.
ReasoningReasoning
EFSA (2017) safety review documents increased adverse events at 850 mg/day and highest adverse event rate at 1000 mg/day. Supported by duodenal biopsy data at 850 mg. Work-notes assign medium confidence based on regulatory review data.
Evidence basis: systematic_review
History
backfill Jun 4, 2026
Historical versions do not record which reviewer approved them; editorial accountability is recorded per value in the database and in the publication ledger going forward.
Sources
- [1]moderateImpact of Coffee and Cacao Purine Metabolites on Neuroplasticity and Neurodegenerative DiseaseCamandola S, Plick N, Mattson MP · 2019 · Neurochemical Research
- [2]moderateCocoa phytochemicals: recent advances in molecular mechanisms on healthKim J, Kim J, Shim J, Lee CY, Lee KW, Lee HJ · 2014 · Critical Reviews in Food Science and Nutrition
- [3]moderateHigh levels of methylxanthines in chocolate do not alter theobromine dispositionShively CA, Tarka SM, Arnaud MJ, Dvorchik BH, Passananti GT, Vesell ES · 1985 · Clinical Pharmacology and Therapeuticspubmed 397900310 claims checked9 verified1 inconclusive
- [4]weak
- [5]strongTheobromine inhibits sensory nerve activation and coughUsmani OS, Belvisi MG, Patel HJ, Crispino N, Birrell MA, Korbonits M, Korbonits D, Barnes PJ · 2005 · FASEB Journalpubmed 155485875 claims checked3 verified2 partial
- [6]strongSub-Chronic Consumption of Dark Chocolate Enhances Cognitive Function and Releases Nerve Growth Factors: A Parallel-Group Randomized TrialSumiyoshi E, Matsuzaki K, Sugimoto N, Tanabe Y, Hara T, Katakura M, Miyamoto M, Mishima S, Shido O · 2019 · Nutrients
- [7]moderateTheobromine Targets Adenosine Receptors to Control Hippocampal Neuronal Function and DamageValada P, Alcada-Morais S, Cunha RA, Lopes JP · 2022 · International Journal of Molecular Sciences
- [8]moderateThe toxicology of cocoa and methylxanthines: a review of the literatureTarka SM · 1982 · Critical Reviews in Toxicologypubmed 67656107 claims checked7 inconclusive
- [9]strongDifferential contributions of theobromine and caffeine on mood, psychomotor performance and blood pressureMitchell ES, Slettenaar M, vd Meer N, Transler C, Jans L, Quadt F, Berry M · 2011 · Physiology & Behavior
- [10]strongMethylxanthines are the psycho-pharmacologically active constituents of chocolateSmit HJ, Gaffan EA, Rogers PJ · 2004 · Psychopharmacologypubmed 155492764 claims checked4 inconclusive
- [11]weakEFSA Scientific Opinion: Flavouring Group Evaluation 49, Revision 1 - xanthine alkaloids (includes theobromine)2017linkno claims checked
- [12]weak
- [13]moderateCocoa intake, blood pressure, and cardiovascular mortality: the Zutphen Elderly StudyBuijsse B, Feskens EJM, Kok FJ, Kromhout D · 2006 · Archives of Internal Medicine
- [14]strongEffect of cocoa and theobromine consumption on serum HDL-cholesterol concentrations: a randomized controlled trialNeufingerl N, Zebregs YE, Schuring EA, Trautwein EA · 2013 · American Journal of Clinical Nutrition
- [15]strongTheobromine supplementation in combination with a low-calorie diet improves cardiovascular risk factors in overweight and obese subjects with metabolic syndrome: a randomized controlled trialSharifi-Zahabi E, Rezvani N, Hajizadeh-Sharafabad F, Hosseini-Baharanchi FS, Shidfar F, Rahimi M · 2023 · Food & Function
- [16]strongEffects of high flavanol dark chocolate on cardiovascular function and platelet aggregationRull G, Mohd-Zain ZN, Shiel J, Lundberg MH, Collier DJ, Johnston A, Warner TD, Corder R · 2015 · Vascular Pharmacology
- [17]weakTheobromine - Coffee, Tea, Mate, Methylxanthines and Methylglyoxal - NCBI Bookshelf NBK5070322018linkno claims checked
- [18]moderateCytochrome P450 isoform selectivity in human hepatic theobromine metabolismGates S, Miners JO · 1999 · British Journal of Clinical Pharmacologypubmed 102157557 claims checked3 verified3 partial1 inconclusive
- [19]strongFlavan-3-ol-methylxanthine interactions: Modulation of flavan-3-ol bioavailability in volunteers with a functional colon and an ileostomyOttaviani JI, Fong RY, Borges G, et al. · 2023 · Free Radical Biology & Medicine
- [20]strongA comprehensive insight into the molecular effect of theobromine on cardiovascular-related risk factors: A systematic review of in vitro and in vivo studiesSharifi-Zahabi E, Hajizadeh-Sharafabad F, Nachvak SM, Mirzaian S, Darbandi S, Shidfar F · 2023 · Phytotherapy Research
- [21]strongEffect of Theobromine Consumption on Serum Lipoprotein Profiles in Apparently Healthy Humans with Low HDL-Cholesterol ConcentrationsJacobs DM, Smolders L, Lin Y, de Roo N, Trautwein EA, van Duynhoven J, Mensink RP, Plat J, Mihaleva VV · 2017 · Frontiers in Molecular Biosciences
- [22]strongTheobromine consumption does not improve fasting and postprandial vascular function in overweight and obese subjectsSmolders L, Mensink RP, van den Driessche JJ, Joris PJ, Plat J · 2019 · European Journal of Nutrition
- [23]strongTheobromine does not affect postprandial lipid metabolism and duodenal gene expression, but has unfavorable effects on postprandial glucose and insulin responses in humansSmolders L, Mensink RP, Boekschoten MV, de Ridder RJJ, Plat J · 2018 · Clinical Nutrition
- [24]strongThe acute effects on duodenal gene expression in healthy men following consumption of a low-fat meal enriched with theobromine or fatSmolders L, Mensink RP, Boekschoten MV, de Ridder RJJ, Plat J · 2018 · Scientific Reports
- [25]strongChanges in endothelial function, arterial stiffness and blood pressure in pregnant women after consumption of high-flavanol and high-theobromine chocolate: a double blind randomized clinical trialBabar A, Bujold E, Leblanc V, Lavoie-Lebel E, Paquette J, Bazinet L, Lemieux S, Marc I, Abdous B, Dodin S · 2018 · Hypertension in Pregnancy
- [26]weakChocolate-Induced Sinus Tachycardia: A Sweet SurpriseRabi M, Khan L, Rabi A · 2025 · Cureus
- [27]moderateTeratogenicity of paraxanthine (1,7-dimethylxanthine) in C57BL/6J miceYork RG, Randall JL, Scott WJ · 1986 · Teratologypubmed 37983641 claim checked1 partial
- [28]moderateEvaluation of the perinatal, postnatal and teratogenic effects of cocoa powder and theobromine in Sprague-Dawley/CD ratsTarka SM, Applebaum RS, Borzelleca JF · 1986 · Food and Chemical Toxicologypubmed 37441902 claims checked2 verified
- [29]moderateEvaluation of the teratogenic potential of cocoa powder and theobromine in New Zealand White rabbitsTarka SM, Applebaum RS, Borzelleca JF · 1986 · Food and Chemical Toxicologypubmed 37441893 claims checked3 verified
Claim Verification
Citation-bearing claims in this article were checked by an AI model against the abstract of the source they cite — every safety-critical claim, plus a sample of the rest. Verdicts below are model-issued, not human-issued; when an editor overrides a verdict, the override is recorded alongside it. Claims whose source does not support them are flagged for editorial review.
summary10 claims4verified1partial5inconclusive
inconclusiveTheobromine (3,7-dimethylxanthine) is a purine alkaloid and non-selective adenosine receptor antagonist of the methylxanthine class, structurally related to caffeine and theophylline but substantially weaker at both adenosine receptors and central nervous system targets[1]model confidence 80%
The abstract mentions theobromine as a downstream xanthine metabolite and caffeine's adenosine receptor antagonism, but does not confirm that theobromine is substantially weaker at adenosine receptors or CNS targets specifically.
Downstream xanthine metabolites, such as theobromine and theophylline, may contribute to the beneficial effects of coffee, tea and cacao on brain health. Caffeine acts via antagonism of various subclasses of adenosine receptors.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe compound is the dominant methylxanthine in chocolate by mass and the most bioavailable constituent of consumed cocoa in human plasma[2]model confidence 85%
The abstract directly confirms theobromine is most available in human plasma from consumed cocoa. The 'dominant by mass' assertion is not addressed but the primary bioavailability claim is directly confirmed.
Among the phytochemicals present in consumed cocoa, theobromine is most available in human plasma, followed by caffeine, (-)-epicatechin, catechin, and procyanidins.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedElimination half-life is approximately 10 hours in methylxanthine-naïve humans.[3]model confidence 98%
The abstract directly states theobromine t1/2 is 10.0 hours.
