Posted on 23 mins read

I am not a doctor and this is not medical advice. Consult your doctor before using any drug.

In the United States, LSD and heroin are in the same controlled substance category (the most restrictive one, Schedule I), placing them a category above amphetamines and fentanyl, two categories above ketamine, and three full categories above alprazolam (Xanax). Tobacco is not a controlled substance at all. I hope to convince you that this is ridiculous—not merely an outdated or insufficiently-nuanced classification system, but one so wrong it can only have been created by rolling dice or throwing darts.

I’m not an alcohol, nicotine, or drug user, so on this subject I’m as unbiased as anyone you’re likely to meet.

The DEA’s controlled substances schedules claim to categorize drugs based on three measures:

  • Medical usefulness
  • Potential for abuse (that is, whether they’re “fun”)
  • Likelihood of causing dependence (“addiction”) when used recreationally

These measures are flattened to a single scale with five categories, from Schedule I to Schedule V, which is the source of several problems. For example, a reasonable person would assume that LSD, being a Schedule I drug, is extremely addictive or dangerous, and that Phenergan with Codeine, being a Schedule V drug, is only a little addictive or dangerous. But the opposite is true:

To recap: a drug that won’t kill you or cause dependence is categorized as Schedule I, the DEA’s most restrictive drug schedule. And a drug that kills hundreds to thousands of people per year, a literal opioid, can be obtained in some formulations as a Schedule V drug, the least restrictive drug schedule.

Pure codeine is a Schedule II drug and some other codeine formulations are Schedule III. However, Phenergan with Codeine is the formulation most known for recreational use; you might have heard it referred to in popular music by the slang terms “lean,” “purple drank,” or “sizzurp."

The DEA’s likely rationale for this is that LSD has no approved medical use, whereas codeine can be used for pain management. Never mind that it’s been illegal to study LSD’s medical uses for most of the last 50 years, leaving it caught in a double-bind, and never mind that pharmaceutical companies have been caught red-handed—to the tune of billions of dollars in legal settlements—pumping American homes full of opioids, causing a substance use epidemic that has claimed the lives of hundreds of thousands. Never mind that most of the things we consume have no approved medical use. Never mind that peanuts take more lives than LSD.

In the last few years the government has been more permissive of research into hallucinogens. LSD and other hallucinogenic drugs have shown very promising results in the treatment of depression, PTSD, substance use disorders, and other mental health conditions. In time this could lead to them being rescheduled and available for prescription use.

LSD does, of course, cause temporary hallucinations. I’ll leave it to you to figure out why the DEA thinks you shouldn’t be allowed to hallucinate.

Such massive gaps in public understanding of psychoactive drugs are not limited to LSD and codeine. They’re not even limited to the DEA’s controlled substance schedules. The federal government’s War on Drugs has been a resounding failure from top to bottom (and explicitly racist in its motivations). Perhaps the least of its crimes is propagating the idea that all drugs belong to two categories: dangerous, life-destroying “illegal” drugs, and safe, medically-beneficial “legal” drugs.

Caffeine is legal. Psilocybin (the psychoactive compound in magic mushrooms) is illegal. Marijuana is kind of legal, depending on your location. Do you know which one is most likely to kill someone you care about? Do you know which one is most addictive? Most Americans don’t. The government has intentionally and repeatedly published such poor information on the subject that we can’t be expected to know. And a Google search isn’t likely to help; nearly all searches involving illicit drugs or addiction return a government addiction hotline number and an endless list of addiction treatment center websites, all of which offer bland platitudes, warnings, and marketing materials in place of useful information.

Sadly, the addiction treatment industry in America has profound ethical problems and often does more harm than good to people seeking help.

So what would better information look like?

A system for categorizing drugs

Before we look at drugs on a case-by-case basis, we should agree on a way to compare them.

One scholarly framework for rating the addictiveness of a drug considers five criteria:

  1. Withdrawal: The negative physical symptoms suffered when a habitual user stops taking the drug.
  2. Tolerance: The user’s desire for, and ability to handle, higher doses over time.
  3. Reinforcement: The positive effects experienced when the drug is used, which encourage repeated use.
  4. Dependence: The proportion of users who develop a substance use disorder.
  5. Intoxication: The user’s level of impairment while the drug is active.

