2C-B

What 2C-B Is

2C-B is a synthetic psychedelic phenethylamine, chemically 4-bromo-2,5-dimethoxyphenethylamine. It belongs to the 2C-x family, compounds built on 2,5-dimethoxyphenethylamine with different substitutions at the 4-position. The bromine at that position is what makes this one 2C-B rather than 2C-I, 2C-E, or 2C-P, and those relatives differ from it in potency, duration, and risk more than the shared family name suggests.

What a reader encounters is usually a white or off-white crystalline powder, sold loose, in capsules, or as a pressed pill. The active dose is small enough that a capsule looks close to empty, which matters more here than for most substances because 2C-B has an unusually steep dose-response curve.

One thing worth settling early: a pink powder sold as tusi, tucibí, or pink cocaine is usually not 2C-B and often contains none of it. That is a sourcing problem rather than a naming quibble, and it is covered in where it comes from.

Where 2C-B Comes From

2C-B is entirely synthetic and has no natural source. It is made in a laboratory from commercially available precursors, and there is no organism anywhere that produces it. That makes the sourcing question a purely human one: not what grew it, but who made it, and whether what they made is what you were told.

The answer is frequently no, and the reason is structural. 2C-B is one member of a large family of closely related compounds that look identical as powders, cost the manufacturer roughly the same, and behave very differently in a person. Substitution within that family is the central risk of buying 2C-B, and it is a more serious risk than contamination.

The substitutions that matter

The NBOMe series is the dangerous one. 25B-NBOMe is 2C-B with a benzyl group added to the nitrogen, and that single modification makes it active in the range of hundreds of micrograms rather than tens of milligrams. Someone weighing out 20 mg of what they believe is 2C-B and receiving 25B-NBOMe has taken something on the order of twenty to fifty times an active dose. NBOMes have caused numerous deaths, and unlike 2C-B they carry real vasoconstrictive and seizure risk. They are also bitter and numbing on the tongue, whereas 2C-B is not, which is the one crude field check available.

Other 2C-x compounds are substituted more casually. 2C-E is considerably more psychologically demanding at comparable doses, 2C-P is much more potent and much longer, and 2C-T-7 has a history of fatalities, particularly when insufflated. None of these is a rounding error against 2C-B.

Tusi, which is mostly not 2C-B

Since the 2010s a pink powder has circulated widely in Latin America, Spain, and increasingly North America under the names tusi, tucibí, or pink cocaine. The name is a phonetic rendering of "2C," and that is roughly where the connection ends. Demand outran supply, and the label attached itself to a dyed mixture that varies enormously between batches. Drug-checking data has repeatedly found ketamine as the dominant ingredient, frequently alongside MDMA, caffeine, methamphetamine, cocaine, or novel compounds. One drug-checking service in Chile reported that of samples submitted as 2C, the overwhelming majority contained ketamine and well under one percent contained anything from the 2C family at all.

Two practical points follow. Pink powder tells you a dye was added and nothing else. And a person who takes tusi expecting a 2C-B experience is most often taking a dissociative and a stimulant together, with the risk profile of ketamine rather than of a phenethylamine psychedelic.

History & Cultural Roots

2C-B has no traditional lineage, no ceremonial context, and no Indigenous history. It has an inventor, and his notes. Alexander Shulgin first synthesised it in 1974 as part of a systematic exploration of substituted phenethylamines, and he rated it highly enough that it became one of the small number of his compounds to reach any real circulation. He published the synthesis and his self-experimentation notes in PiHKAL: A Chemical Love Story in 1991, co-written with Ann Shulgin.

The decade in between is the strangest part of the story. Before it was controlled anywhere, 2C-B was sold openly and legally in the United States and parts of Europe, marketed as an aphrodisiac under trade names including Erox and Nexus, and stocked in smart shops and adult stores. When MDMA was placed in Schedule I in 1985, 2C-B filled some of the gap it left. That commercial window closed in 1995, when the DEA scheduled it.

What it acquired instead was a club and festival association, and later the tusi phenomenon described above, in which the name outlived any reliable connection to the compound. For a substance barely fifty years old, 2C-B has already had its identity taken over by something else twice.