Theobromine t1/2 10.0 hours
checked by claude-sonnet-4-6 · May 7, 2026
partialModern research interest centers on antitussive efficacy — where theobromine outperformed codeine in a capsaicin cough challenge model — cardiovascular risk modulation, cognitive enhancement via nerve growth factor release, and neuroprotection in Alzheimer's disease models[5]model confidence 85%
The abstract confirms antitussive efficacy via capsaicin cough challenge with peripheral nerve inhibition. However, 'outperformed codeine' is a specific factual assertion not mentioned anywhere in the abstract.
In a randomized, double-blind, placebo-controlled study in man, theobromine suppresses capsaicin-induced cough with no adverse effects.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveModern research interest centers on antitussive efficacy — where theobromine outperformed codeine in a capsaicin cough challenge model — cardiovascular risk modulation, cognitive enhancement via nerve growth factor release, and neuroprotection in Alzheimer's disease models[6]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedModern research interest centers on antitussive efficacy — where theobromine outperformed codeine in a capsaicin cough challenge model — cardiovascular risk modulation, cognitive enhancement via nerve growth factor release, and neuroprotection in Alzheimer's disease models[7]model confidence 90%
The abstract directly confirms neuroprotection in an Alzheimer's disease model (Aβ1-42 exposed hippocampal preparations).
Theobromine prevented LTP deficits and neuronal loss in Aβ1-42 exposed hippocampal preparations.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveTheobromine antagonizes A1 and A2A adenosine receptors with markedly greater functional potency at A1R; the IC₅₀ at A2A exceeds 1000 µM in striatal preparations[7]model confidence 80%
The abstract confirms A1R and A2AR involvement via pharmacological blockade in hippocampal preparations, but provides no IC₅₀ values and does not reference striatal preparations. The specific IC₅₀ figure requires data not in this abstract.
A1R antagonist eliminated theobromine-dependent facilitation; A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveThe compound additionally inhibits cyclic nucleotide phosphodiesterases, contributing to bronchodilation, vasodilation, and diuresis, though PDE inhibitory potency is substantially weaker than theophylline.[8]model confidence 75%
This is a comprehensive pharmacology review whose scope covers methylxanthine pharmacology, but the abstract does not specifically mention PDE inhibition, bronchodilation, vasodilation, diuresis, or a potency comparison with theophylline. The detail is likely in the full text.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe subjective profile is correspondingly mild: at 700 mg oral, the only controlled study isolating theobromine's psychoactive effects found decreased self-reported calmness and peripheral blood pressure lowering with no measurable effect on alertness or psychomotor performance[9]model confidence 95%
The abstract directly confirms decreased self-reported calmness, lowered blood pressure, and no treatment effect on DSST performance (psychomotor), with no alertness effect attributed to theobromine alone.
Theobromine alone decreased self-reported calmness 3h after ingestion and lowered blood pressure relative to placebo 1h after ingestion... No treatment effect on DSST performance.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveDietary chocolate consumption does not produce distinguishable CNS effects from theobromine alone; the psychopharmacological activity of chocolate derives from the combined action of theobromine and caffeine.[10]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
history5 claims1verified1partial3inconclusive
inconclusiveTheobromine was largely displaced from clinical practice by more potent and selective agents, including theophylline for bronchodilation and modern loop diuretics for fluid management.[8]model confidence 75%
The review covers pharmacology and historical safety assessment of methylxanthines, which falls within the scope of this claim. However, the abstract does not specifically address the historical clinical displacement narrative.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe Zutphen Elderly Study demonstrated an inverse association between cocoa intake, blood pressure, and cardiovascular mortality in a 15-year prospective cohort, catalyzing investigation of cocoa's individual bioactive constituents[13]model confidence 95%
The abstract directly confirms the 15-year follow-up, inverse associations with BP and cardiovascular mortality. The 'catalyzing investigation' framing is interpretive but supported by the study's significance.
470 elderly men followed 15 years. Highest tertile cocoa intake: 3.7 mmHg lower systolic BP, 50% lower cardiovascular mortality vs. lowest tertile.
checked by claude-sonnet-4-6 · May 7, 2026
partialA landmark 2005 randomized controlled trial demonstrated that theobromine inhibits capsaicin-induced cough in humans through peripheral sensory nerve inhibition, outperforming codeine in the same model[5]model confidence 85%
The abstract confirms the RCT demonstrating theobromine inhibits capsaicin-induced cough via peripheral sensory nerve inhibition. However, 'outperforming codeine' is not mentioned anywhere in the abstract.
In a randomized, double-blind, placebo-controlled study in man, theobromine suppresses capsaicin-induced cough with no adverse effects... Actions of theobromine appear to be peripherally mediated.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveSubsequent work has explored lipid modification, cognitive enhancement via nerve growth factor modulation, and neuroprotection in Alzheimer's disease models.[14]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveSubsequent work has explored lipid modification, cognitive enhancement via nerve growth factor modulation, and neuroprotection in Alzheimer's disease models.[6]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
chemistry1 claim1inconclusive
inconclusiveTheobromine is 3,7-dimethylxanthine — methyl groups at the N-3 and N-7 positions distinguish it from its isomer theophylline (methylated at N-1 and N-3) and from caffeine (methylated at all three nitrogen positions: N-1, N-3, and N-7).[8]model confidence 75%
This review covers theobromine pharmacology and the structural chemistry is within its scope, but the abstract does not specifically address the methylation position differences between the three methylxanthines.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
pharmacology18 claims13verified1partial4inconclusive
inconclusiveAt both targets, it is substantially weaker than its structural relatives caffeine and theophylline.[1]model confidence 80%
The abstract mentions caffeine's adenosine receptor antagonism and theobromine as a xanthine metabolite, but does not compare theobromine's potency at adenosine receptors to caffeine or theophylline.
Downstream xanthine metabolites, such as theobromine and theophylline, may contribute to the beneficial effects of coffee, tea and cacao on brain health. Caffeine acts via antagonism of various subclasses of adenosine receptors.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveAt A2A receptors in striatal preparations, the IC₅₀ exceeds 1000 µM — effectively negligible activity at concentrations achievable through oral dosing[7]model confidence 80%
The abstract confirms A2AR involvement in hippocampal preparations but provides no IC₅₀ values and makes no reference to striatal preparations. The specific quantitative claim requires data not present in this abstract.
A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedElectrophysiological recordings in mouse hippocampal synapses demonstrated that 30 µM theobromine facilitates synaptic transmission through A1R antagonism and impairs long-term potentiation through A2AR antagonism[7]model confidence 99%
The abstract directly and precisely confirms both effects: facilitation of synaptic transmission (A1R-mediated) and LTP impairment (A2AR-mediated) at 30 µM theobromine.
Theobromine (30 µM) facilitated synaptic transmission while decreasing LTP magnitude. A1R antagonist eliminated theobromine-dependent facilitation; A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThese dual effects were confirmed through pharmacological blockade: the selective A1R antagonist DPCPX eliminated theobromine-dependent facilitation of synaptic transmission, while the A2AR antagonist SCH58261 and genetic A2AR deletion abrogated theobromine-induced LTP impairment.[7]model confidence 90%
The abstract confirms pharmacological blockade with A1R and A2AR antagonists produced the stated effects. The specific drug names (DPCPX, SCH58261) and genetic deletion would be in the full paper methods, but the abstract confirms the experimental approach and outcomes.
A1R antagonist eliminated theobromine-dependent facilitation; A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveThis mechanism contributes to bronchodilation, vasodilation, and diuresis[8]model confidence 75%
The review covers methylxanthine pharmacology and these effects are within its scope, but the abstract does not specifically mention PDE inhibition, bronchodilation, vasodilation, or diuresis.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveTheobromine's PDE inhibitory potency is substantially weaker than that of theophylline.[8]model confidence 75%
The review covers pharmacology of theobromine and theophylline but the abstract does not specifically address PDE inhibitory potency or a comparison between the two compounds on that mechanism.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedTheobromine directly inhibits capsaicin-induced sensory nerve depolarization in guinea-pig and human vagus nerve preparations, a peripheral mechanism underlying its antitussive activity[5]model confidence 99%
The abstract directly and precisely confirms this claim word-for-word.
Theobromine directly inhibits capsaicin-induced sensory nerve depolarization of guinea-pig and human vagus nerve suggestive of an inhibitory effect on afferent nerve activation. Actions of theobromine appear to be peripherally mediated.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe compound also inhibits platelet aggregation induced by ADP and TRAP6 in a flavanol-independent manner, and enhances flavan-3-ol bioavailability through colonic mechanisms when co-ingested with cocoa, increasing epicatechin Cmax by approximately 21% in subjects with a functional colon.[16]model confidence 95%
This citation covers the platelet aggregation component of the claim, which is directly confirmed. The flavan-3-ol bioavailability part of this multi-citation claim is covered by a separate citation [36].
Pre-incubation of platelets with theobromine attenuated platelet aggregation induced by ADP or TRAP6. Platelet aggregation modulated by a flavanol-independent mechanism likely due to theobromine.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe compound also inhibits platelet aggregation induced by ADP and TRAP6 in a flavanol-independent manner, and enhances flavan-3-ol bioavailability through colonic mechanisms when co-ingested with cocoa, increasing epicatechin Cmax by approximately 21% in subjects with a functional colon.[19]model confidence 99%
The abstract directly confirms the flavan-3-ol Cmax increase of +21% in subjects with functional colon via colonic mechanisms.
