2C-B vs. Tusi (Pink Cocaine): They Are Not the Same Drug

Tusi and 2C-B are not the same drug. The name “tusi” (also spelled “tucibi,” “tuci,” or “toosie”) is a Spanish phonetic rendering of “2C-B” — but what’s actually sold under that name in the US and Europe is almost always a different mixture entirely, most commonly MDMA and ketamine with a pink dye. Lab testing data consistently finds little to no 2C-B in samples sold as tusi. This confusion is genuinely dangerous because the harm profiles, interaction risks, and overdose presentations are completely different.

Quick answers

Is tusi the same as 2C-B? No. The name comes from 2C-B but the drug sold as tusi typically contains MDMA and ketamine, not 2C-B. Lab analysis of dozens of US samples found 2C-B absent in the vast majority.

What is pink cocaine actually made of? Drug checking data shows most tusi samples contain ketamine (~90–95% of samples) and MDMA (~60–80%), with variable amounts of caffeine, cocaine, synthetic cathinones, and occasionally methamphetamine. The pink color comes from food dye, not any active ingredient.

Is tusi dangerous? Yes — partly because its composition is completely unpredictable. Every batch is different. The MDMA+ketamine combination carries specific risks including hyperthermia, severe dissociation, and cardiovascular stress that 2C-B alone does not.

Is there any way to know what’s in a tusi sample? Only by testing it. Standard reagent kits (Marquis, Mecke, Simon’s) can distinguish MDMA, ketamine, and 2C-B. A fentanyl test strip should always be used as well — fentanyl has been detected in some tusi samples.

What should I do if someone has a bad reaction to tusi? Call emergency services. Tusi reactions can involve dissociation, overheating, cardiovascular distress, or seizures — combinations that can escalate quickly and may not respond to typical harm reduction interventions alone.

Where the name “tusi” comes from

2C-B (4-bromo-2,5-dimethoxyphenethylamine) is a synthetic psychedelic phenethylamine developed by Alexander Shulgin in the 1970s. In Latin America — particularly Colombia — it became known on the street as “tusi,” a phonetic shorthand for how “2CB” sounds when said in Spanish. In its early Colombian incarnation, tusi was genuinely expensive and sometimes actually contained 2C-B, often mixed with pink food coloring as a branding marker.

As demand spread and real 2C-B became harder to source in quantity, traffickers substituted cheaper, more available ingredients. By the time “pink cocaine” or tusi arrived in the US and European club scenes in significant quantities (roughly 2017–2020), the original drug had been almost entirely replaced by a ketamine-and-MDMA blend. The name stuck, but the contents did not.

What lab testing actually finds in tusi

The published forensic record is unambiguous. A 2023 analysis by Palamar et al. in the American Journal of Drug and Alcohol Abuse (PMID 37162319) reviewed DrugsData.org submissions of samples sold as tusi, pink cocaine, or 2C-B: of 68 samples tested between 2016 and 2024, 94% contained ketamine and 81% contained MDMA. Actual 2C-B compounds were rarely detected.

A 2025 case series from the Miami-Dade County Medical Examiner by Moore et al. in the Journal of Forensic Sciences (PMID 40082214) analyzed eight fatal cases involving colored powders sold as tusi between 2020 and 2024. None of the powders contained 2C-B. All decedents had multiple drugs in postmortem blood, with ketamine and MDMA present across cases alongside cocaine and other substances.

Spanish drug checking data reinforces the same picture: within 470 samples analyzed in Spain, 36 distinct substances were detected — with ketamine (93.2%) and MDMA (92.1%) appearing in nearly every sample, and 2C-B rarely or never found.

The practical implication: if you have obtained something sold as tusi, pink cocaine, 2C-B, or tucibi, you almost certainly do not have 2C-B. You likely have MDMA and ketamine plus unknown adulterants. The only way to know what is in your sample is to test it.

What actual 2C-B is — and is not

2C-B is a serotonergic psychedelic with a well-characterized pharmacological profile. It acts primarily as a partial agonist at 5-HT2A and 5-HT2C receptors and as an α1-adrenergic agonist. It produces dose-dependent psychedelic and entactogenic effects lasting 4–6 hours at recreational doses (typically 10–25 mg orally).

The first controlled human pharmacology study of 2C-B — Papaseit et al. 2018, published in Frontiers in Pharmacology (PMID 29593537) — documented moderate cardiovascular stimulation (elevated heart rate and blood pressure), subjective euphoria, and altered perception in 16 healthy experienced users at doses of 10–20 mg. A 2023 controlled study by Mallaroni et al. in Clinical Pharmacology & Therapeutics (DOI: 10.1002/cpt.2958) compared 2C-B directly to psilocybin, confirming 2C-B’s distinct pharmacological profile with stronger entactogenic and milder classical-psychedelic characteristics.

