Every substance, clearly explained

1P-LSD is a chemical relative of LSD that acts as a prodrug — the body converts it into LSD — so its effects are essentially indistinguishable from LSD. It is not scheduled by name in the US but is prosecutable as an LSD analogue under the Federal Analogue Act, and is explicitly banned in many other countries.

2-FDCK (2-fluorodeschloroketamine) is a synthetic dissociative and a close chemical analogue of ketamine sold as a research chemical. It is presumed to work like ketamine as an NMDA-receptor antagonist, but its pharmacology and safety in humans are largely unstudied — a key point of caution.

25I-NBOMe (also called N-bomb or Smiles) is an extremely potent synthetic hallucinogen active at microgram doses. It is frequently sold as LSD on blotter paper, and because it is far more toxic than LSD, people who take it believing it is acid have died. Describing this danger is its whole reason for being catalogued.

Detailed, medically-reviewed information for 2C-B is being prepared.

2C-E is a psychedelic phenethylamine from the 2C family first made by chemist Alexander Shulgin. Like its relative 2C-B, it works mainly by activating serotonin 5-HT2A receptors. It is one of the more potent and longer-lasting 2C compounds, with a notable body load and real overdose risk.

2C-I is a psychedelic phenethylamine from Alexander Shulgin's 2C family, closely related to 2C-B and 2C-E. It produces its effects by activating serotonin 5-HT2A receptors. It is milder and shorter than 2C-E, but should not be confused with the far more dangerous NBOMe compound sold as "Smiles."

2C-T-7 ('Blue Mystic') is a synthetic psychedelic phenethylamine from Alexander Shulgin's 2C-x family, known for a heavy, unpredictable body load and a dangerous dose-sensitivity. It is a Schedule I controlled substance in the US, and is directly linked to multiple deaths — especially when snorted at higher amounts or combined with stimulants like MDMA.

3-MMC (metaphedrone) is a synthetic cathinone stimulant closely related to mephedrone, which it largely replaced after mephedrone was banned. It acts on dopamine, norepinephrine, and serotonin, produces short-acting stimulant and mild empathogenic effects, and carries a high risk of compulsive redosing and dependence.

4-AcO-DMT (psilacetin, "synthetic mushrooms") is a synthetic tryptamine that the body converts into psilocin — the same active compound produced by psilocybin mushrooms. Its effects are reported to be very similar to psilocybin. Its risks broadly mirror those of psilocybin, with the added uncertainties of an unregulated research chemical.

4-HO-MET (metocin) is a synthetic psychedelic tryptamine and close structural analogue of psilocin, the active compound in magic mushrooms, producing broadly similar effects. It is not federally scheduled by name in the US but can be prosecuted as a psilocin analogue under the Federal Analogue Act, and some states have scheduled it explicitly.

5-MeO-DMT is an extremely potent, fast, short-acting psychedelic tryptamine found in certain plants and in the venom of the Colorado River toad. It differs from DMT and psilocybin in acting strongly at the serotonin 5-HT1A receptor. Its risks include overwhelming experiences, dangerous MAOI interactions, and, in toad-derived material, cardiotoxins.

6-APB (Benzo Fury) is a synthetic stimulant-entactogen of the benzofuran class, structurally related to MDA and producing MDMA-like effects. It is not scheduled by name in the US but is prosecutable as an MDA analogue under the Federal Analogue Act; it has been linked to deaths, and products sold under this name often contain other substances.

Detailed, medically-reviewed information for 7-Hydroxymitragynine (7-OH) is being prepared.

Adderall is a prescription stimulant of mixed amphetamine salts for ADHD and narcolepsy, and a Schedule II controlled substance widely misused for studying, wakefulness, and weight loss. Its risks are cardiovascular (raised heart rate and blood pressure, rare sudden cardiac events), psychiatric (anxiety, paranoia, stimulant psychosis at high doses), and dependence-related — plus fentanyl or methamphetamine contamination in counterfeit pills bought outside a pharmacy.