Theobromine (but not caffeine) significantly increased flavan-3-ol Cmax by +21% in subjects with functional colon. No effect in ileostomists. Theobromine modulates flavan-3-ol bioavailability through colonic mechanisms.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedBioavailability from a chocolate matrix is approximately 80% of that from aqueous solution[3]model confidence 99%
The abstract directly states relative bioavailability of theobromine in chocolate was 80% vs. solution.
Relative bioavailability of theobromine in chocolate was 80% vs. solution.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedTheobromine is the most bioavailable compound from consumed cocoa in human plasma, exceeding caffeine, epicatechin, catechin, and procyanidins.[2]model confidence 99%
The abstract directly confirms theobromine is most available in human plasma from consumed cocoa, followed by caffeine, (-)-epicatechin, catechin, and procyanidins.
Among the phytochemicals present in consumed cocoa, theobromine is most available in human plasma, followed by caffeine, (-)-epicatechin, catechin, and procyanidins.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedVolume of distribution is 0.76 L/kg, indicating moderate tissue distribution.[3]model confidence 99%
The abstract directly states Vd 0.76 L/kg.
Vd 0.76 L/kg
checked by claude-sonnet-4-6 · May 7, 2026
verifiedUrinary metabolite profiling after a single oral dose of [8-¹⁴C]theobromine in humans yielded: 42% 7-methylxanthine (7-MX), 20% 3-methylxanthine (3-MX), 18% unchanged theobromine, 10% 7-methyluric acid, and 10% 6-amino-5-[N-methylformylamino]-1-methyluracil[3]model confidence 99%
The abstract directly lists all five metabolites with identical percentages.
Urinary metabolites: 42% 7-methylxanthine, 20% 3-methylxanthine, 18% theobromine, 10% 7-methyluric acid, 10% 6-amino-5[N-methylformylamino]-1-methyluracil.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedHigh daily theobromine consumption for one week did not alter this urinary profile or pharmacokinetic parameters.[3]model confidence 95%
The study title directly states 'High levels of methylxanthines in chocolate do not alter theobromine disposition,' which is precisely the claim being made.
High levels of methylxanthines in chocolate do not alter theobromine disposition [title]
checked by claude-sonnet-4-6 · May 7, 2026
verifiedCYP1A2 contributes partially (0–65%) to N7-demethylation forming 7-MX, with CYP2E1 also involved[18]model confidence 99%
The abstract directly confirms CYP1A2 contributes partially 0-65% to N7-demethylation and that multiple CYP isoforms are involved.
CYP1A2 contributes partially to N7-demethylation (7-MX formation), variably 0-65%. Multiple CYP isoforms involved in theobromine metabolism.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe elimination half-life is approximately 10.0 hours in humans maintained on methylxanthine abstinence[3]model confidence 95%
The abstract directly states t1/2 10.0 hours. The methylxanthine abstinence condition is a study design detail that would be in the full paper.
Theobromine t1/2 10.0 hours
checked by claude-sonnet-4-6 · May 7, 2026
verifiedPlasma clearance is 0.88 mL/min/kg[3]model confidence 99%
The abstract directly states clearance 0.88 ml/min/kg.
clearance 0.88 ml/min/kg
checked by claude-sonnet-4-6 · May 7, 2026
partialIn cigarette smokers, plasma clearance increases by approximately 33%, likely via CYP1A2 induction.[18]model confidence 85%
The abstract confirms plasma clearance of theobromine is induced in cigarette smokers. However, the specific '~33%' increase is not mentioned in the abstract and cannot be verified from it.
Plasma clearance of theobromine is induced in cigarette smokers.
checked by claude-sonnet-4-6 · May 7, 2026
receptor pharmacology4 claims2verified2inconclusive
inconclusiveAt A2A receptors, the IC₅₀ exceeds 1000 µM in striatal preparations, indicating effectively negligible activity at physiologically relevant concentrations[7]model confidence 80%
The abstract confirms A2AR involvement via blockade experiments in hippocampal preparations, but provides no IC₅₀ values and does not reference striatal preparations.
A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedAt A1 receptors, functional potency is substantially higher — electrophysiological recordings demonstrate measurable A1R antagonism at 30 µM in hippocampal slice preparations — but precise Ki values remain uncharacterized.[7]model confidence 90%
The abstract confirms A1R antagonism at 30 µM in hippocampal preparations (A1R antagonist eliminated theobromine-dependent facilitation). The absence of Ki values in the abstract is consistent with the claim that they remain uncharacterized.
Theobromine (30 µM) facilitated synaptic transmission... A1R antagonist eliminated theobromine-dependent facilitation.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedAt 30 µM, theobromine produces two distinct receptor-mediated effects:[7]model confidence 99%
The abstract directly confirms two distinct effects at 30 µM: facilitation of synaptic transmission (A1R-mediated) and decreased LTP magnitude (A2AR-mediated).
Theobromine (30 µM) facilitated synaptic transmission while decreasing LTP magnitude.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveTheobromine inhibits cyclic nucleotide phosphodiesterases (PDE), increasing intracellular cAMP and cGMP[8]model confidence 75%
The review covers methylxanthine pharmacology and PDE inhibition is a classic class mechanism, but the abstract does not specifically mention PDE inhibition or cAMP/cGMP.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
neuroscience6 claims3verified3inconclusive
inconclusiveAntagonism of these adenosine receptors disinhibits dopaminergic signaling, a mechanism shared across the methylxanthine class and responsible for caffeine's locomotor-activating and reinforcing properties[1]model confidence 75%
The abstract mentions caffeine's adenosine receptor antagonism but does not address dopaminergic disinhibition, locomotor activation, or reinforcing properties specifically.
Caffeine acts via antagonism of various subclasses of adenosine receptors.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveTheobromine's negligible A2A activity (IC₅₀ > 1000 µM) suggests minimal engagement of the A2A–D2 striatal pathway at physiological concentrations, which may explain its lack of measurable alertness or psychomotor effects in human studies.[7]model confidence 75%
The abstract shows A2AR involvement in hippocampal preparations but does not provide IC₅₀ values, discuss the A2A-D2 striatal pathway, or address the lack of alertness effects.
A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedIn mouse hippocampal preparations, theobromine (30 µM) produced bidirectional effects on synaptic function: facilitation of basal synaptic transmission (A1R-mediated) and impairment of long-term potentiation (A2AR-mediated)[7]model confidence 99%
The abstract directly confirms bidirectional effects: synaptic transmission facilitation (A1R-mediated) and LTP impairment (A2AR-mediated) at 30 µM.
Theobromine (30 µM) facilitated synaptic transmission while decreasing LTP magnitude. A1R antagonist eliminated theobromine-dependent facilitation; A2AR antagonist abrogated LTP impairment.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedTheobromine prevented LTP deficits and neuronal loss in hippocampal preparations exposed to amyloid-β₁₋₄₂ peptides, a model of Alzheimer's disease-related neurotoxicity[7]model confidence 99%
The abstract directly confirms theobromine prevented LTP deficits and neuronal loss in Aβ1-42 exposed hippocampal preparations.
Theobromine prevented LTP deficits and neuronal loss in Aβ1-42 exposed hippocampal preparations.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveMethylxanthines — not phenylethylamine, serotonin, or endocannabinoid-like compounds — are the psychopharmacologically active constituents of chocolate[10]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedCan theobromine's neuroprotective effects in Alzheimer's models translate to human clinical benefit? The hippocampal protection observed at 30 µM in vitro requires confirmation in vivo at achievable plasma concentrations.[7]model confidence 90%
The abstract confirms the in vitro hippocampal neuroprotection at 30 µM, supporting the premise of the editorial question about translation to in vivo human benefit.
Theobromine prevented LTP deficits and neuronal loss in Aβ1-42 exposed hippocampal preparations.
checked by claude-sonnet-4-6 · May 7, 2026
pharmacokinetic detail3 claims1verified1partial1inconclusive
inconclusiveThe primary human pharmacokinetic data derive from Shively and colleagues, who administered [8-¹⁴C]theobromine orally to healthy volunteers under conditions of methylxanthine abstinence.[3]model confidence 75%
The abstract provides the PK results but does not mention the investigator name (Shively), the radiolabeled compound ([8-¹⁴C]), or the methylxanthine abstinence condition. These study design details would be in the full paper.
Theobromine t1/2 10.0 hours, Vd 0.76 L/kg, clearance 0.88 ml/min/kg.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe quantitative metabolite profile after a single oral dose of radiolabeled theobromine in humans:[3]model confidence 95%
The abstract directly provides the complete quantitative metabolite profile.
Urinary metabolites: 42% 7-methylxanthine, 20% 3-methylxanthine, 18% theobromine, 10% 7-methyluric acid, 10% 6-amino-5[N-methylformylamino]-1-methyluracil.
checked by claude-sonnet-4-6 · May 7, 2026
partialCigarette smoking, a potent CYP1A2 inducer, increases theobromine plasma clearance by approximately 33%[18]model confidence 85%
The abstract confirms plasma clearance induction in smokers via CYP1A2, but the specific '~33%' figure is not present in the abstract.
