Bufotenin

# Research Output: Bufotenin

**PSX ID:** PSX-0121  
**Research Date:** 2026-04-26  
**Generation Provenance ID:** eade0dc2-ba2a-44ff-b73f-27006586a371

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## Chemical Identity

**Confirmed via PubChem CID 10257:**

| Property | Value | Source |
|---|---|---|
| PubChem CID | 10257 | PubChem API |
| IUPAC Name | 3-[2-(dimethylamino)ethyl]-1H-indol-5-ol | PubChem API |
| Systematic Name | 5-hydroxy-N,N-dimethyltryptamine (5-HO-DMT) | PubChem |
| Molecular Formula | C12H16N2O | PubChem API |
| Molecular Weight | 204.27 g/mol | PubChem API |
| InChIKey | VTTONGPRPXSUTJ-UHFFFAOYSA-N | PubChem API |
| CAS Number | 487-93-4 | Web-retrieved [Ref 29, Ref 31] |
| SMILES (canonical) | CN(C)CCc1c[nH]c2cc(O)ccc12 | Derived from IUPAC/InChIKey — not directly returned by PubChem API |
| DEA Drug Code | 7403 | Web-retrieved [Ref 28, Ref 29] |

**Other names:** N,N-dimethylserotonin, mappine, dimethylserotonin, bufotenine (alternate spelling)

**Note on SMILES:** The PubChem E-utilities API returned formula, weight, IUPAC name, and InChIKey but not SMILES directly in this research run. The canonical SMILES CN(C)CCc1c[nH]c2cc(O)ccc12 is universally accepted in the literature and consistent with the IUPAC name and InChIKey; the generation agent should confirm via PubChem web interface.

**Brief seed data match:** Molecular formula C12H16N2O ✓, MW 204.27 ✓, IUPAC name ✓. PubChem CID was absent from seed data — now confirmed as **10257**. InChIKey confirmed as VTTONGPRPXSUTJ-UHFFFAOYSA-N (absent from seed data).

**Physical properties (web-retrieved [Ref 28]):**
- Log P (lipophilicity): 0.89–2.04 (varies by calculation method) — relatively hydrophilic
- Melting point: Not confirmed by API-verified primary source. **FLAG for editorial: melting point not found in peer-reviewed literature accessed.**
- Solubility: Not quantified in API-accessible literature. Described as relatively hydrophilic, which limits BBB penetration [Ref 2, Ref 19, Ref 28]

**Structural context:** Bufotenin is the 5-hydroxy (5-OH) analogue of DMT and the N,N-dimethyl analogue of serotonin. It is structurally isomeric with psilocin (4-HO-DMT), which differs only in the position of the hydroxyl group on the indole ring [Ref 6].

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## Pharmacology

### Receptor Binding Profile

Quantitative binding affinities (Ki values) for bufotenin compiled from multiple sources [Ref 28]:

| Receptor | Ki (nM) | EC50 (nM) | Notes |
|---|---|---|---|
| 5-HT1A | 2.5–1,023 | 13–766 | Agonist; range across studies |
| 5-HT2A | 15–>10,000 | 3.5–232 | Partial agonist/low efficacy (see below) |
| 5-HT2C | 16–209 | 2.3–182 | Agonist; functional selectivity reported |
| 5-HT1D | 3.7–29 | 0.66–2.6 | Agonist |
| 5-HT3 | 34–210 | ND | Receptor binding confirmed [Ref 15] |
| 5-HT4 | pD2 = 6.77–7.04 | — | Agonist in human cardiac tissue (see below) |
| SERT | ~1,120 | ~1,200 (IC50) | Weak uptake inhibition |

**⚠ FLAG:** Ki values show large ranges across studies, indicating variability in assay conditions and binding preparations. The generation agent should note this uncertainty.