Alcohol is a legal but widely harmful depressant; risks rise with the amount consumed and include addiction, organ damage, cancer, and overdose.

Amanita muscaria (fly agaric) is the iconic red-and-white-spotted mushroom, psychoactive through muscimol and ibotenic acid — NOT psilocybin. Its effects are sedative and dream-like (acting on GABA-A receptors, closer to alcohol or a sedative than a classic psychedelic). It is federally unscheduled and legal in the US except Louisiana, but it is genuinely toxic and the commercial product market is riddled with contamination and mislabeling.

Amphetamine (e.g., Adderall) is a prescription stimulant for ADHD and narcolepsy; misuse strains the heart, can cause dependence and psychosis, and is dangerous combined with other drugs.

Amyl nitrite is one specific alkyl nitrite in the group commonly sold as 'poppers' (see the poppers page for the full effects and risks). Unlike the others, it has a genuine medical history — it was used to treat angina and as a cyanide-poisoning antidote. Inhaled recreationally it produces a brief head-rush and muscle relaxation, and shares poppers' central danger: methemoglobinemia, which is especially severe if swallowed rather than inhaled.

Ayahuasca is a psychoactive brew, traditionally from the Amazon, that combines a DMT-containing plant with a vine containing MAO-inhibiting harmala alkaloids. The MAOI makes the normally oral-inactive DMT active by mouth. Its most important safety issue is dangerous interactions with serotonergic drugs such as antidepressants.

Barbiturates are a class of central-nervous-system depressant drugs derived from barbituric acid, once widely used as sedatives, sleep aids, and anticonvulsants. Examples include phenobarbital (Luminal), secobarbital (Seconal), pentobarbital, and amobarbital. They have largely been replaced in medicine by benzodiazepines because barbiturates carry a much higher overdose risk: the gap between an effective dose and a fatal one is narrow. Phenobarbital remains in use as an anti-seizure medication.

Benzodiazepines ('benzos') are a class of prescription central-nervous-system depressants used medically for anxiety, insomnia, seizures, and alcohol withdrawal. They calm the brain by enhancing the effect of GABA, the main inhibitory neurotransmitter. Common examples include alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium), and lorazepam (Ativan), each covered on its own page. The defining harm-reduction fact about this class is that physical dependence develops predictably with regular use, and abrupt withdrawal can be life-threatening.

Buprenorphine is an opioid used to treat opioid addiction and pain; its 'partial' action makes overdose less likely on its own, but it is dangerous mixed with other depressants.

CBD (cannabidiol) is a non-intoxicating cannabis compound widely sold in oils, edibles, and topicals, with one FDA-approved prescription form (Epidiolex) for certain epilepsies. Hemp-derived CBD has been federally legal since the 2018 Farm Bill, but a 2025 law redefining hemp by total THC takes effect November 12, 2026 and may sweep in some CBD products.

Caffeine is the world's most widely used stimulant; it is safe for most adults in moderate amounts but can cause dependence, and pure or highly concentrated caffeine powders can be fatal.

Cannabis is a widely used plant drug whose main psychoactive compound is THC; risks include impairment, dependence, and — for some — anxiety or psychosis. Its U.S. legal status is in active flux.

Cathinone is a stimulant compound — the natural active ingredient in the khat plant, and the chemical parent of the synthetic 'bath salts' family (mephedrone, MDPV, methylone, alpha-PVP/'flakka' and others). Structurally related to amphetamine, cathinones range from the mild natural compound to potent, dangerous synthetics linked to psychosis and death. Natural cathinone is Schedule I in the US; most synthetic cathinones are Schedule I or prosecutable as analogues.

Clonazepam (Klonopin) is a benzodiazepine for seizures and panic; it causes dependence, is dangerous with opioids or alcohol, and withdrawal can include seizures.

Cocaine is a powerful, short-acting stimulant that strains the heart and is highly habit-forming; street supply is increasingly contaminated with fentanyl.

Codeine is a milder opioid used for pain and cough; it converts to morphine in the body, carries opioid overdose and dependence risk, and is dangerous mixed with other depressants.