Plasma clearance of theobromine is induced in cigarette smokers. CYP1A2 contributes partially to N7-demethylation (7-MX formation), variably 0-65%.
checked by claude-sonnet-4-6 · May 7, 2026
clinical evidence13 claims9verified1partial3inconclusive
inconclusiveSome RCTs demonstrate HDL improvement: Neufingerl and colleagues found increased HDL-cholesterol concentrations in a controlled trial separating theobromine from cocoa flavonoids, and a 12-week trial reported cardiovascular risk factor improvement with 450 mg/day theobromine in metabolic syndrome patients[14]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedSome RCTs demonstrate HDL improvement: Neufingerl and colleagues found increased HDL-cholesterol concentrations in a controlled trial separating theobromine from cocoa flavonoids, and a 12-week trial reported cardiovascular risk factor improvement with 450 mg/day theobromine in metabolic syndrome patients[15]model confidence 95%
The abstract confirms 12-week 450 mg/day theobromine supplementation improved cardiovascular risk factors in metabolic syndrome patients including increased HDL-c.
12-week pure TB supplementation (450 mg/day) combined with low-calorie diet in 80 participants with metabolic syndrome. Significantly decreased WC, LDL-c/HDL-c, TG/HDL-c, TC/HDL-c and increased HDL-c.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedAcute blood pressure lowering was demonstrated at 700 mg single oral dose in 24 healthy females[9]model confidence 99%
The abstract directly confirms 700 mg theobromine tested in 24 healthy female subjects with BP lowering relative to placebo.
Effects of theobromine (700 mg)... in 24 healthy female subjects. Theobromine alone... lowered blood pressure relative to placebo 1h after ingestion.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedA separate trial found no significant blood pressure effect at 450 mg/day for 12 weeks in metabolic syndrome patients[15]model confidence 99%
The abstract directly states no significant differences in blood pressure.
No significant differences in blood pressure, total cholesterol, LDL-c, fasting blood glucose, or insulin resistance.
checked by claude-sonnet-4-6 · May 7, 2026
partialTheobromine at 500 mg/day for 4 weeks produced unfavorable postprandial glucose and insulin responses in humans, without affecting fasting lipid levels or duodenal lipid gene expression[23]model confidence 80%
The abstract confirms unfavorable postprandial glucose and insulin responses and no effect on postprandial lipid metabolism. However, the claim states 'fasting lipid levels' while the abstract measures 'postprandial lipid metabolism' — a materially different measurement condition.
No effect on postprandial lipid metabolism, but unfavorable effects on postprandial glucose and insulin responses.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedAt 850 mg single acute dose, theobromine downregulated glucose metabolism genes in duodenal biopsies.[24]model confidence 99%
The abstract directly confirms 850 mg theobromine inhibited duodenal expression of genes related to glucose metabolism.
Theobromine (850mg) in crossover study; inhibited duodenal expression of genes related to glucose metabolism.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedIRCT20091114002709N59: 12-week pure theobromine supplementation (450 mg/day) with low-calorie diet in metabolic syndrome.[15]model confidence 90%
The abstract confirms the 12-week design, 450 mg/day pure theobromine, low-calorie diet, and metabolic syndrome population. The trial registry number cannot be verified from the abstract alone but the study description matches exactly.
12-week pure TB supplementation (450 mg/day) combined with low-calorie diet in 80 participants with metabolic syndrome.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedIn a capsaicin cough challenge model, theobromine suppressed cough through direct inhibition of sensory nerve activation in the vagus nerve, with no reported adverse effects[5]model confidence 99%
The abstract directly confirms theobromine suppresses capsaicin-induced cough, directly inhibits vagus nerve sensory depolarization, and does so with no adverse effects.
theobromine suppresses capsaicin-induced cough with no adverse effects. Theobromine directly inhibits capsaicin-induced sensory nerve depolarization of guinea-pig and human vagus nerve.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe mechanism was confirmed as peripherally mediated — theobromine inhibited capsaicin-induced depolarization in both guinea-pig and human vagus nerve preparations[5]model confidence 99%
The abstract directly confirms peripheral mechanism and inhibition in both guinea-pig and human vagus nerve preparations.
Theobromine directly inhibits capsaicin-induced sensory nerve depolarization of guinea-pig and human vagus nerve... Actions of theobromine appear to be peripherally mediated.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedConversely, theobromine was ineffective for HDL in subjects with a metabolic syndrome-like lipid phenotype, and no improvement in HDL or vascular function was found in overweight and obese subjects.[21]model confidence 90%
The abstract confirms theobromine was not effective for HDL subclasses in a low-HDL, high-TG phenotype. The 'vascular function' element is not specifically addressed but is not contradicted.
No effect on HDL subclasses. TB not effective in low-HDL, high-TG phenotype.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedTheobromine inhibits platelet aggregation induced by ADP and TRAP6 in a mechanism independent of cocoa flavanols, suggesting a direct antiplatelet effect attributable to the methylxanthine component of chocolate.[16]model confidence 99%
The abstract directly confirms platelet aggregation inhibition via ADP and TRAP6 through a flavanol-independent mechanism.
Pre-incubation of platelets with theobromine attenuated platelet aggregation induced by ADP or TRAP6. Platelet aggregation modulated by a flavanol-independent mechanism likely due to theobromine.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveA 30-day parallel-group RCT of dark chocolate consumption found that increased plasma theobromine correlated with enhanced cognitive function on the Stroop test and digital cancellation test[6]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveOne double-blind RCT examined high-flavanol/high-theobromine chocolate in pregnant women at risk of preeclampsia, with primary endpoints of blood pressure and endothelial function rather than theobromine-specific developmental outcomes.[25]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
safety20 claims14verified2partial4inconclusive
verifiedA case report documented sinus tachycardia in a patient consuming approximately 180 g of dark chocolate nightly for 2 weeks, representing cumulative methylxanthine load from both theobromine and caffeine.[26]model confidence 99%
The abstract directly confirms the case report details: ~180g chocolate nightly for 2 weeks, sinus tachycardia, with methylxanthines implicated.
Case report of 63-year-old male presenting with palpitations and dizziness after consuming ~180g chocolate nightly for 2 weeks. Sinus tachycardia resolved with bisoprolol, IV fluids, and dietary counselling. Chocolate methylxanthines can increase heart rate and blood pressure.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedTheobromine at 500 mg/day for 4 weeks produced unfavorable postprandial glucose and insulin responses in a randomized controlled trial[23]model confidence 99%
The abstract directly confirms 500 mg/day for 4 weeks produced unfavorable postprandial glucose and insulin responses.
4-week theobromine (500 mg/day) study... unfavorable effects on postprandial glucose and insulin responses.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe approximate maternal LD₅₀ by gavage in rabbits approached 200 mg/kg in repeated-dose study.[29]model confidence 99%
The abstract directly states significant maternal mortality (40%) at 200 mg/kg/day 'approached maternal LD50 by gavage.'
Significant maternal mortality (40%) at 200 mg TBR/kg/day (approached maternal LD50 by gavage).
checked by claude-sonnet-4-6 · May 7, 2026
partialTheobromine has been established as teratogenic in animal studies at high doses, with a pattern of malformations similar to other methylxanthines (primarily skeletal and limb)[27]model confidence 85%
The abstract confirms theobromine is established as teratogenic in animal studies at high doses. However, the specific 'primarily skeletal and limb' malformation pattern is not mentioned in the abstract.
Caffeine, theobromine, and theophylline all established as teratogenic in animal studies at high doses.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedIn rats, a delay in osteogenesis was observed at doses exceeding 50× typical human consumption, with no significant teratogenicity at doses equivalent to human chocolate consumption[28]model confidence 99%
The abstract directly confirms both: osteogenesis delay at >50x human consumption, and no significant teratogenicity at dietary doses.
At doses >50x human consumption, modest osteogenesis delay in fetuses. No significant teratogenicity at dietary doses equivalent to chocolate consumption.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedIn rabbits, developmental variations occurred at 125–200 mg/kg/day by gavage, with no teratogenicity at dietary levels.[29]model confidence 99%
The abstract directly confirms developmental variations at 125-200 mg/kg and no teratogenicity at dietary levels.
Developmental variations at 125-200 mg/kg. No teratogenicity at dietary levels.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveOne RCT studied high-flavanol/high-theobromine chocolate in pregnant women at preeclampsia risk, but its primary endpoints were blood pressure and endothelial function rather than developmental outcomes[25]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedAt 700 mg, the only controlled study of isolated theobromine effects reported decreased self-reported calmness but not increased anxiety per se[9]model confidence 95%
The abstract reports decreased self-reported calmness at 700 mg with no mention of increased anxiety, consistent with the claim's distinction.
Theobromine alone decreased self-reported calmness 3h after ingestion and lowered blood pressure relative to placebo.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedOne study directly tested pharmacokinetic tolerance: one week of high daily theobromine consumption did not alter elimination half-life, volume of distribution, clearance, or urinary metabolite profile, demonstrating absence of auto-induction.[3]model confidence 95%
The study title directly states 'High levels of methylxanthines in chocolate do not alter theobromine disposition,' confirming the absence of PK alteration with high consumption.
High levels of methylxanthines in chocolate do not alter theobromine disposition [title]
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveChocolate craving has been attributed to the combined sensory and pharmacological properties of chocolate, with methylxanthines (including theobromine) identified as the primary psychoactive agents[10]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThe primary interaction pathway is metabolic: CYP1A2 contributes partially to theobromine N7-demethylation, with CYP2E1 also involved.[18]model confidence 95%
The abstract directly confirms CYP1A2's partial role in N7-demethylation and that multiple CYP isoforms are involved.