### 5-HT2A: Binding vs. Efficacy Dissociation

Bufotenin presents an important pharmacological paradox: it binds the 5-HT2A receptor but demonstrates very low or absent functional efficacy. Roth et al. (1997) showed that bufotenine labeled only ~22% of high-affinity 5-HT2A agonist binding sites (vs. 26% for a full agonist DOI) but was **devoid of detectable agonist activity** in phosphoinositide hydrolysis assays [Ref 7]. This dissociation between binding and second-messenger production is consistent with a modified ternary complex model where receptor activation requires additional transition states beyond high-affinity binding.

The molecular basis was clarified by Almaula et al. (1996): the N,N-dimethylation of bufotenin causes steric hindrance preventing a key hydrogen bond with Ser3.36(159) in transmembrane helix 3 of the 5-HT2A receptor [Ref 8]. Unlike serotonin's primary amine, bufotenin's tertiary amine interacts with Asp3.32 but not Ser3.36, altering its orientation in the binding pocket and reducing efficacy. Ebersole et al. (2003) confirmed that agonist position in the binding pocket determines degree of receptor activation [Ref 32].

### 5-HT2C: Functional Selectivity

At the 5-HT2C receptor, bufotenin exhibits **agonist-directed trafficking**: its efficacy order for arachidonic acid (AA) release vs. inositol phosphate (IP) accumulation is reversed compared to TFMPP. Berg et al. (2001) demonstrated this functional selectivity at the non-edited 5-HT2C receptor, and showed that RNA editing of the second intracellular loop eliminates this biased trafficking [Ref 9]. This has implications for understanding bufotenin's behavioral effects.

### 5-HT1A: The Suppression Problem

Bufotenin is also an agonist at 5-HT1A receptors (Ki 2.5–1,023 nM), and this dual activity is critical for understanding its psychedelic profile. Maitland et al. (2025) — a preprint — directly tested bufotenin in the mouse head twitch response (HTR) paradigm, the standard behavioral proxy for 5-HT2A-mediated psychedelic effects [Ref 23]. Key finding: **bufotenine only produced elevated HTRs when 5-HT1A receptors were pharmacologically blocked** (ED50 = 0.99 mg/kg, max counts = 24). Without 5-HT1A blockade, bufotenine showed no significant HTR activity. This directly demonstrates that bufotenin's 5-HT1A agonism actively suppresses its potential psychedelic (5-HT2A-mediated) effects, paralleling findings with 5-MeO-DMT analogs (Glatfelter et al. 2024 [Ref 27]).

**⚠ FLAG (preprint):** Maitland 2025 is a preprint (bioRxiv); peer review not yet completed. This is the most current direct behavioral pharmacology data on bufotenin and should be cited with appropriate caveat.

### 5-HT4: Cardiovascular Agonism

Neumann et al. (2023) provided the first direct demonstration of bufotenin as an agonist at **human 5-HT4 receptors** in cardiac tissue [Ref 11]:
- Positive inotropic effect: pD2 = 6.77 in left atrial preparations
- Positive chronotropic effect: pD2 = 7.04 in spontaneously beating right atrial preparations
- Effects confirmed in isolated human atrial preparations (musculi pectinati)
- Effects blocked by tropisetron (5-HT3/4 antagonist)
- Potentiated by MAO inhibitor pargyline
- Phospholamban phosphorylation increased, consistent with cAMP-mediated cardiac pathway

This 5-HT4 agonism is clinically significant: it provides a mechanism for the cardiovascular effects (tachycardia, increased blood pressure, flushing) historically observed in human experiments and by users.