Crack is the freebase, smokable form of cocaine — the same drug pharmacologically, but because it is smoked rather than snorted, it reaches the brain faster and produces a shorter, more intense high that makes it more addictive. It shares cocaine's core risks (see the cocaine page for full detail) plus route-specific harms from smoking, and it carries a distinct US legal history: the crack/powder sentencing disparity.

DMT is a powerful, short-acting psychedelic (the key compound in ayahuasca); risks are mainly psychological, plus dangerous interactions when combined with MAOIs or other serotonergic drugs.

DOM (STP) is a long-lasting synthetic psychedelic amphetamine of the DOx family, active at very low doses and notorious for an extremely long duration that has historically led to accidental overdose and prolonged, distressing trips. It is a Schedule I controlled substance in the US.

DXM (dextromethorphan) is a common over-the-counter cough suppressant that is safe at recommended doses but produces dissociative, PCP-like effects when misused in large amounts; combination cough-and-cold products make overdose especially dangerous.

Delta-8 THC is an intoxicating cannabinoid, milder than regular (delta-9) THC, usually manufactured from hemp-derived CBD and sold widely in gummies and vapes. It has occupied a post-2018-Farm-Bill legal gray area, but a 2025 federal law redefining hemp by total THC takes effect November 12, 2026 and is expected to make most delta-8 products federally illegal.

Diazepam (Valium) is a long-acting benzodiazepine for anxiety, seizures, and muscle spasm; it causes dependence, is dangerous with opioids or alcohol, and withdrawal can be dangerous.

'Ego death' (or ego dissolution) is an experience — usually from high-dose psychedelics — where the normal sense of being a separate 'self' temporarily falls away, sometimes described as merging with everything or ceasing to exist as an individual. It can feel profound and meaningful or terrifying, and how a person handles it depends heavily on preparation, dose, and set and setting.

Ephedrine is a stimulant and decongestant, related to amphetamine, found in the ephedra plant and in some cold medicines. It is not a controlled substance, but pure ephedrine is a DEA List I chemical (a methamphetamine precursor), OTC sales are restricted under the Combat Methamphetamine Epidemic Act, and ephedra weight-loss supplements are FDA-banned over cardiac risks.

Etizolam is a thienodiazepine that acts like a benzodiazepine and is sold largely through the unregulated designer-drug market, sometimes faked as pharmaceutical alprazolam. As of April 1, 2026 it is a permanent Schedule I controlled substance in the US. It carries the full benzodiazepine risk set — dependence, seizure-risk withdrawal, and lethal additive depression with opioids or alcohol — compounded by fentanyl contamination in illicit supply.

Fentanyl is a synthetic opioid far more potent than heroin or morphine, now the leading driver of U.S. overdose deaths — often hidden in other drugs.

GBL is an industrial solvent that the body converts into GHB; it is a depressant with the same dangers as GHB — overdose, dependence, and lethal interaction with alcohol — and acts faster.

GHB (gamma-hydroxybutyrate) is a central nervous system depressant used recreationally as a euphoriant and sedative, and medically (as sodium oxybate) for narcolepsy. Its defining danger is a very steep dose-response curve: the gap between a recreational dose and one causing unconsciousness or fatal respiratory depression is small, with no antidote.

Gabapentin (brand names Neurontin, Gralise, Horizant) is a prescription medication approved to treat partial seizures, nerve pain from shingles, and restless legs syndrome, and used off-label for many other conditions. Despite its name it does not act directly on GABA receptors. It is not a federally controlled substance in the U.S., though some states schedule it, and it carries a real but comparatively low risk of misuse and dependence — highest in people with a history of opioid or other substance use.

HHC (hexahydrocannabinol) is a hydrogenated cannabinoid with THC-like intoxicating effects, sold in hemp-derived vapes and edibles. Its safety is poorly studied, product quality is inconsistent, and the 2025 federal hemp law effective November 12, 2026 is expected to make most HHC products federally illegal.