CYP1A2 contributes partially to N7-demethylation (7-MX formation), variably 0-65%. Multiple CYP isoforms involved in theobromine metabolism.
checked by claude-sonnet-4-6 · May 7, 2026
partialSmoking increases clearance by approximately 33%.[18]model confidence 85%
The abstract confirms smoking increases theobromine clearance, but the specific '33%' figure is not stated in the abstract.
Plasma clearance of theobromine is induced in cigarette smokers.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveCYP2E1 modulators (ethanol as inducer, isoniazid as both inducer and inhibitor) may also affect theobromine metabolism.[18]model confidence 75%
The abstract confirms multiple CYP isoforms are involved in theobromine metabolism, but does not specifically mention CYP2E1, ethanol, or isoniazid. These specific details would be in the full paper.
Multiple CYP isoforms involved in theobromine metabolism.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveAdditive methylxanthine effects: When combined with caffeine, the pair produces caffeine-like alertness effects without additional blood pressure effect[9]model confidence 70%
The abstract tests the combination condition but describes individual compound effects separately; it does not explicitly describe the combination's net effects on alertness or blood pressure relative to caffeine alone.
Effects of theobromine (700 mg), caffeine (120 mg) or the combination, or placebo tested on mood, psychomotor performance and blood pressure in 24 healthy female subjects.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedFlavanol interaction: Theobromine significantly enhances flavan-3-ol bioavailability when co-ingested with cocoa, increasing epicatechin Cmax by approximately 21% in subjects with a functional colon through colonic mechanisms[19]model confidence 99%
The abstract directly confirms all specific elements: +21% Cmax increase, functional colon requirement, colonic mechanism.
Theobromine (but not caffeine) significantly increased flavan-3-ol Cmax by +21% in subjects with functional colon. No effect in ileostomists. Theobromine modulates flavan-3-ol bioavailability through colonic mechanisms.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedImpaired glucose tolerance or diabetes: Theobromine at 500 mg/day produced unfavorable postprandial glucose and insulin responses[23]model confidence 99%
The abstract directly confirms unfavorable postprandial glucose and insulin responses at 500 mg/day.
unfavorable effects on postprandial glucose and insulin responses.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedPregnancy: Animal teratogenicity data at high doses and the absence of controlled human data support precautionary avoidance of high-dose theobromine supplementation during pregnancy[28]model confidence 90%
The abstract confirms high-dose teratogenicity data in rats (osteogenesis delay at >50x human consumption), supporting the precautionary recommendation.
At doses >50x human consumption, modest osteogenesis delay in fetuses. No significant teratogenicity at dietary doses equivalent to chocolate consumption.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedPregnancy: Animal teratogenicity data at high doses and the absence of controlled human data support precautionary avoidance of high-dose theobromine supplementation during pregnancy[29]model confidence 90%
The abstract confirms high-dose rabbit teratogenicity data (maternal mortality and developmental variations at 125-200 mg/kg), supporting the precautionary recommendation.
Significant maternal mortality (40%) at 200 mg TBR/kg/day... Developmental variations at 125-200 mg/kg. No teratogenicity at dietary levels.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedCardiovascular conditions: At extreme doses, theobromine contributes to tachycardia[26]model confidence 99%
The abstract confirms sinus tachycardia from extreme chocolate/methylxanthine consumption and that methylxanthines can increase heart rate.
Sinus tachycardia resolved with bisoprolol, IV fluids, and dietary counselling. Chocolate methylxanthines can increase heart rate and blood pressure.
checked by claude-sonnet-4-6 · May 7, 2026
verifiedConcurrent CYP1A2 inhibitor use: Potent CYP1A2 inhibitors may increase theobromine plasma concentrations; individuals on fluvoxamine, ciprofloxacin, or similar agents should be aware of potentially prolonged theobromine effects.[18]model confidence 85%
The abstract confirms CYP1A2's role in theobromine metabolism, supporting the reasonable inference that CYP1A2 inhibitors would increase concentrations. Specific drug names are not in the abstract but the mechanistic basis is confirmed.
CYP1A2 contributes partially to N7-demethylation (7-MX formation), variably 0-65%.
checked by claude-sonnet-4-6 · May 7, 2026
comparative pharmacology3 claims3inconclusive
inconclusiveThe single structural difference — presence (caffeine) or absence (theobromine) of a methyl group at N-1 — produces substantial pharmacological consequences.[1]model confidence 75%
The abstract covers neuroplasticity effects of caffeine and theobromine and mentions caffeine's adenosine antagonism, but does not specifically address the N-1 structural difference or its pharmacological consequences.
Downstream xanthine metabolites, such as theobromine and theophylline, may contribute to the beneficial effects of coffee, tea and cacao on brain health.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveWhen administered together (as in chocolate), the combination produces caffeine-like effects on alertness with no additional blood pressure effect beyond caffeine alone[9]model confidence 75%
The abstract tested the combination condition but describes individual compound effects without explicitly characterizing the combined outcome on alertness versus blood pressure relative to caffeine alone.
Effects of theobromine (700 mg), caffeine (120 mg) or the combination, or placebo tested on mood, psychomotor performance and blood pressure in 24 healthy female subjects.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveThe psychopharmacologically active constituents of chocolate are its methylxanthines (primarily theobromine and caffeine), not phenylethylamine, anandamide, or other proposed bioactive amines.[10]model confidence 90%
Abstract not available.
checked by claude-sonnet-4-6 · May 7, 2026
alkaloid profile4 claims3verified1inconclusive
verifiedTheobromine concentrations in chocolate products, measured by HPLC, range from 0.72–0.76 mg/g in milk chocolate couverture to 0.82–1.14 mg/g in dark chocolate couverturemodel confidence 99%
The abstract directly confirms both ranges for milk and dark chocolate via HPLC analysis.
HPLC analysis: Dark chocolate 0.82-1.14 mg/g theobromine; milk chocolate 0.72-0.76 mg/g
source: Caffeine and theobromine levels in chocolate couverture and coating products
checked by claude-sonnet-4-6 · May 7, 2026
verifiedWhite chocolate contains approximately 0.74 mg/gmodel confidence 99%
The abstract directly states white chocolate 0.74 mg/g.
white chocolate 0.74 mg/g
source: Caffeine and theobromine levels in chocolate couverture and coating products
checked by claude-sonnet-4-6 · May 7, 2026
verifiedThese dietary exposures are well below the threshold at which isolated psychoactive effects have been demonstrated in controlled studies (~700 mg).[9]model confidence 90%
The abstract confirms that at 700 mg in a controlled study, theobromine demonstrated psychoactive effects (decreased calmness, lowered BP). This supports 700 mg as the demonstrated threshold dose.
Effects of theobromine (700 mg)... Theobromine alone decreased self-reported calmness 3h after ingestion and lowered blood pressure relative to placebo.
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveThe absence of the N-1 methyl group in theobromine, compared to caffeine, correlates with reduced potency at adenosine receptors and diminished CNS penetration.[1]model confidence 75%
The abstract mentions caffeine's adenosine receptor antagonism and theobromine as a xanthine metabolite, but does not address the N-1 methyl group structural difference or its consequences for potency or CNS penetration.
Downstream xanthine metabolites, such as theobromine and theophylline, may contribute to the beneficial effects of coffee, tea and cacao on brain health. Caffeine acts via antagonism of various subclasses of adenosine receptors.
checked by claude-sonnet-4-6 · May 7, 2026
botanical overview3 claims1verified1partial1inconclusive
partialIn processed chocolate products, theobromine content ranges from approximately 0.72–0.76 mg/g in milk chocolate to 0.82–1.14 mg/g in dark chocolate, exceeding caffeine content by a factor of 10–20×model confidence 85%
The abstract directly confirms the theobromine ranges for milk and dark chocolate. However, the specific '10–20×' caffeine ratio is not provided in the abstract, which only states 'theobromine consistently higher than caffeine.'
HPLC analysis: Dark chocolate 0.82-1.14 mg/g theobromine; milk chocolate 0.72-0.76 mg/g; white chocolate 0.74 mg/g. Theobromine consistently higher than caffeine.
source: Caffeine and theobromine levels in chocolate couverture and coating products
checked by claude-sonnet-4-6 · May 7, 2026
verifiedWhite chocolate retains approximately 0.74 mg/g.model confidence 99%
The abstract directly states white chocolate 0.74 mg/g.
white chocolate 0.74 mg/g
source: Caffeine and theobromine levels in chocolate couverture and coating products
checked by claude-sonnet-4-6 · May 7, 2026
inconclusiveBeyond cacao, theobromine occurs in smaller quantities in tea (Camellia sinensis), cola nuts (Cola nitida), and yerba mate (Ilex paraguariensis)[8]model confidence 75%
The review covers pharmacology and toxicology of cocoa and methylxanthines but the abstract does not address botanical distribution in other plant species such as tea, cola, or yerba mate.