I bring this up only to point out that “addictiveness” can’t be reduced to a single scale. There’s an unreliable correlation, for example, between how “high” a drug gets you (reinforcement) and how likely you are to use it habitually or be unable to quit (dependence). Cigarettes, as a case in point, give only a mild sense of satisfaction (users rate them less pleasurable than other drugs) but have been named the third most addictive drug in the world and are the most prevalent addiction worldwide: 22.5% of adults smoke, with only 5% of smokers able to quit on a given attempt and 50% remaining addicted regardless of number of attempts. Even light smokers typically meet the criteria for addiction. There’s very little “high per unit of addiction,” so to speak.

It’s been claimed that cigarettes are “as addictive as cocaine and heroin”, but this claim is highly reductive and seems to stem from a gross misreading of a 1988 report by the Surgeon General which stated only that “the pharmacologic and behavioral processes that determine tobacco addiction are similar to those that determine addiction to drugs such as heroin and cocaine."

On the other hand, psilocybin pretty reliably (albeit not always) produces a pleasant feeling, and its effects last 4 to 8 hours, at least twice as long as nicotine. It’s not known to be addictive—users commonly take it very infrequently, going years between doses—and in fact its only correlation with addiction is that it shows promise in helping people quit tobacco. We can’t measure the “high per unit of addiction” because it’s impossible to divide by zero.

There’s a lot of complexity here, but it’s not the whole story; addiction isn’t the only thing we care about. When it comes to our loved ones and neighbors, it’s even more important to consider a drug’s physical risks: can it cause death by overdose? What about permanent brain or organ damage? Do its users become violent or reckless? We want the people we care about to be free of addiction, but more than that we want them to be alive.

A useful categorization system for drugs would include all of the above. I propose the following criteria:

  • Overdose Risk. Is this drug potentially lethal? If so, how much risk are users subject to? For drug-to-drug comparison, I’ll take the number of reported overdose deaths per year divided by the estimated total number of users, then multiply by 10 to represent the risk of repeated long-term use. Higher values mean a higher risk of overdose.
  • Dose Sensitivity. What’s the difference between a recreational dose and a lethal dose? If a user is measuring their own dose, what’s the risk of accidental overdose? For an estimate, I’ll take 5 grams (the smallest weight that can be accurately measured by a cheap food scale) divided by the difference of the effective dose and the estimated lethal dose. A value of 1 means that a user can can probably avoid unexpected doses when measuring an unadulterated drug on a food scale. Higher values indicate greater difficulty in measuring the desired dose.
  • Risks. What negative health effects are known to be caused by recreational use of this drug? Secondary risks, such as car accidents caused by intoxicated driving or social exclusion from drug-stigmatizing communities, are not considered.
  • Dependence. Is this drug addictive? If so, what proportion of users become dependent? Scholars are divided on what constitutes addiction and how to measure it, so general terms such as “Low,” “Moderate,” “High,” and “Severe” will have to do.
  • Withdrawal. How intense and long-lasting are physical withdrawal symptoms when a habitual user quits using the drug? Symptomatic terms can be useful here as each drug tends to have a unique withdrawal profile. I’ll summarize these as, for example, “Chills, irritability — weeks” or “Fatigue, organ failure — years”. Note that this doesn’t include psychological withdrawals or cravings, which may continue for several times as long.
  • Intoxication. Does this drug impair the user while active? If so, how badly (in the worst case) and to what end? Many drugs make it unsafe to drive, but few are associated with violent behavior as strongly as alcohol. I’ll classify intoxicant effects from “Mild” to “Severe” and indicate whether violence has been documented.
  • Recommendation. A final recommendation as to whether this drug should be freely available over the counter or targeted by harm-reduction strategies.

An overview of common drugs

Now allow me to re-introduce you to several drugs, some of which you’ve almost certainly used before, some of which you may someday use (by prescription or otherwise), and some of which you may never use.

The information below may be incomplete or go out of date as new research is published, and is only relevant to each drug in isolation. Using multiple drugs simultaneously is far more dangerous and unpredictable. If you find any inaccuracies, please contact me.