HPPD (hallucinogen persisting perception disorder) is a condition where visual disturbances from a past psychedelic experience — trails, afterimages, halos, geometric patterns, 'visual snow' — keep recurring while completely sober, sometimes long after use. It is recognized in the DSM-5. Genuine chronic HPPD is rare, it is not physically dangerous, but it can be distressing, and there is no reliable cure (though some treatments help).

Heroin is a highly addictive opioid; today's illicit supply is frequently contaminated with fentanyl, making overdose the central danger.

Hydrocodone is a semi-synthetic prescription opioid for moderate-to-severe pain, most familiar in acetaminophen combinations such as Vicodin and Norco, and a Schedule II controlled substance in the US. Like all opioids its defining danger is respiratory depression — magnified by alcohol or benzodiazepines, by lost tolerance after a break, and by fentanyl-contaminated counterfeit pills in the illicit supply.

Detailed, medically-reviewed information for Ketamine is being prepared.

Khat is a flowering plant (Catha edulis) whose fresh leaves are chewed for a mild stimulant effect; its main active compound is cathinone (see the cathinone page for the pharmacology). Chewed traditionally across East Africa and the Arabian Peninsula, khat is legal in some of those regions but is a Schedule I controlled substance in the United States. Its risks are stimulant-type plus route-specific harms from prolonged chewing.

Kratom is a Southeast Asian plant whose leaves act as a mild stimulant at low doses and produce opioid-like effects at higher doses; it carries real dependence and toxicity risks and is federally unscheduled but banned in several U.S. states.

LSA (ergine) is a naturally occurring psychedelic found in morning glory and Hawaiian baby woodrose seeds, structurally related to LSD but milder and often nauseating. In the US the compound is a Schedule III controlled substance, though the seeds themselves are legal to buy; extracting or preparing LSA for consumption is what triggers the law.

LSD is an extremely potent hallucinogen that alters perception for many hours; its dangers are psychological — bad trips, impaired judgment, and rare lasting effects — not overdose.

Lorazepam (Ativan) is a benzodiazepine for anxiety and seizures; it causes dependence, is dangerous with opioids or alcohol, and withdrawal can be dangerous.

MDA (sassafras) is a psychedelic amphetamine closely related to MDMA, producing similar euphoria and empathogenic effects but with stronger psychedelic and stimulant properties and greater neurotoxicity risk. It is a Schedule I controlled substance in the US, and illicit supply is subject to fentanyl and misrepresentation risk.

Detailed, medically-reviewed information for MDMA is being prepared.

MDPV is a synthetic cathinone stimulant and one of the "bath salts" drugs. Unlike releasers such as mephedrone, it is an extremely potent reuptake blocker at dopamine and norepinephrine, cocaine-like but far stronger, and it is linked to some of the most severe toxicity in the cathinone family.

MXE (methoxetamine) is a synthetic dissociative and a chemical relative of ketamine. Like ketamine and PCP it blocks the NMDA receptor, producing dissociative, anaesthetic-like effects that are reported to last longer than ketamine's. It carries real risks of harm and dependence.

Memantine is an FDA-approved prescription medication for moderate-to-severe Alzheimer's disease; it is an NMDA-receptor antagonist with low abuse potential, included here for context alongside the dissociatives it is chemically related to.

Mephedrone (4-MMC) is a synthetic cathinone stimulant chemically related to the khat plant's active compound. It produces MDMA- and cocaine-like effects — euphoria, energy, and sociability — but carries serious risks including sympathomimetic toxicity and a strong urge to redose.

Mescaline is a naturally occurring psychedelic from cacti such as peyote; effects are long-lasting, risks are mainly psychological, and it has protected religious-ceremonial use in the US.

Methadone is a long-acting opioid used to treat opioid addiction and pain; it is effective and life-saving in treatment but dangerous in overdose, especially early in use.

Methamphetamine is a powerful, highly addictive synthetic stimulant that strains the heart and brain and is increasingly contaminated with fentanyl.