Critically: 2C-B has no stimulant activity, no dopamine-releasing mechanism, and does not produce the dissociative effects characteristic of ketamine. Its mechanism and risk profile are nothing like the MDMA+ketamine combination that tusi actually is. The harm reduction strategies, overdose signs, and interaction contraindications for 2C-B are not interchangeable with those for tusi.

For a detailed breakdown of 2C-B’s effects, dosing, and harm reduction, see our 2C-B harm reduction guide.

Why the MDMA + ketamine combination carries specific risks

Tusi’s actual composition — primarily MDMA and ketamine — creates a distinct risk profile that comes from combining two drugs with very different mechanisms.

MDMA is a monoamine releasing agent that floods the synapse with serotonin, dopamine, and norepinephrine. It raises body temperature, impairs thermoregulation, and causes water retention (relevant to hyponatremia risk). For a full profile see our MDMA harm reduction guide.

Ketamine is a dissociative NMDA receptor antagonist. It impairs coordination, judgment, and the ability to recognize overheating or distress. At the doses ketamine appears in tusi samples — potentially up to 90% of the powder by mass — dissociation can be severe. For a full profile see our ketamine harm reduction guide.

The combination specifically:

Hyperthermia risk is amplified. MDMA impairs the body’s ability to regulate heat. Ketamine impairs your ability to notice you are overheating — you cannot feel discomfort clearly, you will not seek cooling, and your dance behavior will not slow appropriately. This is a dangerous combination at a festival or club.
CNS depression + stimulation mix. The combination creates unpredictable CNS effects — ketamine’s dissociative sedation paired with MDMA’s stimulant cardiovascular load produces erratic heart rate and blood pressure patterns.
Judgment and consent. Ketamine at significant doses produces profound dissociation and memory impairment. Combined with MDMA’s disinhibiting effects, this combination is associated with reduced capacity to make or communicate decisions.
Preclinical signals on neurotoxicity. One animal study (PMID 18666708) found that binge ketamine pretreatment aggravated MDMA-induced dopaminergic toxicity in mice. Important caveat: the doses used were many times higher than recreational human doses (50 mg/kg ketamine × 7 doses and 20 mg/kg MDMA × 3 doses in mice). This result cannot be directly applied to human recreational use, but it does provide a mechanistic basis for concern about combined use at high or repeated doses.
Unknown adulterants. Because tusi batches vary so widely, you may also be ingesting synthetic cathinones, methamphetamine, cocaine, opioids, or benzodiazepines without knowing it. Each of these adds its own interaction risk on top of the ketamine+MDMA baseline.

Use our interaction checker to review specific combinations before using any substance.

Testing is the only way to know what you have

No test kit can confirm every substance in a complex mixture, but reagent testing can tell you a great deal:

Marquis reagent will react purple/black with MDMA. It gives no reaction (or very faint yellow) with 2C-B and no reaction with ketamine. If you get a strong purple-black, MDMA is present.
Mecke reagent turns blue-green with MDMA and blue-black with 2C-B — useful for distinguishing them.
Simon’s reagent is positive (blue) for secondary amines like MDMA; 2C-B is a primary amine and will not react.
Fentanyl test strips should be used on every tusi sample. Fentanyl has been detected in tusi and pink cocaine sold in the US.

The DanceSafe Complete Testing Kit includes all major reagents and instructions for exactly this kind of multi-substance testing: dancesafe.org — Complete Set of All 9 Testing Kits. You can also watch real-time testing demos in our test kit video guides.

A clean reagent test is not a guarantee of safety — it can only detect the substances those reagents react with. But a test that confirms MDMA and fails to find any 2C-B reaction is a strong signal that what you have is not what it was sold as.

The harm reduction bottom line

The name “pink cocaine” or “tusi” tells you almost nothing reliable about what a sample contains. The drug originally behind the name — 2C-B — is absent from the overwhelming majority of samples tested in forensic and drug checking analyses. What you are almost certainly getting is a ketamine-dominant powder plus MDMA, with an unpredictable mix of additional substances that varies by batch and source.

The combination’s risks are real and specific: hyperthermia, severe dissociation, cardiovascular load, impaired judgment, and unknown adulterant exposure. These are not the same risks as 2C-B, and harm reduction strategies designed for 2C-B do not substitute for understanding what tusi actually contains.

Test every sample before use. Know the signs of hyperthermia. Never use alone. See our 2C-B guide, MDMA guide, and ketamine guide for full harm reduction detail on each of the substances likely to be in a tusi sample.