### Additional Receptor Interactions

- **Sigma-1 receptor:** Binding implicated by reverse docking analysis (Wang 2021 [Ref 15]); may contribute to anti-inflammatory effects
- **5-HT3A receptor:** Binding implicated in anti-inflammatory pathway (Wang 2021 [Ref 15])
- **AChE and α4β2 nAChR:** Reverse docking identified these as analgesic targets (Zhao 2021 [Ref 14])
- **SERT:** Weak inhibitor (Ki ~1,120 nM); weaker than serotonin itself

### Mechanism of Action (Summary)

Bufotenin acts as a serotonin receptor agonist across multiple subtypes, but its psychedelic profile is significantly constrained by two factors:
1. **Poor BBB penetration** (see Pharmacokinetics) limits CNS access via peripheral routes
2. **Balanced 5-HT1A/5-HT2A agonism** — the 5-HT1A component actively suppresses psychedelic (5-HT2A-mediated) effects

Bradley & Briggs (1974) demonstrated in rat brainstem microiontophoresis that bufotenine, like DMT and 5-MeO-DMT, antagonized 5-HT excitations on single neurons, providing early neurophysiological evidence of CNS activity when administered directly [Ref 10]. McBride (2000) reviewed the overall evidence and concluded that the reported lack of classic hallucinogenic response in human IV experiments is attributable to poor BBB penetration rather than failure to activate relevant receptors [Ref 1].

### Pharmacokinetics

**Animal data (rats, [Ref 2]):**
- Peak tissue concentration: ~1 hour post-SC injection
- Distribution: High in lung, heart, blood; significantly lower in brain and liver
- Brain penetration: Poor — concentrations 15-fold lower brain:blood ratio vs. 5-MeO-DMT [Ref 28]
- Elimination: Nearly complete by 8 hours
- Primary metabolite: 5-hydroxyindoleacetic acid (5-HIAA; ~70% of dose) — identical to the serotonin metabolite
- N-oxide: Bufotenin N-oxide also detected as metabolite [Ref 35]
- Unchanged excretion: ~4% eliminated unchanged
- MAO-A metabolism: Primary metabolic enzyme is MAO-A (not MAO-B); confirmed by Fuller et al. using selective inhibitors LY51641 (MAO-A selective) vs. deprenyl (MAO-B selective) [Ref 2]
- Platelet storage: Unlike serotonin, bufotenin is NOT stored in platelets (>99% found in platelet-poor plasma vs. 2% for serotonin) [Ref 2]

**Membrane modeling (Zohairi et al. 2023 [Ref 19]):**
- Molecular dynamics simulations confirm bufotenine partitions into lipid bilayers but does NOT cross the membrane spontaneously during simulation time — unlike DMT and 5-MeO-DMT, which cross spontaneously
- Bufotenine has the maximum effect on membrane structural properties among the three tryptamines tested
- This directly models the molecular basis of its poor CNS penetration via systemic routes

**Human PK:** No published controlled human pharmacokinetic studies identified. Historical human IV experiments documented physiological effects but no plasma concentration measurements found in API-accessible literature. **FLAG: Human PK data absent from published literature.**

**Smoked route:** The primary ROA in the database is smoked. Published human PK data for smoked bufotenin is absent from peer-reviewed literature. The rapid onset (15–30 seconds) and short duration (15–90 minutes total) in the seed data are consistent with the kinetics of smoked tryptamines but are unverified by controlled studies for bufotenin specifically.

**Endogenous production:** Bufotenin is produced endogenously in humans and is normally detectable in urine. MAO-A presumably keeps endogenous levels low under normal circumstances [Ref 1, Ref 4, Ref 17].

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## History

### Discovery and Chemistry

**1893:** Bufotenin (as an unnamed toxic component) was first isolated from the cutaneous secretion of Bufo vulgaris (common toad) by French pharmacologist Césaire Phisalix and Gabriel Bertrand [Ref 30, Ref 5]. The chemical identity of the isolated compound was not established at this time.

**~1920:** Austrian chemist Hans Handovsky (University of Prague) isolated the compound from Bufo vulgaris, characterized it more fully, and named it "bufotenin" (from Bufo, the toad genus) [Ref 5]. This naming is generally credited as establishing bufotenin as a distinct compound, though the chemical structure was not yet determined.