Methaqualone (brand name Quaalude, also known as 'mandrax' internationally) is a synthetic sedative-hypnotic central-nervous-system depressant, once prescribed in the 1960s-70s for insomnia and anxiety before widespread abuse led to a U.S. ban. It produces sedation, muscle relaxation, and euphoria similar to barbiturates but with a narrow margin of safety. It has been a Schedule I controlled substance in the U.S. since 1984, with no accepted medical use.

Methylone (bk-MDMA) is a synthetic cathinone and the beta-keto analogue of MDMA. It produces MDMA-like empathogenic and stimulant effects but of lower intensity, and like mephedrone it acts as a monoamine releaser rather than a pure reuptake blocker like MDPV.

Methylphenidate (Ritalin, Concerta) is a prescription stimulant for ADHD and narcolepsy; misuse strains the heart, can cause dependence and psychosis, and is risky combined with other drugs.

Mitragynine is the main active alkaloid in kratom; it acts on opioid and other receptors, converts in the body to the more potent 7-hydroxymitragynine, and carries dependence and opioid-like risks.

Modafinil (Provigil) is a wakefulness-promoting medication for narcolepsy, sleep apnea, and shift-work sleep disorder, widely used off-label as a cognitive enhancer. It is a Schedule IV controlled substance with lower abuse potential than amphetamines, but it is not benign: rare life-threatening skin reactions such as Stevens-Johnson syndrome, cardiovascular and psychiatric effects, and a clinically important interaction that weakens hormonal contraceptives.

Morphine is a strong opioid painkiller derived from the opium poppy; like all opioids it can suppress breathing, cause dependence, and be fatal in overdose.

Nicotine is a highly addictive stimulant found in tobacco and vaping products; it is the main reason tobacco use is so hard to quit, and it raises heart rate and blood pressure while carrying serious dependence and poisoning risks.

Nitrous oxide ('laughing gas') is a short-acting inhaled gas; main dangers are oxygen deprivation, injury from fainting, and nerve/spinal damage from heavy repeated use (B12 depletion).

Oxycodone is a prescription opioid for pain with high addiction and overdose risk; like other opioids it can stop breathing, and counterfeit "oxy" pills frequently contain fentanyl.

PCP ('angel dust') is a dissociative anesthetic that can cause agitation, violent or unpredictable behavior, and dangerous medical emergencies; effects are unpredictable and risky.

Peyote is a small cactus containing the psychedelic mescaline, used for centuries as a sacred sacrament by Indigenous peoples and the Native American Church. Its effects come from mescaline and include strong nausea; its US legal status is notable for a genuine religious-use exemption alongside Schedule I control, and the plant is slow-growing and threatened.

Phenibut is a synthetic GABA-derived central nervous system depressant, prescribed for anxiety and sleep in a few countries but not approved for medical use in the US, where it is sold online as a nootropic supplement despite the FDA ruling it is not a legal dietary ingredient. It is not federally scheduled, but its benzodiazepine-like dependence and severe withdrawal, plus a slow onset that drives dangerous re-dosing, make it far riskier than its supplement reputation suggests.

A pink-dyed street mixture — usually ketamine + MDMA, and rarely 2C-B. See the full pink cocaine guide.

Poppers are alkyl nitrite inhalants (amyl, isopropyl, isobutyl nitrite) used for a brief head-rush and muscle relaxation, notably during sex. Not scheduled under drug law but not FDA-approved for consumption, they are sold via a 'cleaner'/'not for human consumption' loophole. Their signature danger is methemoglobinemia — especially fatal if swallowed rather than inhaled.

Pregabalin (brand name Lyrica) is a prescription gabapentinoid approved to treat neuropathic pain, fibromyalgia, and partial-onset seizures. Structurally related to GABA, it acts on calcium channels rather than GABA receptors. It is a Schedule V controlled substance in the U.S. — the lowest control tier — reflecting a real but relatively low potential for misuse and dependence, which is highest among people with a history of opioid use.

