βk-2C-B
β-keto-4-bromo-2,5-dimethoxyphenethylamine
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βk-2C-B (beta-keto 2C-B) is a synthetic stimulant-psychedelic of the substituted cathinone and phenethylamine classes. It is a structural variant of 2C-B that requires far higher doses and lasts nearly twice as long. It blocks dopamine and norepinephrine reabsorption and activates serotonin receptors, producing stimulation alongside psychedelic perceptual shifts.
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LSD, psilocybin, mescaline +2 moreLSD, psilocybin, mescaline, DOx series, 2C-x series show less
First discussed on an internet forum in December 2007, βk-2C-B attracted little attention until research chemical vendors began selling it around 2013–2014 as a legal substitute for 2C-B. The first scientific characterization came in 2015.[1] It remains unscheduled in most jurisdictions and circulates in small quantities on research chemical markets.
Subjective effects include geometric visual patterns, physical euphoria, empathogenic warmth, stimulation, and pronounced body load. The experience blends a sustained stimulant foundation with psychedelic perceptual shifts and social openness — closer in character to mescaline-type compounds than to psilocybin or LSD.[2] Nausea, anxiety, and heavy body load are common, particularly at higher doses.[3]
βk-2C-B is not considered habit-forming, but the toxic and lethal doses are unknown. It combines cardiovascular stimulation from the cathinone component with serotonergic psychedelic load — one unverified report describes cardiac arrest following use,[3] and smoking it produces at least 12 combustion products of unknown toxicity.[4] No clinical study exists — what is known comes entirely from analytical chemistry and community self-reports.
History[edit]
History
Discovery
βk-2C-B first appeared in public discussion in December 2007, when a user on Bluelight.org opened a thread on the compound.[2] Activity was minimal for years. The first formal scientific characterization came in 2015, when Power et al. purchased a commercial sample and identified it using NMR, GC-MS, LC-HRMS, and X-ray crystallography.[1] An earlier attribution to Glennon and colleagues in 2004 has not been verified.citation needed
Market emergence and forensic detection
By 2013–2014, research chemical vendors were marketing βk-2C-B as a legal replacement for 2C-B. Italian forensic laboratories confirmed it in seized materials during 2013–2015,[5] and the U.R.I.To.N. Consortium confirmed its identity by additional methods.[6] A separate study found at least 12 toxic combustion products when the compound was heated in a simulated pipe.[4]
Scheduling and current status
Germany controlled βk-2C-B in November 2016, the UK's blanket psychoactive substance law covered it from May 2016, and Sweden classified it as a narcotic in April 2019.[7] As of 2026, it remains unscheduled in most countries. No clinical trial has been registered and no pharmacological study has been published.
The name βk-2C-B follows research chemical naming conventions: the βk prefix denotes the beta-keto modification, and 2C-B identifies the parent molecule in Shulgin's 2C-x series. The compound also appears as bk-2C-B and beta-keto 2C-B. Its marketing as a legal substitute for 2C-B shaped early perception, though the experience differs substantially in duration, dosage, and stimulant character.
Chemistry[edit]
Chemistry
Structure
βk-2C-B belongs to two overlapping chemical families: the substituted phenethylamines (specifically the 2C-x series) and the substituted cathinones.[1][8] It is the beta-keto structural analog of 2C-B — the same aromatic ring carrying two methoxy groups and a bromine, but with a carbonyl oxygen added to the side chain that converts the phenethylamine structure into a cathinone.[1] Its molecular formula is C₁₀H₁₂BrNO₃ (274.11 g/mol).
The added carbonyl group reduces the compound's fat-solubility compared to 2C-B.[8] This is likely why βk-2C-B requires roughly 4–10 times the dose of 2C-B to produce effects — it crosses into the brain more slowly. Commercially available material is a mixed hydrochloride/hydrobromide salt,[1] and heating it generates at least 12 breakdown products of uncharacterized toxicity.[4]
Pharmacology[edit]
Pharmacology
Mechanism of action
No receptor binding data have been published for βk-2C-B. The bromine and methoxy groups on its aromatic ring — the same pattern found in 2C-B — are associated with serotonin receptor activation,[9][10] the likely basis for the psychedelic effects. The cathinone backbone predicts blockade of dopamine and norepinephrine reabsorption, producing stimulation.[8][11][12] Neither mechanism has been confirmed in a laboratory study.