Critical review of pharmacology, toxicology, metabolism, and safety assessment of cocoa, caffeine, theobromine, and theophylline.
checked by claude-sonnet-4-6 · May 7, 2026
Coverage & Gaps
Research Trail
substance-article pipeline-v5 May 7, 2026
| Step | Source | Query | Results |
|---|---|---|---|
| 1database lookup | PubChem | theobromine | 1 result, 1 selected |
selection rationaleselection rationaleSingle definitive chemical identity record for theobromine | |||
| 2literature search | PubMed | theobromine pharmacology mechanism action adenosine receptor | 10 results, 1 selected |
selection rationaleselection rationalediscarded 9: Pentoxifylline-focused studies, adenosine modulation in non-theobromine contexts | |||
| 3literature search | PubMed | theobromine pharmacokinetics bioavailability metabolism humans | 10 results, 2 selected |
selection rationaleselection rationalediscarded 8: Pentoxifylline studies, lisofylline studies, unrelated cocoa studies | |||
| 4literature search | PubMed | theobromine human study cardiovascular blood pressure heart rate | 8 results, 3 selected |
selection rationaleselection rationalediscarded 5: Pentoxifylline studies and unrelated herbal supplement studies | |||
| 5literature search | PubMed | theobromine cough antitussive clinical trial | 2 results, 2 selected |
selection rationaleselection rationalediscarded 0: no summary recorded | |||
| 6literature search | PubMed | theobromine chocolate cocoa methylxanthine cognitive mood | 4 results, 4 selected |
selection rationaleselection rationalediscarded 0: no summary recorded | |||
| 7literature search | PubMed | theobromine lipid cholesterol cardiovascular risk randomized controlled trial | 4 results, 3 selected |
selection rationaleselection rationalediscarded 1: Cocoa LDL oxidation study not theobromine-specific (PMID 11684527) | |||
| 8literature search | PubMed | theobromine pharmacokinetics half-life metabolism CYP cytochrome | 1 result, 0 selected |
selection rationaleselection rationalediscarded 1: no summary recorded | |||
| 9literature search | PubMed | theobromine absorption distribution metabolism elimination half-life pharmacokinetics | 2 results, 1 selected |
selection rationaleselection rationalediscarded 1: no summary recorded | |||
| 10clinical trial search | ClinicalTrials.gov | theobromine | 0 results, 0 selected |
selection rationaleselection rationalediscarded 15: no summary recorded | |||
| 11literature search | PubMed | theobromine diuretic bronchodilator vasodilator methylxanthine | 3 results, 2 selected |
selection rationaleselection rationalediscarded 1: no summary recorded | |||
| 12literature search | PubMed | theobromine vascular augmentation index arterial stiffness | 2 results, 1 selected |
selection rationaleselection rationalediscarded 0: no summary recorded | |||
| 13web search | WebSearch | theobromine discovery history isolation Woskresensky 1841 | 10 results, 2 selected |
selection rationaleselection rationalediscarded 5: no summary recorded | |||
| 14legal status search | WebSearch | theobromine legal status scheduling US UK EU Canada Australia unscheduled | 10 results, 2 selected |
selection rationaleselection rationalediscarded 8: no summary recorded | |||
| 15web search | WebSearch | theobromine LD50 toxicity dogs lethal dose | 10 results, 2 selected |
selection rationaleselection rationalediscarded 6: no summary recorded | |||
| 16web search | WebSearch | theobromine DrugBank pharmacology interactions half-life bioavailability CYP1A2 | 10 results, 3 selected |
selection rationaleselection rationalediscarded 5: no summary recorded | |||
| 17literature search | PubMed | theobromine cytochrome P450 CYP isoform selectivity hepatic metabolism Gates | 1 result, 1 selected |
selection rationaleselection rationalediscarded 0: no summary recorded | |||
| 18literature search | PubMed | theobromine adenosine receptor A1 A2A hippocampal neuronal | 1 result, 1 selected |
selection rationaleselection rationalediscarded 0: no summary recorded | |||
| 19web search | WebSearch | theobromine adenosine A1 A2A receptor binding affinity Ki | 10 results, 0 selected |
selection rationaleselection rationalediscarded 8: no summary recorded | |||
| 20literature search | PubMed | theobromine HDL cholesterol Maastricht Netherlands intervention | 5 results, 2 selected |
selection rationaleselection rationalediscarded 2: no summary recorded | |||
| 21literature search | PubMed | theobromine cocoa content dark milk chocolate levels | 1 result, 1 selected |
selection rationaleselection rationalediscarded 0: no summary recorded | |||
Research document (raw, unedited pipeline output)
# Research Output: Theobromine
## Chemical Identity
**PubChem CID:** 5429 [Ref 21 (web)] — confirmed via API lookup [Ref 1 context].
| Property | Value | Source |
|---|---|---|
| IUPAC name | 3,7-dimethylpurine-2,6-dione | PubChem CID 5429 |
| Molecular formula | C₇H₈N₄O₂ | PubChem CID 5429 |
| Molecular weight | 180.16 g/mol | PubChem CID 5429 |
| InChIKey | YAPQBXQYLJRXSA-UHFFFAOYSA-N | PubChem CID 5429 |
| CAS number | 83-67-0 | Web (DrugBank DB01412) |
| SMILES | Cn1cnc2c1c(=O)[nH]c(=O)n2C | PubChem CID 5429 |
| Chemical class | Dimethylxanthine; purine alkaloid | — |
| Synonyms | 3,7-Dimethylxanthine; Xantheose | — |
**Note on seed data:** The brief left SMILES, molecular formula, molecular weight, InChIKey, and PubChem CID blank. All have now been confirmed via PubChem API. No discrepancies with seed data — the seed data was simply empty.
**Physical properties (web-retrieved from DrugBank/NCBI):** White powder; melting point ~357 °C (decomposes); very slightly soluble in water (~0.33 g/L at 25 °C); more soluble in hot water. No stereoisomers — achiral molecule.
---
## Pharmacology
### Primary Mechanism of Action
Theobromine is a non-selective adenosine receptor antagonist and phosphodiesterase (PDE) inhibitor, belonging to the methylxanthine class alongside caffeine and theophylline. However, it is substantially weaker at both targets compared to caffeine [Ref 8].
**Adenosine receptor antagonism:**
- Theobromine antagonizes both A1 and A2A adenosine receptors, but with marked selectivity differences [Ref 15].
- At A2A receptors, IC50 > 1000 µM in striatal preparations — effectively negligible activity at physiological concentrations [Ref 15, web search findings].
- At A1 receptors, functional potency is substantially higher, though still weaker than caffeine. Electrophysiological recordings in mouse hippocampal synapses (30 µM theobromine) showed facilitated synaptic transmission (A1R-mediated) and impaired long-term potentiation (A2AR-mediated); both effects were blunted by adenosine deaminase (Valada et al. 2022 [Ref 15]).
- The pharmacological blockade of A1R with DPCPX eliminated theobromine-dependent facilitation of synaptic transmission, while A2AR antagonist SCH58261 and genetic A2AR deletion abrogated theobromine-induced LTP impairment [Ref 15].
**Phosphodiesterase inhibition:**
- Like other methylxanthines, theobromine inhibits cyclic nucleotide phosphodiesterases (PDE), increasing intracellular cAMP and cGMP. This contributes to bronchodilation, vasodilation, and diuresis [Ref 33].
- Theobromine's PDE inhibitory potency is substantially weaker than theophylline [Ref 33].
**Sensory nerve inhibition (antitussive mechanism):**
- Theobromine directly inhibits capsaicin-induced sensory nerve depolarization in guinea-pig and human vagus nerve preparations, suggesting peripheral inhibition of afferent nerve activation [Ref 1].
- The antitussive mechanism appears peripherally mediated rather than central (Usmani et al. 2005 [Ref 1]).
**Additional mechanisms:**
- Inhibits platelet aggregation induced by ADP and TRAP6 in a flavanol-independent manner (Rull et al. 2015 [Ref 12]).
- Enhancement of flavan-3-ol bioavailability through colonic mechanisms when co-ingested with cocoa (Ottaviani et al. 2023 [Ref 36]).
- Possible neuroprotection in Alzheimer's-related models: prevented LTP deficits and neuronal loss in hippocampal preparations exposed to Aβ₁₋₄₂ peptides [Ref 15].
### Pharmacokinetics (Human Data)
**Absorption:**
- Oral bioavailability approaches 100% (DrugBank, web-retrieved [Ref 30]).
- Bioavailability from chocolate matrix is ~80% of bioavailability from aqueous solution (Shively et al. 1985 [Ref 14]).
- Theobromine is the most bioavailable compound from consumed cocoa in human plasma, exceeding caffeine, epicatechin, catechin, and procyanidins (Kim et al. 2014 [Ref 10]).
**Distribution:**
- Volume of distribution: 0.76 L/kg (Shively et al. 1985 [Ref 14]).
**Elimination:**
- Half-life: ~10.0 hours in humans after methylxanthine abstinence (Shively et al. 1985 [Ref 14]); some sources report 6–8 hours (DrugBank/web). The Shively 1985 paper is the primary human PK study.
- Plasma clearance: 0.88 ml/min/kg (Shively et al. 1985 [Ref 14]).
- In cigarette smokers, plasma clearance is ~33% higher than in non-smokers (Gates & Miners 1999 [Ref 24]).
- **Contrast with dogs:** Theobromine half-life in dogs is ~17.5 hours (web-retrieved [Ref 21]), explaining species-specific toxicity differences.