Psilocybin is the psychedelic compound in "magic mushrooms"; effects resemble a shorter LSD trip, risks are mainly psychological, and its U.S. legal status is shifting in a few states.

Quetiapine (Seroquel) is a second-generation antipsychotic for schizophrenia, bipolar disorder, and depression. It is not a controlled substance, but its heavy sedation drives off-label misuse as a sleep aid — a reputation that hides real dangers: QT-prolongation and heart-rhythm risk, metabolic and blood-pressure effects, and compounded respiratory depression when mixed with other CNS depressants.

Salvia divinorum is a plant whose active compound, salvinorin A, is one of the most potent natural hallucinogens; it produces brief but intense, often disorienting dissociative effects through a mechanism unlike other psychedelics, and its legal status varies widely by state.

Scopolamine (hyoscine, 'Devil's Breath') is a prescription anticholinergic and tropane alkaloid used medically for motion sickness and post-operative nausea, most familiar as the behind-the-ear Transderm Scop patch. It is not a DEA-scheduled controlled substance, but it is dangerous: at higher doses it causes disorientation, memory loss, and suggestibility, and it is best known for its use in drug-facilitated crimes via spiked drinks.

Serotonin syndrome (serotonin toxicity) is a potentially life-threatening reaction caused by too much serotonin activity in the brain, usually from combining two or more serotonergic drugs. It's the main reason certain drug combinations are dangerous — especially MDMA, stimulants, or psychedelics mixed with antidepressants (SSRIs, SNRIs) or MAOIs. It ranges from mild to rapidly fatal, and it's a medical emergency.

'Set and setting' is the idea that a psychoactive experience — especially with psychedelics — is shaped as much by the person's mindset ('set') and physical/social environment ('setting') as by the drug itself. It's a core harm-reduction concept: the same substance can produce a meaningful experience or a terrifying one depending on these factors, and ignoring them is a leading cause of bad trips.

'Synthetic cannabinoids' covers two very different things. First, the K2/Spice class of research-chemical cannabinoids (e.g. AMB-FUBINACA) sprayed on plant material — far more dangerous than cannabis, causing seizures, psychosis, and death, and largely Schedule I. Second, hemp-synthesized cannabinoids like delta-8/HHC — milder but in flux under a 2025 law effective November 12, 2026. This page covers both, separately.

THC-P (tetrahydrocannabiphorol) is a cannabinoid that binds the CB1 receptor far more strongly than ordinary THC, making it substantially more potent, and is sold in hemp-derived products. Little is known about its safety, and the 2025 federal hemp law effective November 12, 2026 is expected to make most THC-P products federally illegal.

Tobacco delivers nicotine, one of the most addictive substances known, through cigarettes, cigars, smokeless products, and vapes. It is legal and FDA-regulated with a federal minimum purchase age of 21, but it is the leading cause of preventable death in the US — the deadliest substance in this library by a wide margin, killing through cancer, heart disease, and lung disease rather than acute overdose.

Tolerance is when repeated drug use makes a given dose feel weaker, so more is needed for the same effect. Its most dangerous feature isn't needing more — it's what happens when tolerance drops: after a break (detox, jail, illness), a previously 'normal' dose can become a fatal overdose. Tolerance also drives dependence and cross-tolerance between related drugs.

Tramadol is a prescription opioid painkiller that also affects serotonin; it carries opioid overdose and dependence risk plus added risks of seizures and serotonin syndrome.

Alprazolam (Xanax) is a fast-acting benzodiazepine for anxiety; it causes dependence quickly, is dangerous mixed with opioids or alcohol, and counterfeit "Xanax" pills often contain fentanyl.

Xylazine ("tranq") is a veterinary sedative not approved for human use that has become a widespread adulterant in the illicit fentanyl supply. It is not an opioid and is not reversed by naloxone, and it causes severe, distinctive skin wounds that can lead to amputation. It is central to the question of what street drugs are cut with.

Zolpidem (Ambien) is a prescription sleep medication; it can cause dependence, complex sleep behaviors like sleep-driving, and is dangerous combined with alcohol or other depressants.