**1934:** German chemist Heinrich Wieland and colleagues confirmed the chemical structure of bufotenin, establishing it as 5-hydroxy-N,N-dimethyltryptamine — a dimethylated derivative of serotonin with a 5-hydroxyl group on the indole ring [Ref 30].

**1935:** First total synthesis of bufotenin achieved by Japanese researchers [Ref 28].

**Pre-1950 context:** Serotonin (5-hydroxytryptamine) was not isolated from peripheral tissues until 1948 (Rapport, Green & Page). The structural identity of bufotenin as N,N-dimethylserotonin was thus retroactively meaningful — bufotenin was recognized as a naturally occurring N,N-methylated derivative of a key neurotransmitter.

### Natural Sources and Indigenous Use

**Plant sources:** Bufotenin is a major alkaloid in seeds of *Anadenanthera peregrina* (formerly *Piptadenia peregrina*), native to South America and the West Indies [Ref 6]. These seeds are the primary component of traditional hallucinogenic snuffs:
- *Yopo/Cohoba*: Snuff prepared from Anadenanthera seeds; used in ritual contexts by indigenous peoples of South America and the Caribbean
- Archaeological evidence: Bufotenin has been identified in 1,200-year-old archaeological samples of Anadenanthera material found in excavated tombs in Northern Chile [Ref 6]
- Historical records: Spanish colonizers documented cohoba snuff use for ritual divination by Taíno people in the 15th–16th century

**Toad sources:** Chen et al. (2023) identified the biosynthetic enzyme responsible for bufotenin production in toads: a novel indolethylamine N-methyltransferase (RmNMT) in the cane toad *Rhinella marina* and a related NMT in *Bufo bufo* [Ref 12]. Close homologs in frog species were inactive, suggesting toad-specific evolution of this pathway. The enzyme converts primary indolethylamines (e.g., serotonin) to tertiary methylated forms (including bufotenin). Bufotenin is found in the skin and parotid glands of: *B. marinus*, *B. vulgaris*, *B. viridis*, *Rhinella marina* [Ref 6, Ref 12].

**Fungal sources:** Bufotenin has been reported in *Amanita muscaria*, *A. citrina*, *A. porphyria*, and *A. tomentella* mushrooms [Ref 6]. **FLAG:** The presence and pharmacological significance of bufotenin in *Amanita muscaria* specifically has been disputed in the literature. The psychoactive effects of A. muscaria are primarily attributed to ibotenic acid and muscimol, not bufotenin. This warrants editorial note.

**Plant (non-Anadenanthera):** Bufotenin isolated from *Desmodium elegans* leaves (Zhi et al. 2014 [Ref 34]).

**Endogenous human production:** Bufotenin is detectable in human urine and is presumed to be produced endogenously, likely via the same INMT (indolethylamine N-methyltransferase) enzyme that produces DMT [Ref 4, Ref 17].

### Human Experimental History

**1956:** Fabing and Hawkins conducted one of the first documented human experiments with IV bufotenin in psychiatric patients. **⚠ FLAG:** This citation is pre-PubMed and could not be retrieved or verified via API tools. Lyttle et al. (1996) [Ref 5] review this work extensively. Effects reported included prominent cardiovascular effects (facial flushing, tachycardia, hypertension) and some visual phenomena at higher doses.

**1959:** Turner and Merlis administered IV bufotenin to psychiatric patients. **⚠ FLAG:** Same caveat — pre-PubMed, not API-accessible. Again reviewed in Lyttle 1996 [Ref 5]. Classic psychedelic hallucinations were absent or equivocal; peripheral/cardiovascular effects dominated. This contributed to the long-standing scientific debate about whether bufotenin is truly hallucinogenic.

**1990s:** Bufotenin was identified in 42 case samples seized by the New York City Police Laboratory (1992 onward), sold on streets as hard, dark reddish-brown resinous material described as "hashish" and smoked in combination with marijuana [Ref 6]. Material likely derived from Anadenanthera seeds. This represented the first documented street use of bufotenin outside its traditional South American context.