Pharmacology

Like classical psychedelics, 2C-B acts as a 5-HT2A receptor agonist. It also has significant activity at other serotonin receptor subtypes and some dopaminergic activity, producing a phenomenological character that many describe as combining qualities of psilocybin's warmth with MDMA's entactogenic sensibility, more visually elaborated than MDMA, more embodied and sensory than LSD.

The phenethylamine structure means 2C-B is metabolised differently from tryptamine psychedelics. It is not a substrate for MAO in the same way as DMT, meaning MAOIs do not dramatically potentiate it in the way they do ayahuasca. However, serotonergic interactions and combination risks still apply.

Effects

Onset (45–75 minutes)

Relatively slow onset, which has led to redosing accidents when users assume the first dose is not working. The onset is gradual and typically pleasant: a gentle warmth and perceptual brightening, mild tingling.

Peak (2–4 hours)

2C-B is characterised by strong visual effects even at moderate doses, colour enhancement, patterns, and figurative imagery are prominent. The emotional quality is often described as warm, sensory, and grounded rather than the emotionally confrontational intensity of psilocybin at equivalent experiential depth. Music, touch, and embodied sensation are typically heightened. The experience is often described as more navigable and less psychologically destabilising than psilocybin or LSD at comparable doses.

Duration

4–6 hours total, comparable to psilocybin, notably shorter than LSD. This is one of 2C-B's practical advantages: the experience is briefer and the return to baseline is typically clean, without LSD's long tail.

Dosage: The Most Critical Consideration

2C-B has one of the steepest dose-response curves of any psychedelic. The difference between 15 mg, 25 mg, and 35 mg is qualitatively distinct territory rather than a gradual progression. This is the most important harm reduction consideration for 2C-B.

2C-B vs. Psilocybin and LSD

Duration. 2C-B (4–6 hours) is comparable to psilocybin and substantially shorter than LSD, a practical advantage for many users.

Visual character. 2C-B's visuals are typically more elaborated and more stable than psilocybin at equivalent doses, geometric, colourful, and detailed. LSD visuals tend to be crisper and more motion-based.

Emotional character. 2C-B is generally less emotionally confrontational than psilocybin. It tends not to produce the profound ego dissolution or the deeply psychological material that psilocybin frequently surfaces, which practitioners describe both as a limitation (for deep therapeutic work) and as an advantage (for people new to psychedelics or seeking a more navigable experience).

Ecological phenomenology. 2C-B produces ecological and relational themes less consistently than psilocybin or ayahuasca in the available literature. Its more sensory and visual character may support embodied presence without the profound relational insights characteristic of tryptamine psychedelics.

Tolerance. Rapid tolerance develops within days; cross-tolerance with psilocybin and LSD is substantial.

What the Research Shows

Very little, and saying so plainly is more useful than assembling the fragments into something that looks like a body of evidence. There are no modern controlled clinical trials of 2C-B in humans. There is no efficacy data for any condition, no established safety profile from supervised administration, and no long-term follow-up of anyone.

What exists falls into four categories. Shulgin's own detailed self-experimentation notes, which are careful and honest but are one chemist's subjective reports rather than controlled research. Receptor pharmacology and animal work establishing 5-HT2A agonism and the broad shape of its activity. Analytical and forensic chemistry, much of it generated by drug-checking services and poison centres. And survey data from large drug-use questionnaires, which tells you what people report doing and experiencing but cannot separate 2C-B from everything taken alongside it.

The forensic and case-report literature is worth treating carefully for a specific reason: it is generated almost entirely by things going wrong. Emergency presentations get written up and uneventful evenings do not, so the published record skews hard toward harm and cannot be read as a base rate. It is equally not evidence of safety.

What the gap actually means for you

Three things. The dose ranges given on this page and everywhere else come from user reports rather than from measured dose-response studies, which is part of why the margins between them are treated so cautiously here. Interaction risks are inferred from what is known about serotonergic psychedelics as a class rather than tested for 2C-B specifically, so the medication cautions below are extrapolation and should be treated conservatively rather than dismissed as unproven. And nothing is known about long-term or heavy use, which is a genuine unknown rather than a reassuring silence.

This is one of the few substances covered here where the research library holds nothing, and that absence is deliberate. A citation that does not support what it is being used to claim would be worse than an empty shelf.