Pharmacokinetics
No human pharmacokinetic data exist. The beta-keto group reduces fat-solubility, slowing how fast βk-2C-B enters the brain compared to 2C-B[8] — probably explaining the much higher effective dose. Community reports place total duration at 8–12 hours,[2] roughly double that of 2C-B.[13][14] CYP2D6 involvement in metabolism is possible by analogy to related compounds,[15] but this is unconfirmed.
Neuroscience[edit]
Neuroscience
No neuroimaging or neuropharmacological studies have been conducted with βk-2C-B. The neural mechanisms below are extrapolated from its predicted dual pharmacology.
Where it acts
If βk-2C-B activates serotonin receptors as predicted, the expected neural effect is the classic psychedelic signature: disrupted internal narrative, reduced filtering of sensory information, and increased mental noise. At the same time, the cathinone component is predicted to engage reward and arousal circuits through dopamine and norepinephrine — adding stimulation and euphoria through a separate pathway.
Why it matters
The simultaneous engagement of serotonergic psychedelic and catecholaminergic stimulant circuits is pharmacologically unusual. Psychedelics typically quiet goal-directed thinking — stimulants sharpen it. Community reports of empathogenic warmth suggest emotional processing circuits may also be involved, though the mechanism is unknown.
- Does βk-2C-B produce functional serotonin receptor agonism in vivo, or are its psychedelic effects secondary to catecholaminergic mechanisms[10]?
- What explains the 8–12 hour duration — slower brain equilibration, active metabolites, or sustained transporter effects?
- Community reports describe qualitatively different experiences at moderate versus high doses,[3] suggesting distinct pharmacological mechanisms may engage at different dose levels.
Subjective Effects[edit]
The βk-2C-B experience is built on a sustained stimulant foundation overlaid with psychedelic perceptual shifts and social warmth. Physical stimulation runs through the entire arc — more persistent than in most serotonergic psychedelics. Set, setting, and dose exert strong influence; moderate and high doses can feel qualitatively different from each other.[3]
Community reports position it between 2C-B and entactogen-type cathinones, with a perceptual character closer to mescaline-containing cacti than to psilocybin.[2] The stimulant undertone is absent in those comparisons. It is not a lighter version of 2C-B — it is a longer, heavier, more stimulating compound in a distinct experiential category.
Effect Grid
At 80–100 mg, the full psychedelic-stimulant hybrid character emerges. Visual geometry becomes clear — open- and closed-eye patterns, color enhancement, and visual drifting are prominent. Cognitive euphoria and thought acceleration are pronounced, alongside empathogenic effects including emotional enhancement, sociability enhancement, and social connection.
Stimulation is the dominant physical feature, accompanied by pupil dilation, wakefulness, and appetite suppression. Nausea is common during the come-up phase and may last 30–60 minutes. Bruxism, muscle tension, and excessive sweating may occur. Cardiovascular stimulation is expected.
Time alteration is noticeable. Duration is typically 8–10 hours, with insomnia persisting well beyond the subjective offset. Full functional recovery requires at least 12 hours.
Modeled from the effect's dose-dependence curve — not per-substance measurements.