### Regulatory History

Bufotenin was placed under Schedule I control in the United States under the Controlled Substances Act [Ref 28, Ref 29]. The exact date of federal scheduling is not confirmed by API-accessible sources. Illinois state scheduling became effective February 2, 1996 [Ref 31].

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## Subjective Effects

**Published controlled human study data:** No modern controlled studies with standardized dosing and systematic subjective effect measurement identified in API-accessible literature. The absence of published human psychopharmacology data is a major gap.

**Historical human IV experiments (1950s–60s; unverifiable primary sources; reviewed in [Ref 1, Ref 5]):**
- Prominent peripheral effects: facial flushing/erythema, increased heart rate, elevated blood pressure, difficulty breathing, nausea
- Visual disturbances at high doses (reported variously as colored patterns, visual changes)
- Equivocal hallucinogenic response: Some studies reported no clear psychedelic effects; others reported mild alterations
- McBride (2000) attributes the poor psychedelic response to BBB impermeability rather than absence of relevant receptor activity [Ref 1]

**User reports (Chamakura 1994 forensic context [Ref 6]; Lyttle 1996 review [Ref 5]; non-peer-reviewed):**
- Smoked route: Reportedly produces psychedelic effects including visual phenomena, body sensations, brief altered state
- Typically mixed with plant material (Anadenanthera seeds or smoked with cannabis)
- Short duration consistent with other smoked tryptamines

**Effect taxonomy from seed data (no published controlled source identified; user-report-level evidence):**
The following effect domains are listed in the Psychedex database but are currently supported primarily by user-report-level evidence, not controlled clinical data:
- Perception: Vestibular distortion, visual drifting, color alteration, visual recursion, environmental orbism/cubism, music enhancement, visual acuity enhancement
- Feeling: Euphoria, emotional enhancement, anxiety
- Body: Bodily heaviness, vasoconstriction, nausea, motor control impairment, pupil dilation, temperature dysregulation, bodily pressures, spontaneous body sensations
- Thinking: Thought connectivity, conceptual thinking, analysis enhancement, delusions, amnesia, memory suppression
- Transpersonal: Entity contact, unity and interconnectedness
- Awareness: Mindfulness enhancement

**Cardiovascular effects specifically** are supported by the animal literature [Ref 2] and Neumann et al. 2023 human cardiac tissue data [Ref 11] — vasoconstriction and increased cardiac output via 5-HT4 and peripheral serotonin receptors are well-evidenced mechanisms.

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## Safety & Toxicity

### LD50 / Lethal Dose

**Published LD50 in humans:** None found. The seed data states "toxic dose is unknown" — confirmed.

**Animal data:** Fuller et al. (1995) used doses up to 100 mg/kg SC in rats without reporting lethality, though this was not a toxicity study [Ref 2]. No published LD50 data found in API-accessible literature.

### Cardiovascular Risk

The most clearly documented safety concern for bufotenin is cardiovascular toxicity, mediated via multiple serotonin receptor subtypes:

1. **5-HT4-mediated cardiac effects (human tissue confirmed):** Neumann et al. (2023) demonstrated bufotenin increases cardiac contractility and heart rate via 5-HT4 receptors in human atrial preparations [Ref 11]. Effects were potentiated by MAO inhibition. This is clinically significant as MAOIs are common co-exposures in traditional ayahuasca contexts and potential street drug combinations.

2. **Peripheral vasoconstriction:** Long recognized as a major effect — particularly after systemic administration. The Britannica entry notes bufotenine is "a powerful constrictor of blood vessels, causing a rise in blood pressure" [Ref 30].

3. **Historical adverse events:** Human IV experiments in the 1950s frequently produced alarming cardiovascular effects — facial flushing, tachycardia, hypertension — at doses attempting to produce psychedelic effects [Ref 1, Ref 5]. Some researchers considered these adverse effects prohibitive.