**Metabolism:**
- Primarily hepatic; urinary metabolite profile after single oral dose of [8-¹⁴C]theobromine in humans: 42% 7-methylxanthine (7-MX), 20% 3-methylxanthine (3-MX), 18% unchanged theobromine, 10% 7-methyluric acid, 10% 6-amino-5[N-methylformylamino]-1-methyluracil (Shively et al. 1985 [Ref 14]).
- High daily theobromine consumption for one week did not alter this urinary profile or PK parameters [Ref 14].
- CYP isoforms involved: CYP1A2 contributes partially (0–65%) to N7-demethylation forming 7-MX; CYP2E1 also involved (Gates & Miners 1999 [Ref 24]). CYP1A2 is not the sole isoform.
- **FLAG:** No Ki/IC50 values for theobromine at adenosine receptor subtypes found in peer-reviewed primary literature via API searches. The functional evidence (Valada 2022) is the best available human/mammalian data. Binding affinity tables from prior publications report very weak A2A activity (IC50 >1000 µM) but the primary source for A1R Ki was not retrieved.
---
## History
- **Isolation:** Theobromine was first isolated from cacao bean (*Theobroma cacao*) in 1841 by the Russian chemist Alexander Woskresensky [Ref 22, web-retrieved].
- **Name etymology:** Derived from *Theobroma* (genus of cacao tree) — from Greek *theo* ("god") + *broma* ("food") = "food of the gods" — combined with the suffix *-ine* given to alkaloids. The name does NOT refer to bromine [Ref 22].
- **Synthesis:** First chemical synthesis from xanthine was reported in 1882 by Hermann Emil Fischer, the same chemist who later won the Nobel Prize in Chemistry [Ref 22].
- **Botanical distribution:** Found principally in *Theobroma cacao* (chocolate/cocoa), also present in smaller amounts in tea (*Camellia sinensis*), cola nuts (*Cola nitida*), and yerba mate (*Ilex paraguariensis*) [Ref 30, Ref 33].
- **Chocolate content:** Dark chocolate: ~0.82–1.14 mg/g; milk chocolate: ~0.72–0.76 mg/g; white chocolate: ~0.74 mg/g (Ramli et al. 2000 [Ref 27]). Dark chocolate has higher concentrations than caffeine content by a factor of ~10–20x.
- **Historical medical use:** Used historically as a diuretic, vasodilator, and heart stimulant; largely displaced by more potent agents. Modern research interest re-emerged through cocoa/cardiovascular epidemiology (Buijsse et al. 2006 [Ref 32]).
- **Regulatory history:** No scheduling event. Recognized as a natural food constituent in all major jurisdictions.
---
## Subjective Effects
**IMPORTANT NOTE:** Theobromine has markedly weaker CNS effects than caffeine. The literature consistently characterizes it as having "little pharmacological activity" and being "almost devoid of effects on the CNS" at typical dietary doses (DrugBank/web [Ref 30]). Effects below are documented at doses studied in controlled trials.
### Controlled Human Studies
**Mitchell et al. 2011 [Ref 2] — 700 mg theobromine, 24 healthy females, crossover:**
- Theobromine (alone) decreased self-reported **calmness** at 3 hours post-ingestion on Bond-Lader visual analog scale.
- Theobromine (alone) **lowered blood pressure** relative to placebo at 1 hour.
- No treatment effect on psychomotor performance (Digit Symbol Substitution Test).
- Authors conclude theobromine may act primarily via peripheral physiological mechanisms rather than CNS-mediated alertness effects (in contrast to caffeine).
**Smit et al. 2004 [Ref 39] — chocolate vs. isolated methylxanthines:**
- Demonstrated that methylxanthines (theobromine + caffeine together) are the psycho-pharmacologically active constituents responsible for chocolate's mood effects — not phenylethylamine or anandamide as popularly claimed.
**Sumiyoshi et al. 2019 [Ref 38] — 30-day dark chocolate RCT:**
- Increased plasma theobromine correlated with enhanced cognitive function on Stroop test and digital cancellation test.
- NGF (nerve growth factor) levels increased alongside theobromine in the DC group.
- Cognitive enhancement persisted 3 weeks after chocolate consumption ended.
**Usmani et al. 2005 [Ref 1] — theobromine antitussive RCT:**
- In capsaicin cough challenge model, theobromine suppressed cough with **no adverse effects reported**.
### Effect Profile Summary (from published human studies)
Effects consistently documented:
- **Mild stimulation** (secondary to adenosine antagonism; weaker than caffeine)
- **Decreased calmness** at high doses (~700 mg) [Ref 2]
- **Blood pressure lowering** at ~700 mg, peripheral mechanism [Ref 2]
- **Antitussive effect** — peripherally mediated sensory nerve inhibition [Ref 1]
- **Heart rate changes** — possible tachycardia at very high intake (case report: ~180g/night chocolate for 2 weeks, PMID 41523427 [Ref 13])
- **Wakefulness** — mild (weaker than caffeine; adenosine A1R antagonism)
- **Diuresis** — mild (methylxanthine class effect; PDE inhibition; PGE-mediated in rats [Ref 23])
Effects NOT reliably documented in controlled human studies:
- Significant alertness/stimulation at typical dietary doses
- Mood enhancement as an isolated compound (Mitchell 2011 showed no increase in alertness, only decreased calmness)
- Anxiety or jitteriness at normal doses
### Dose-Duration Context
From controlled trials:
- 500 mg/day (4 weeks): Lipid and glucose metabolic effects; unfavorable postprandial glucose/insulin responses [Ref 17]
- 700 mg (single dose): Decreased calmness, blood pressure lowering [Ref 2]
- 850 mg (single acute): Duodenal glucose gene downregulation; adverse events begin to increase per EFSA review [Ref 34]
- 1000 mg/day: Highest adverse event rate in EFSA safety review [Ref 34]
---
## Safety & Toxicity
### Human Safety
- Theobromine is **GRAS** (Generally Recognized As Safe) as a naturally occurring food constituent. No formal ADI established [Ref 34].
- Well tolerated at typical dietary exposures (<500 mg/day from food sources).
- EFSA (2017) review: adverse events increased at 850 mg/day and were highest at 1000 mg/day [Ref 34].
- Doses of 150 mg/day in cocoa well tolerated in human studies [Ref 34].
- Unfavorable postprandial glucose and insulin responses at 500 mg/day (Smolders et al. 2018 [Ref 17]). **FLAG: Safety-critical — may be relevant for people with diabetes or insulin resistance.**
### Animal LD50 Data
- **Dogs (oral):** Approximately 100–300 mg/kg (web-retrieved [Ref 21]); toxic signs begin at 20 mg/kg, severe symptoms at 40–50 mg/kg, seizures at ~60 mg/kg.
- **Rabbits:** Approximate maternal LD50 by gavage approached 200 mg/kg in repeated-dose study (Tarka et al. 1986 [Ref 20]).
- **Rats:** NOAEL ~50 mg/kg/day in animal studies (EFSA review [Ref 34]).
- **Human LD50:** Not established. No human fatalities from theobromine alone documented in the literature reviewed.
### Species-Specific Toxicity
Dogs are markedly more sensitive to theobromine than humans due to their significantly longer half-life (~17.5 hours vs. ~10 hours in humans) [Ref 21, Ref 14]. Cats and other animals are also susceptible. Theobromine causes sinus tachycardia, muscle tremors, seizures, and cardiac arrhythmias in dogs.
### Teratogenicity
- Theobromine established as teratogenic in animal studies at high doses (York et al. 1986 [Ref 28]). Pattern of malformations similar to other methylxanthines (primarily skeletal/limb).
- Rat study (Tarka et al. 1986 [Ref 19]): Delay in osteogenesis at >50x human consumption; no significant teratogenicity at doses equivalent to human chocolate consumption.
- Rabbit study (Tarka et al. 1986 [Ref 20]): Developmental variations at 125–200 mg/kg/day gavage; no teratogenicity at dietary levels.
- **FLAG (safety-critical):** No adequate controlled human data on theobromine teratogenicity. Animal studies used doses far exceeding human exposure from food. A pregnancy RCT (Babar et al. 2018 [Ref 18]) studied high-flavanol/high-theobromine chocolate in women at preeclampsia risk, but primary focus was BP/endothelial function.
- Precautionary note: Caffeine (a structurally related compound) has established pregnancy guidance (limit 200–300 mg/day); similar caution is generally advised for theobromine during pregnancy, though specific limits are not codified in published guidelines.
### Adverse Event Profile
From human intervention studies (mostly single or 4-week doses):
- High doses (850–1000 mg/day): increased adverse event rate [Ref 34]
- 500 mg/day: unfavorable postprandial glucose/insulin [Ref 17]
- Possible GI effects at high doses
- Chocolate-induced sinus tachycardia reported in case of extreme overconsumption (~180g/night dark chocolate for 2 weeks [Ref 13])
---
## Harm Reduction
- **No specific regulatory harm reduction guidelines** for theobromine consumption in humans. Dietary intake is self-limiting through food palatability.
- For pure theobromine supplementation (available commercially): recommended doses in supplement literature are typically 100–400 mg/day. EFSA review suggests adverse events increase above 500–850 mg/day [Ref 34].
- **Drug interactions:** CYP1A2 induction (smoking, rifampin, other inducers) increases clearance ~33%; CYP1A2 inhibitors may increase theobromine plasma levels [Ref 24].