Geometry · Perspective distortion · Symmetrical texture repetition · Depth perception distortion · Tracers · Visual breathing · Environmental patterning · Light sensitivity · Sound sensitivity · Touch enhancement · Visual diffraction · After-images · Visual morphing · Visual haze / noise · Auditory distortion · Auditory enhancement · Peripheral vision distortion · Spatial disorientation · Visual melting · Auditory misinterpretation · Synesthesia · Proprioceptive distortion · Visual acuity enhancement · Object transformations · Object activation · Internal hallucinations · Environmental orbism / cubism · External hallucinations
Tracers · Visual breathing · Environmental patterning · Light sensitivity · Sound sensitivity · Touch enhancement · Visual diffraction · After-images · Visual morphing · Visual haze / noise · Auditory distortion · Auditory enhancement · Peripheral vision distortion · Spatial disorientation · Visual melting · Auditory misinterpretation · Synesthesia · Proprioceptive distortion · Visual acuity enhancement · Object transformations · Object activation · Internal hallucinations · Environmental orbism / cubism · External hallucinations
Appetite suppression · Dry mouth · Heart rate perception changes · Body high · Spontaneous body sensations · Excessive sweating · Restlessness · Insomnia · Dehydration sensation · Tactile euphoria · Tingling / electric sensations · Nausea · Muscle tension · Bruxism · Laughter fits · Vibrations / buzzing · Bodily lightness · Sexual arousal enhancement · Dizziness
Spontaneous body sensations · Excessive sweating · Restlessness · Insomnia · Dehydration sensation · Tactile euphoria · Tingling / electric sensations · Nausea · Muscle tension · Bruxism · Laughter fits · Vibrations / buzzing · Bodily lightness · Sexual arousal enhancement · Dizziness
Conceptual thinking · Cognitive euphoria · Pattern recognition enhancement · Introspection enhancement · Openness enhancement · Cognitive flexibility · Thought acceleration · Thought connectivity · Creativity enhancement · Memory suppression · Thought loops · Humor enhancement · Multiple thought streams · Cognitive impairment · Increased nature relatedness · Analysis enhancement · Focus enhancement · Information processing enhancement · Motivation enhancement · Thought disorganization · Confusion · Delusions
Introspection enhancement · Openness enhancement · Cognitive flexibility · Thought acceleration · Thought connectivity · Creativity enhancement · Memory suppression · Thought loops · Humor enhancement · Multiple thought streams · Cognitive impairment · Increased nature relatedness · Analysis enhancement · Focus enhancement · Information processing enhancement · Motivation enhancement · Thought disorganization · Confusion
Anxiety · Simultaneous emotions · Anxiety suppression · Catharsis · Dysphoria
Dysphoria
Sociability enhancement · Communication enhancement · Derealization · Depersonalization · Boundary dissolution · Ego dissolution
Boundary dissolution · Ego dissolution
Timeline
Initial stimulation and body sensations emerge; nausea may begin. Minimal psychedelic effects — awareness of altered state without prominent perceptual changes. Onset is notably variable across individuals.
Escalating visual and empathogenic effects; body load peaks with nausea and cardiovascular stimulation. Stimulation intensifies alongside emerging color enhancement and visual drifting.
Full psychedelic-stimulant experience — visual geometry, color enhancement, cognitive euphoria, empathogenic warmth, and time alteration at maximum intensity. Pronounced stimulation and wakefulness.
Gradual reduction in visual and psychedelic effects. Stimulation persists longer than perceptual effects. Mood may shift toward fatigue or mild dysphoria.
Residual stimulation, mild mood elevation or fatigue depending on dose. Sleep remains difficult for several hours. Appetite gradually returns.
Safety[edit]
- Acute toxicity
- Moderate
- Chronic toxicity
- Low
- Withdrawal
- None
- Tolerance buildup
- rapid
- Tolerance reset
- 7 days
- Physical
- None
- Psychological
- Negligible
- Compulsive redosing
- Low
- Dose escalation
- Negligible
- Cross-tol.
- LSD · psilo · mesc
Toxicity
Acute toxicity
No controlled toxicological data exist — the toxic and lethal doses are unknown. One unverified community report describes sudden cardiac arrest following use,[3]safety citation needed and a second describes hospitalization after combining βk-2C-B with amphetamine and MDMA during sleep deprivation — too many variables to attribute the outcome clearly.[3] Of 25 community reports on Erowid, 8 are classified as difficult experiences and 3 as disasters.[3]
Cardiovascular risk
The cathinone scaffold raises heart rate and blood pressure. In severe cases, cathinones produce dangerous overheating, muscle breakdown, and organ damage.[12]
βk-2C-B combines cathinone-type cardiovascular stimulation with serotonergic psychedelic activity — a theoretical additive burden that has not been measured.[13][14]
Pyrolysis hazards
Heating βk-2C-B produces at least 12 pyrolysis products, none of which have been toxicologically characterized.[4] Inhaling vaporized or smoked βk-2C-B exposes the user to combustion products of unknown toxicity. Oral administration is the only route with any documented experience base.
Combining βk-2C-B with other drugs substantially increases the risk of serious adverse effects.[16]
Psychological risks
Phenethylamine psychedelics can trigger panic, severe anxiety, and transient psychosis, particularly at higher doses.[8][17] Persistent visual disturbances after the experience — patterns and after-images that remain for weeks or months — are documented across the psychedelic class.[8]
The cathinone component may add extra risk of paranoia and agitation beyond what serotonergic psychedelics produce alone.[12] Community reports suggest most difficult experiences occur above approximately 130–150 mg.[3]
Tolerance and dependence
βk-2C-B is not considered habit-forming. Tolerance builds rapidly — near-complete after a single dose — through serotonin downregulation, a mechanism documented across serotonergic psychedelics.[18] Cross-tolerance with other psychedelics exists,[18] and community consensus places full reset at around 7 days.[2]
Physical dependence and withdrawal have not been reported. Rapid tolerance development prevents the escalating use patterns that typically drive dependence.[12]
Drug interactions
No published interaction data exist for βk-2C-B. All interactions below are inferred from its dual pharmacological class.