I am not a doctor. The drugs below, and other drugs, should only be taken as prescribed by your doctor. For harm reduction advice on a variety of drugs, see

Anabolic steroids (testosterone and derivatives) - Athletic performance enhancer

Schedule III

Lethal Overdose Risk: 0

Dose Sensitivity Factor: 0.14

Long-term Risks: Heart attack, hypertension, kidney failure, coronary artery disease, heart disease, cancer (kidney, prostate), liver disease, arrhythmia, sexual dysfunction, sex organ atrophy, acne, baldness, infertility, fetal toxicity, muscle hypertrophy, immune dysfunction, glucose resistance, insulin resistance, growth defects.

Immediate Risks: Aggression, mood swings, psychosis, increased risk of suicide.

Dependence: High

Withdrawal: Depression, anxiety, fatigue, sleep problems — weeks

Intoxication: Mild, can be violent

Recommendation: Educate users on the long-term risks of steroid use. Provide domestic violence resources to affected communities.

Benzodiazepines (Xanax, Valium, Klonipin) - Depressant

Schedule IV

Lethal Overdose Risk: 0.02%

Alprazolam (Xanax) is more likely to cause death by overdose than other drugs in this category.

Dose Sensitivity Factor: Unknown

Each benzodiazepine has a different clinical dose, typically below 1mg. However, the lethal dose of each is not clearly defined because tolerance varies so much between individuals. The majority of benzodiazepine-involved overdoses also involve opioids.

Long-term Risks: Brain damage, cognitive impairment, worsened sleep and sleep disorders, depression, anxiety disorders, psychosis, hallucinations, sexual dysfunction, neurocognitive disorders, irritable bowel syndrome, panic attacks, increased risk of pneumonia, increased risk of suicide, cancer (brain, lung, bowel, bladder, breast).

Immediate Risks: Drowsiness, dizziness, difficulty concentrating, lack of coordination, hypotension, hypoventilation, depression, erectile dysfunction.

Dependence: Moderate

Withdrawal: Nausea, diarrhea, vomiting, suicidal ideation, convulsions, hypertension, tachycardia, hallucinations, OCD, PTSD, depression, blurred vision, paranoia, aphasia, dry retching, insomnia, restless legs syndrome, mood swings, irritability, anxiety, panic attacks, tremors, sweating, difficulty concentrating, confusion, cognitive impairment, memory problems, palpitations, headache, muscle pain/spasms/stiffness, chest pain, dizziness, dysphoria, fatigue, hot and cold spells, aggression — weeks to years

Intoxication: Severe, may or may not be violent

Notes: Benzodiazepine withdrawals are famously intense, with up to 15% of users experiencing significant withdrawal symptoms for longer than a month. In rare cases symptoms can persist for a decade or more.

Recommendation: Prescribe benzodiazepines only as a last resort; educate patients on the risks of withdrawal.

Caffeine — Stimulant

Unrestricted | food/drink additive

Lethal Overdose Risk: 0.00000005% (effectively zero)

Dose Sensitivity Factor: 0.5

Long-term Risks: None (most studies find health benefits from moderate daily caffeine use)

Immediate Risks: Anxiety, jitters, difficulty sleeping.

Dependence: None

Withdrawal: Headache, irritability, fatigue, low mood, difficulty concentrating — 24 hours

Intoxication: Mild, nonviolent

Notes: Cases of caffeine overdose, especially in teens, tend to get widespread media coverage but are in fact extremely rare. Deaths involving energy drinks may be complicated by other ingredients with less well-studied effects.

Recommendation: Keep unrestricted. Study other common ingredients in energy drinks for possible risks and interactions.

Cannabis (marijuana) — Mixed effect drug

Schedule I | legality varies by state

Lethal Overdose Risk: 0 (no recorded deaths by overdose)

Dose Sensitivity Factor: 0

Long-term Risks: Inhibited brain development, psychosis, schizophrenia, reduced brain function, hyperemesis (vomiting) syndrome, lung cancer (only when smoked), infertility, fetal toxicity.

Immediate Risks: Tachycardia, heart attack, anxiety.