Risks and Contraindications

2C-B shares standard psychological contraindications with all classical psychedelics: personal or family history of schizophrenia spectrum disorders or bipolar I. Cardiovascular: moderate increase in heart rate and blood pressure. The same drug interaction considerations apply, particularly with SSRIs, MAOIs, and lithium.

Redosing risk. 2C-B's slow onset frequently prompts impatient redosing before the first dose has taken effect. A dose taken at 45 minutes that seems to have done nothing will often arrive in full force at 60–90 minutes, combined with the redose, this can produce an unexpectedly intense experience. Wait a minimum of 90 minutes before concluding that a dose has not worked.

Adulteration. 2C-B is sometimes sold as MDMA or mixed with other substances. Testing is essential.

Testing 2C-B

The Marquis reagent turns yellow-green for 2C-B (distinct from MDMA's purple/black). The Mecke reagent turns blue-green. The Froehde reagent turns orange-brown. Using multiple reagents provides better confidence than any single test. Fentanyl test strips should always be used as an additional check.

The limit worth understanding is that reagents identify a family rather than a member of it. A colour consistent with 2C-B is also broadly consistent with other 2C-x compounds, and reagent kits are not reliable for separating NBOMe compounds from the 2C-x compounds they are derived from. Given the dose difference described in where it comes from, that is the gap that matters most.

Two habits partly close it. NBOMe compounds are strongly bitter and numb the tongue, and 2C-B is not, so an unexpected bitter numbness is a reason to stop rather than a curiosity. And laboratory analysis through a service such as DrugsData or an in-person drug-checking site is the only method that names the specific compound. For something with this dose profile, that is worth the wait.

Legal Status

2C-B is controlled almost everywhere, and in several places more severely than psilocybin. It was added to Schedule II of the 1971 UN Convention on Psychotropic Substances in 2001, so unlike ketamine it sits on an international treaty floor that national law has to meet.

United States: Schedule I since 1995. The wider family was dealt with separately and later: a group of other 2C-x compounds was explicitly scheduled by federal legislation in 2012, and the NBOMe compounds were brought under control from 2013. Where a specific analogue is not named, the Federal Analogue Act can still apply if it is intended for human consumption.

Canada: Schedule III under the Controlled Drugs and Substances Act.

United Kingdom: Class A, Schedule 1 under the Misuse of Drugs Act, the most serious tier. This surprises people who assume a lesser-known compound carries lesser penalties. It sits alongside heroin and cocaine for sentencing purposes, and the other 2C compounds are treated the same way.

Elsewhere: controlled in most of Europe, Australia, and Latin America, though enforcement against tusi specifically is complicated by the fact that the powder often contains something other than the substance its name refers to. See the legal quick reference for comparison across substances.

If You Are Considering This

The general preparation applies and lives on assessment, preparation, and integration. Three things are specific to 2C-B, and all three come back to milligrams.

You need a scale, and it needs to be the right kind

This is the substance on the site where eyeballing is least survivable. The gap between a moderate and a difficult dose is single-digit milligrams, and no jeweller's scale sold for kitchen use resolves that reliably at the bottom of its range. A milligram-accurate scale, calibrated, weighing an amount well above its minimum, is the baseline. If you are working from a capsule someone else filled, you do not know the dose and the dosage table cannot help you.

The slow onset is the trap

Forty-five to seventy-five minutes is long enough for a person to conclude with real confidence that nothing is happening. Redosing at that point is the most common way a manageable 2C-B evening becomes an overwhelming one, because both doses then arrive together on an already steep curve. Decide the wait before you take anything, make it ninety minutes minimum, and treat the decision as already made rather than as something to revisit while impatient.

Take the unknowns seriously in both directions

Because there is almost no research, there is no reassurance available about heavy or repeated use, and no measured guidance on medication interactions beyond what applies to serotonergic psychedelics generally. Treat the SSRI, MAOI, and lithium cautions as firm rather than provisional. Verify what you have before the day rather than on it, since lab testing takes time and is the only thing that separates 2C-B from its more dangerous relatives.

2C-B is frequently described as one of the more manageable psychedelics, and at a known dose of a verified compound that description is fair. Both of those qualifiers are doing real work.

Frequently Asked Questions