- MAOIs (phenelzine, tranylcypromine, moclobemide, selegiline, linezolid): Combined serotonergic activity can trigger serotonin syndrome — a life-threatening overheating and seizure response.[19][16]
- SSRIs and SNRIs: May reduce the psychedelic effect while adding to serotonin overload risk.[19]
- Other serotonergic psychedelics and MDMA: Additive serotonergic burden. At least one hospitalization involved combined βk-2C-B and MDMA use.[3]
- Stimulants (amphetamines, cocaine, methylphenidate): Additive risk of raised heart rate and blood pressure from combined catecholaminergic effects.[3]
- Cannabis: May intensify psychotic symptoms and panic. No βk-2C-B-specific data exist.
- Lithium: Reported to lower seizure threshold when combined with psychedelics. citation needed
- Tricyclic antidepressants: Potential for combined cardiovascular effects via noradrenergic mechanisms. inferred
Contraindications
No substance-specific contraindication data exist. The following are inferred from βk-2C-B's dual pharmacological class.
Absolute (class-inferred):
- Concurrent MAOI use: Risk of serotonin syndrome.[19]
- Known heart condition (high blood pressure, irregular heartbeat, coronary artery disease, heart failure): Combined cardiovascular stimulation from both cathinone and serotonergic activity represents significant unquantified risk. One unverified report describes cardiac arrest.[3] safety citation needed
- Personal or family history of psychotic disorders: Phenethylamine psychedelics can precipitate acute psychosis.[8]
Relative (class-inferred):
- Seizure disorders: Both cathinones and serotonergic psychedelics are associated with lowered seizure threshold.[12]
- Liver impairment: If CYP2D6 mediates metabolism (by analogy to 2C-B-FLY[15]), altered liver function could affect clearance. This is speculative.
- Pregnancy and breastfeeding: No reproductive toxicity data exist. Contraindicated by precautionary principle.
- Concurrent serotonergic medication (SSRIs, SNRIs, triptans, tramadol): Risk of serotonin syndrome and unpredictable interactions.[19]
- CYP2D6 poor metabolizer status: Could prolong or intensify effects if CYP2D6 mediates metabolism. Speculative. inferred
Harm Reduction[edit]
Forms & Identification
βk-2C-B is sold as an unregulated powder with no quality controls. The effective dose range (80–150 mg) demands a milligram-precision scale — a standard kitchen scale is not accurate enough. Reagent testing confirms the presence of a phenethylamine-type compound but cannot distinguish βk-2C-B from structurally similar substances.
Guidelines
- Test every batch with reagent kits before use. A milligram-precision scale is mandatory at this dose range.
- Start at the low end of the reported range and wait at least 2–3 hours before considering redosing — onset can be slow and unpredictable.
- Clear the entire day. The 8–12 hour duration plus residual stimulation extends well beyond the primary effects.
- Eat a light meal 2–3 hours before. Hydrate steadily but do not overhydrate.
- Have a sober sitter present, particularly above 130 mg.
- Do not smoke or vaporize this compound. Heating produces toxic pyrolysis products.[4]
- Do not redose to chase effects — the slow onset and long duration make compounding doses a significant risk.
Set & Setting
The 8–12 hour duration makes environment planning essential — a comfortable, familiar space with no obligations for the full day is the minimum. The stimulant component means sleep will not be possible for many hours after ingestion. A trusted, sober companion is strongly recommended, especially at doses approaching or exceeding 130 mg.
Aftercare & integration. The extended duration and stimulant component often leave users physically drained. Prioritize sleep, hydration, and nutrition in the 24–48 hours following use. Residual stimulation may make falling asleep difficult — avoid caffeine and allow the body to wind down naturally.
If the experience was psychologically intense or distressing, journaling and conversation with a trusted person can help process what emerged. Professional psychedelic integration support is appropriate if distressing material persists beyond a few days.