### Respiratory

Some historical reports describe difficulty breathing/respiratory distress after systemic bufotenin administration. Mechanism unclear — possible 5-HT3 or 5-HT4 involvement in pulmonary vasculature, or anxiety response [Ref 1].

### Psychological Risk

**Delusions and psychosis-adjacent states:** The transmethylation hypothesis (Ciprian-Ollivier 1997 [Ref 17]; Clarke 2025 [Ref 4]) proposes that endogenous overproduction of bufotenin may contribute to psychotic symptoms. Whether exogenous administration can reliably induce frank psychosis is uncertain — published data is insufficient.

**Anxiety:** Listed in the seed data effects taxonomy; consistent with serotonergic activation.

### Organ Toxicity

No published organ toxicity studies specific to bufotenin identified in API-accessible literature.

### Stress Response

Fuller et al. (1995) found that bufotenin injection increased serum corticosterone in rats (indicating HPA axis stress response) [Ref 2]. This effect was not blocked by metergoline at a dose that blocked quipazine-induced corticosterone elevation, suggesting the mechanism may differ from typical serotonergic HPA stimulation.

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## Harm Reduction

### Route-Specific Risks

**Smoked (primary ROA per database):** Avoids first-pass MAO metabolism; potentially allows more bufotenin to reach circulation. Onset very rapid (15–30 seconds per seed data). Risk of cardiovascular spike (tachycardia, hypertension) particularly in people with cardiac conditions.

**Intravenous (historical experimental route):** Produced alarming cardiovascular effects in 1950s–60s experiments. Not a recommended recreational route.

**Oral:** Extensive first-pass MAO metabolism renders bufotenin largely inactive orally unless combined with MAO inhibitors [Ref 28]. MAOI combination creates serious serotonin syndrome risk (see Interactions below).

### Contraindications

**⚠ SAFETY FLAG:** The following contraindications are inferred from pharmacological data rather than published clinical guidelines specific to bufotenin. No published clinical contraindication protocols for bufotenin found in API-accessible literature.

- **Cardiovascular disease, hypertension, arrhythmia:** Given 5-HT4-mediated positive inotropy and chronotropy in human cardiac tissue [Ref 11] and peripheral vasoconstriction, cardiovascular risk is substantial
- **MAOI use:** Combination with MAO inhibitors will prevent bufotenin metabolism, dramatically increasing plasma levels and duration of action; serotonin syndrome risk elevated
- **Serotonergic drugs:** Additive serotonergic load
- **Tramadol:** See Interactions section

### Testing

Bufotenin can be identified by:
- Color tests (qualitative)
- TLC (thin-layer chromatography)
- GC/MS: Bufotenin and psilocin have very similar mass spectra but different GC retention times [Ref 6]
- Anadenanthera seed material may also contain DMT and other tryptamines [Ref 6]

---

## Tolerance & Dependence

### Seed Data Assessment

**Tolerance:**
- Buildup: "almost immediately after ingestion" (seed data)
- Half-life: 1 hour (seed data)
- Full reset: 2 hours (seed data)

These values are very short and consistent with other short-acting tryptamines (e.g., DMT). **FLAG:** No primary published source found to specifically confirm or refute these bufotenin-specific tolerance parameters. Values may be extrapolated from DMT or 5-MeO-DMT class behavior. Structural analog inference should be noted.

**Dependence:** Seed data states "not habit-forming." This is consistent with the general class-level observation that serotonergic psychedelics have low abuse potential and no recognized physical dependence profile. No published dependence liability studies specific to bufotenin found.

### Cross-Tolerance

No published cross-tolerance data specific to bufotenin found. Class inference: likely to show cross-tolerance with other serotonergic psychedelics (psilocin, DMT, LSD) via shared 5-HT2A and 5-HT1A receptor downregulation, but this is not confirmed by bufotenin-specific data.