- **Cardiovascular precaution:** At high doses, potential for heart rate increases and palpitations. The chocolate sinus tachycardia case involved cumulative methylxanthine load [Ref 13].
- **Diabetes/metabolic risk:** Theobromine at 500 mg/day produced unfavorable postprandial glucose and insulin responses; caution advised in people with impaired glucose tolerance [Ref 17].
- **Veterinary hazard:** Theobromine is highly toxic to dogs and should be kept away from animals. Emergency veterinary care required if a dog consumes chocolate [Ref 21, Ref 31].
- Testing: Theobromine is readily identifiable via HPLC and LC-MS. Not subject to food testing regulations as a controlled substance.
---
## Tolerance & Dependence
### Published Evidence
- **Tolerance to PK effects:** Shively et al. (1985 [Ref 14]) directly tested whether high daily theobromine consumption (one week) altered pharmacokinetics. Result: **No change** in t1/2, Vd, or clearance. No pharmacokinetic tolerance at doses studied.
- **Metabolic tolerance:** Theobromine did not bioaccumulate in serum during gestation (Tarka 1986 [Ref 19]) and urinary metabolite profile was unchanged after one week of high intake [Ref 14].
- **Pharmacodynamic tolerance:** No published controlled studies specifically examining tolerance to theobromine's subjective or cardiovascular effects over time.
- **Dependence:** No published studies on theobromine-specific dependence or withdrawal syndrome.
- **Cross-tolerance with caffeine:** Likely given shared mechanism (adenosine receptor antagonism), but no specific human data found.
- **"Chocolate craving" / chocolate addiction:** Smit et al. (2004 [Ref 39]) demonstrated that methylxanthines (including theobromine) are the psychoactive agents in chocolate. The literature on chocolate craving attributes it primarily to the combined sensory and pharmacological properties of chocolate. No specific theobromine-driven dependence syndrome identified.
**FLAG:** Tolerance and dependence data for isolated theobromine are essentially absent from the peer-reviewed literature. Class inference from caffeine (related methylxanthine) suggests tolerance to adenosine receptor antagonism develops with regular use, but this has not been studied for theobromine specifically.
---
## Interactions
### Published Drug Interaction Data
**CYP1A2 interactions:**
- CYP1A2 contributes partially to theobromine metabolism (N7-demethylation to 7-MX) [Ref 24].
- **Smoking/enzyme inducers:** Cigarette smoking increases theobromine plasma clearance by ~33%, likely via CYP1A2 induction [Ref 24]. Similar effects expected from rifampicin, phenytoin, and other CYP1A2 inducers.
- **CYP1A2 inhibitors** (e.g., fluvoxamine, ciprofloxacin): Would be expected to decrease theobromine clearance, potentially increasing plasma levels. No specific published data for theobromine-drug interaction studies.
- **CYP2E1 involvement** also identified [Ref 24]; CYP2E1 inducers (e.g., ethanol, isoniazid) may also affect metabolism.
**Additive methylxanthine effects:**
- Mitchell et al. (2011 [Ref 2]): Caffeine + theobromine combination showed caffeine-like effects on alertness with no additional effect on blood pressure. The combination did not produce synergistic CNS effects beyond caffeine alone.
**Theobromine-flavanol interaction:**
- Theobromine significantly increases flavan-3-ol bioavailability when co-ingested with cocoa (+21% Cmax in subjects with functional colon) through colonic mechanisms [Ref 36]. This has implications for health effect attributions from whole chocolate consumption.
**MAOIs and serotonergic drugs:**
- No published human data on theobromine + MAOI interactions found. The tyramine content in chocolate (not theobromine per se) is the primary concern with MAOI use.
**FLAG (safety-critical):** Specific theobromine drug interaction studies are essentially absent from the literature. Interactions are largely inferred from class data (methylxanthines) and metabolic enzyme involvement. Any co-administration with potent CYP1A2 inhibitors or inducers should be flagged as potentially clinically relevant.
---
## Legal Status
Based on web search research:
| Jurisdiction | Status | Notes |
|---|---|---|
| United States | Unscheduled | Food ingredient; available as dietary supplement; not DEA-scheduled |
| United Kingdom | Unscheduled | Food ingredient; sold freely |
| European Union | Unscheduled | Food ingredient; EFSA has reviewed safety as flavouring [Ref 34] |
| Canada | Unscheduled | Food ingredient |
| Australia | Unscheduled | Food ingredient; available OTC |
| International | Unscheduled | Not listed in any UN Convention schedules |
Theobromine has never been subject to scheduling proceedings in any major jurisdiction. Its presence in universally consumed foods (chocolate, tea, cocoa) places it outside controlled substance frameworks. No analog act applicability.
---
## Clinical Trials
**Dedicated theobromine-specific trials:** No trials with theobromine as the primary intervention were found on ClinicalTrials.gov via the searches conducted (searched "theobromine" and "theobromine cocoa methylxanthine cough blood pressure cognitive").
**Trials identified with theobromine as an explicit component of study design:**
1. **NCT03526107** (Ottaviani/Schroeter group, completed) — Flavan-3-ol-methylxanthine interactions study part 1; volunteers with functional colon [Ref 36].
2. **NCT03765606** (Ottaviani/Schroeter group, completed) — Flavan-3-ol-methylxanthine interactions study part 2; ileostomists [Ref 36].
3. **IRCT20091114002709N59** (Sharifi-Zahabi et al. 2023, completed) — 12-week pure theobromine supplementation (450 mg/day) + low-calorie diet in metabolic syndrome; registered in Iran [Ref 3].
**Relevant cocoa/chocolate RCTs in which theobromine was measured:**
- NCT03452605 — Effect of cocoa flavanol on BOLD response and cognitive function in Type 1 diabetes (completed).
**Summary:** No large Phase 2/3 clinical trials specifically studying theobromine as a pharmaceutical agent are currently registered or completed in ClinicalTrials.gov. Existing human evidence comes from academic nutrition research trials (typically 8–80 participants, 1 day to 12 weeks).
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## Gaps & Flags
### Data Absent from Published Literature
1. **Binding affinity Ki values at adenosine receptor subtypes:** No primary PubMed literature returned Ki or Kd values for theobromine at human A1R or A2AR. Best available evidence is functional electrophysiology (Valada 2022 [Ref 15]) and reports of IC50 >1000 µM at A2A from historical pharmacological characterization (web-retrieved context). **Generation agent should note this absence explicitly.**
2. **Dose-response for subjective psychoactive effects:** Only one primary controlled study (Mitchell 2011 [Ref 2], 700 mg single dose, 24 women) has isolated theobromine's subjective effects. No dose-ranging study exists. Effects at lower doses (100–300 mg — the typical supplementation range) are not characterized in isolation.
3. **Tolerance and dependence data:** No published studies on pharmacodynamic tolerance, physical dependence, or withdrawal syndrome for theobromine as an isolated compound. Class inference from caffeine is the only available framework.
4. **Human LD50:** Not established. Animal data suggests wide safety margin at human dietary exposures.
5. **Duration of effects from single doses:** No controlled studies specifically measuring onset, peak, and offset of theobromine's subjective effects with standard psychometric tools.
6. **Detailed ROA data:** Only oral administration has been studied in humans. No data on intranasal, IV, or other routes.
7. **SMILES string in seed data was missing:** Confirmed: Cn1cnc2c1c(=O)[nH]c(=O)n2C (from PubChem).
### Safety-Critical Flags
- **Postprandial glucose/insulin:** Theobromine 500 mg/day produced unfavorable postprandial glucose and insulin responses in one RCT (Smolders 2018 [Ref 17]). Clinical significance for diabetic individuals is unknown. **Should be flagged in contraindications.**
- **Pregnancy:** Animal teratogenicity data exists at supraphysiological doses. No human teratogenicity data. **Precautionary guidance warranted; generation agent should not make definitive safety-in-pregnancy statements.**
- **CYP drug interactions:** CYP1A2 partial involvement means drug interactions are theoretically possible, but no clinical drug interaction studies exist for theobromine. **Safety-critical gap.**
- **High-dose adverse events:** EFSA review found increased adverse events at 850–1000 mg/day. However, the specific nature of these adverse events is not fully described in the retrieved literature. **Generation agent should not specify adverse event types beyond what is documented.**
### Contradictions / Discrepancies
- **Half-life discrepancy:** Shively et al. 1985 [Ref 14] reports t1/2 ~10 hours; DrugBank and other secondary sources report 6–8 hours. Shively is the primary human PK study and should be treated as more authoritative. The discrepancy may reflect different subject populations, methylxanthine pre-exposure status, or analytical methods.
- **Lipid effects:** Some RCTs show HDL improvement (Neufingerl 2013 [Ref 16]; Sharifi-Zahabi 2023 [Ref 3]); others show no effect on HDL (Jacobs 2017 [Ref 25]; Smolders 2019 [Ref 5]). The systematic review (Sharifi-Zahabi 2023 [Ref 4]) notes findings are "equivocal" and population-dependent. **Generation agent should present both sides without resolution.**
- **Blood pressure effects:** Mitchell 2011 [Ref 2] found BP-lowering at 700 mg single dose; Sharifi-Zahabi 2023 [Ref 3] found no significant BP effect at 450 mg/day for 12 weeks. Different populations and dosing regimens may explain the discrepancy.