Recovery & Support
βk-2C-B is not considered physically addictive, and compulsive use patterns are rare due to rapid tolerance. If use has become a coping mechanism or is causing disruption in daily life, this reflects a pattern worth examining regardless of the substance's pharmacological dependence profile. Peer support communities, harm reduction organizations, and therapists experienced with substance use can provide confidential, non-judgmental support.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency: chest pain, racing or irregular heartbeat, seizure, loss of consciousness, body temperature hot to the touch, severe confusion, or self-harm behavior all require immediate help. Intense anxiety or a difficult psychological experience is not the same as a medical emergency — reassurance, a calm environment, and patient companionship are usually sufficient.
Immediate steps:
- 1. Move the person to a safe, quiet space.
- 2. Call emergency services if chest pain, seizure, loss of consciousness, or dangerously high body temperature are present.
- 3. Do not restrain the person unless they are in immediate physical danger.
- 4. If the person is unconscious but breathing, place them in the recovery position.
- 5. Do not induce vomiting.
What to tell the dispatcher: Name the substance (βk-2C-B / beta-keto 2C-B), approximate dose, time of ingestion, and current symptoms. Be honest about what was taken. Good Samaritan laws in many jurisdictions protect people who call for help during a drug-related emergency.
Legal Status[edit]
Legal Status
βk-2C-B is not internationally scheduled under United Nations conventions. Control varies by jurisdiction — some countries have scheduled it specifically, others rely on blanket psychoactive substance laws, and others have not addressed it at all.
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United States | Unscheduled (federal) | Not explicitly listed in DEA Schedules. The Federal Analogue Act may apply if βk-2C-B is deemed substantially similar to 2C-B (Schedule I), making production, sale, or possession with intent for human consumption a potential federal offense. Interpretation is case-dependent.[7] |
| United Kingdom | Controlled (Psychoactive Substances Act 2016) | Illegal to produce, supply, or import under blanket psychoactive substance legislation, effective May 26, 2016. Personal possession is not an offense under this Act.[7] |
| Germany | Controlled (NpSG) | Covered under the Neue-psychoaktive-Stoffe-Gesetz (New Psychoactive Substances Act), effective November 26, 2016.[7] |
| Switzerland | Controlled (named substance) | Listed as a named substance under Verzeichnis E of Swiss narcotics legislation.[7] |
| Sweden | Narcotic | Classified as a narcotic substance as of April 5, 2019.[7] |
| Canada | Reported Schedule III (CDSA) | Reported as Schedule III under the Controlled Drugs and Substances Act as of October 2016. Canada Gazette Order SOR/2016-73 added 2C-phenethylamine derivatives to Schedule III;[20] however, βk-2C-B is not explicitly named in that Order. Its coverage may depend on class language or a separate order. citation needed |
| Australia | Unconfirmed | Not specifically scheduled under federal or state legislation at the time of research. The cathinone and phenethylamine analogue provisions may apply. citation needed |
Analog and structural considerations
βk-2C-B's hybrid structure complicates its classification. In jurisdictions with structural analog provisions — such as the US Federal Analogue Act — it could be prosecuted as an analog of 2C-B based on the shared aromatic scaffold, or as an analog of scheduled cathinones based on the beta-keto backbone. Neither interpretation has been tested in court for this compound.
references
- [1]
- [2]
- [3]
- [4] ^abcdeTexter KB, Waymach R, Kavanagh PV, O'Brien JE, Talbot B, Brandt SD, Gardner EA (2018) Identification of pyrolysis products of the new psychoactive substance 2-amino-1-(4-bromo-2,5-dimethoxyphenyl)ethanone hydrochloride (bk-2C-B) and its iodo analogue bk-2C-I — Drug Testing and Analysis doi:10.1002/dta.2200
- [5] ^Odoardi S, Romolo FS, Strano-Rossi S (2016) A snapshot on NPS in Italy: Distribution of drugs in seized materials analysed in an Italian forensic laboratory in the period 2013-2015 — Forensic science international doi:10.1016/j.forsciint.2016.01.037
- [6] ^Bertol E, Vaiano F, Mari F, Di Milia MG, Bua S, Supuran CT, Carta F (2017) Advances in new psychoactive substances identification: the U.R.I.To.N. Consortium — Journal of Enzyme Inhibition and Medicinal Chemistry doi:10.1080/14756366.2017.1333987