---

## Interactions

### Tramadol (Database: Dangerous)

The database lists tramadol as a **dangerous** interaction. This is mechanistically well-supported though not directly tested in bufotenin-specific published studies:

1. **Tramadol** is a weak serotonin reuptake inhibitor (SRI) and has been implicated in serotonin toxicity when combined with MAOIs, including fatalities (Gillman 2005 [Ref 25]; Schenk & Wirz 2015 [Ref 26])
2. **Bufotenin** is:
   - A direct serotonin receptor agonist (5-HT1A, 5-HT2A/C, 5-HT4) — increases serotonin receptor activation
   - Metabolized by MAO-A (Fuller 1995 [Ref 2]) — tramadol's SRI activity would reduce serotonin breakdown indirectly
   - Combined, the two compounds create a dual serotonergic load: direct receptor agonism (bufotenin) + increased synaptic serotonin (tramadol's SRI effect)

**Mechanism conclusion:** Combination of tramadol + bufotenin creates risk of serotonin syndrome via complementary mechanisms — direct receptor agonism plus SRI activity. The "dangerous" rating in the database is mechanistically justified.

**[Community feedback: No specific community feedback submitted on this interaction]**

### Cannabis (Database: Unknown)

No published pharmacokinetic or pharmacodynamic interaction data between cannabis and bufotenin found. The database "unknown" rating is appropriate given absence of data. Historically, Chamakura (1994) noted that NYC street bufotenin was typically smoked in combination with marijuana [Ref 6], suggesting co-use occurs, but no safety data on this combination exists.

### MAO Inhibitors

Not explicitly listed in seed data interactions, but represents a critical pharmacological consideration. MAO-A inhibition (e.g., harmaline, moclobemide, phenelzine) will dramatically prolong and intensify bufotenin effects by blocking its primary metabolic pathway [Ref 2, Ref 25]. High serotonin syndrome risk. Historical Anadenanthera snuff preparations may have contained beta-carboline MAO inhibitors from co-administered plants.

### SSRIs/SNRIs

Not listed in seed data but pharmacologically relevant — serotonin receptor downregulation from chronic SSRI use may blunt bufotenin effects; acute co-administration adds serotonergic load. No published data specific to bufotenin.

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## Legal Status

| Jurisdiction | Status | Notes |
|---|---|---|
| United States | Schedule I | DEA Drug Code 7403; hallucinogen classification [Ref 28, Ref 29] |
| Illinois (US state) | Schedule I | Effective February 2, 1996 [Ref 31] |
| United Kingdom | Class A, Schedule I | Under the Misuse of Drugs Act 1971 [Ref 28, Ref 29] |
| Australia | Schedule 9 (Prohibited Substance) | Poisons Standard; 6g triggers trial, 2g indicates intent to supply [Ref 28] |
| New Zealand | Class A | Most restrictive category [Ref 29] |
| South Africa | Undesirable Dependence-Producing Substance | Listed under Drug and Drug Trafficking Act No. 140 of 1992 [Ref 29] |
| Canada | Not explicitly scheduled | As of 2025 [Ref 28] |
| Sweden | Suggested hazardous substance | Classification suggested May 2019 [Ref 28] |

**FLAG:** EU member state-specific legal status (Germany, Netherlands, France, etc.) not confirmed by API-accessible sources. The UK classification is post-Brexit and likely unchanged from the Misuse of Drugs Act 1971 scheduling. Generation agent should note this gap.

**Analog Act:** Bufotenin is explicitly named as a Schedule I substance in the US (not merely covered by analog act provisions), as evidenced by its specific DEA Drug Code 7403.

---

## Clinical Trials

**No clinical trials specifically studying bufotenin identified** via ClinicalTrials.gov search. The search returned trials for 5-MeO-DMT (GH001 by GH Research Ireland Limited), which is a related but distinct compound present in toad secretion alongside bufotenin. Bufotenin has not progressed to clinical trial stage as of 2026.

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## Community Feedback Analysis

**No community feedback submitted.** (Part A2 of the brief was empty.)

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## Gaps & Flags

### Critical Gaps

1. **No published human pharmacokinetic data** — No plasma concentration measurements, bioavailability data, or Tmax/Cmax data for any route of administration in humans. All PK data is from rats (Fuller 1995 [Ref 2]).

2. **No controlled human psychopharmacology studies** — The historical 1950s–60s experiments (Fabing & Hawkins 1956; Turner & Merlis 1959) are pre-PubMed and could not be retrieved or verified via API. These are the only documented human dosing data, and they used IV administration. No modern controlled study exists.

3. **No published LD50 in any species for comparison** — Toxic dose truly unknown; cannot calculate therapeutic index.

4. **SMILES not directly returned by PubChem API** — Derived from IUPAC name/InChIKey. Generation agent should verify against PubChem web entry for CID 10257.

5. **Melting point and solubility not confirmed by primary API-accessible source** — Physical property gap.

6. **Smoked route pharmacokinetics entirely absent from published literature** — The primary ROA in the database (smoked) has no pharmacokinetic validation. Dose and duration values in seed data are consistent with class-level expectations but unverified for bufotenine specifically.

7. **Gonçalves de Lima's work** (reportedly the first to propose bufotenin as the active component in Anadenanthera snuff, ~1946) is referenced in secondary literature but not accessible via APIs. Primary source could not be verified.

### Safety-Critical Flags

8. **⚠ Tramadol interaction rated "dangerous"** — Mechanistically well-supported (see Interactions section) but no bufotenin-specific published data exists confirming this interaction. Mechanism basis: tramadol is a weak SRI [Ref 25, Ref 26]; bufotenin is MAO-A substrate and direct serotonin agonist [Ref 2]. Combination creates dual serotonergic load with serotonin syndrome potential. Rating appears appropriate but is an inference, not a documented case.

9. **⚠ 5-HT4 cardiac agonism confirmed in human tissue [Ref 11]** — The cardiovascular safety implications are substantial. Bufotenin demonstrated positive inotropic and chronotropic effects in human atrial preparations. This is not reflected in the current contraindications field in the seed data. **RECOMMEND: Add cardiovascular disease / cardiac arrhythmia as contraindication.**

10. **⚠ Maitland et al. 2025 is a preprint** [Ref 23] — The HTR data showing bufotenine requires 5-HT1A blockade for psychedelic activity is the most current behavioral pharmacology, but peer review is pending.

### Contradictions with Seed Data

11. **Psychoactive class listed as "Psychedelic"** — The published evidence suggests bufotenin's psychedelic activity is substantially constrained by: (a) poor BBB penetration via standard routes, and (b) 5-HT1A agonism suppressing 5-HT2A effects. Mouse data (Maitland 2025 [Ref 23]) shows psychedelic-like effects only with 5-HT1A blockade. The smoked route may overcome BBB issues, but 5-HT1A suppression remains. This does not mean it is not psychedelic — it means the conditions under which psychedelic effects manifest are pharmacologically constrained. The generation agent should present this nuance.

12. **"Emerging" characterization in seed data** — This characterization may be outdated. Bufotenin has been known and studied since 1893, with human experiments in the 1950s and street drug identification in the 1990s. However, modern research (post-2020) on its pharmacology is indeed limited. The "emerging" label may reflect limited recent clinical/research attention rather than novelty of the compound.

### Structural Analog / Class Inference

13. **Tolerance parameters (buildup: "almost immediately"; half-life: 1h; full reset: 2h)** — No bufotenin-specific published source found. These values appear extrapolated from DMT or 5-MeO-DMT. Struct analog inference — should be flagged in article.

14. **Cross-tolerance data** — Absent from published literature; class inference from other serotonergic psychedelics.

15. **Cannabis interaction listed as "unknown"** — Appropriate; no data exists.