Dependence: Moderate

Withdrawal: Irritability, insomnia, discomfort — days

Intoxication: Moderate to severe, may or may not be associated with violence

Notes: The risks of cannabis are higher in adolescence than adulthood, but on the whole it’s significantly safer and less addictive than most other drugs, including alcohol.

Recommendation: Legalize for recreational use. Educate consumers on long-term health risks.

Cocaine — Stimulant, anesthetic

Schedule II | rarely prescribed outside of surgery

Lethal Overdose Risk: 0.05%

Dose Sensitivity Factor: 5.56

Long-term Risks: Lung trauma, blood disorders, asthma, headaches, nausea, heart attack, stroke.

Immediate Risks: Dysrhythmia, arrhythmia, tachycardia, hypertension, hypotension, heart attack, anxiety, paranoia, confusion, nausea, vomiting, seizure.

Dependence: High. Risk of dependence increases substantially with repeated use and is highest when taken in free-base form (crack) or injected

Withdrawal: Exhaustion, irritability, anxiety, mood swings, depression, poor concentration, bowel issues, dysphoria — months

Intoxication: Severe, can be violent

Notes: Cocaine is the most commonly adulterated drug. It’s often cut with fentanyl, which is far more toxic, and levamisole, which may cause autoimmune disesase.

Recommendation: Reduce harms by providing supervised consumption sites, adulterant test strips, naloxone (for cases of opioid contamination), and domestic violence resources.

Diphenhydramine (Benadryl) — Allergy reliever

Unrestricted | over the counter

Lethal Overdose Risk: Unknown

There are over 1,600 antihistamine-involved overdose deaths per year, but it’s uncertain how many people use them recreationally. Overdoses typically occur in users who mix antihistamines with other drugs or knowingly take supraclinical doses daily for multiple weeks.

Dose Sensitivity Factor: 5.26

Since this drug is available over the counter, dosing accidents are rare.

Long-term Risks: None

Immediate Risks: Coma, seizure, cardiac arrhythmia.

Dependence: Low (recreational use is common, but physical dependence is rare)

Withdrawal: Psychosis, tremors, tachycardia — days

Intoxication: Mild, nonviolent

Notes: Diphenhydramine is often present in overdose deaths but rarely is it the only drug, or even the primary drug, responsible for the overdose.

Recommendation: Keep unrestricted. Warn consumers that excessive intake can be fatal.

N,N-Dimethyltryptamine (DMT) — Hallucinogen

Schedule I | illegal to possess

Lethal Overdose Risk: 0

When ingested, e.g. in the form of ayahuasca, vomiting and/or diarrhea are normal and expected parts of the experience. This reduces the risk of overdose by ejecting the drug from the body. However, there appear to be no documented cases of DMT overdose death regardless of the mode of use.

Dose Sensitivity Factor: 26.32 or lower

Long-term Risks: Hypertension, potential to trigger latent psychological disorders.

Immediate Risks: Paranoia, anxiety, panic attacks.

The immediate risks of hallucinogen consumption can be substantially alleviated by taking a moderate dose and preparing one’s mind and environment.

Dependence: None documented

Withdrawal: None documented

Intoxication: Severe, may reduce violence

Notes: DMT is the main psychoactive ingredient in many preparations of ayahuasca, a South American ceremonial drink. N,N-Dimethyltryptamine (usually just called DMT) shouldn’t be confused with 5-methoxy-N,N-dimethyltryptamine (called 5-MeO-DMT), which is more potent and has different subjective effects, though it is also considered safe and unlikely to cause dependence.

Recommendation: Legalize; regulate ingredients and doses as an over-the-counter drug.

Ethanol (Any alcoholic beverage) — Depressant

Unscheduled | restrictions vary by age and location

Lethal Overdose Risk: 0.00013%

Dose Sensitivity Factor: 0.84

Long-term Risks: Cancer (esophageal, mouth, tongue, liver, colorectal, breast), pancreatitis, gastritis, ulcers, hypertension, dementia, heart disease, liver disease, nerve damage, DNA damage, erectile dysfunction, fetal disorders.

Immediate Risks: None

Dependence: Moderate (90% of drinkers aren’t dependent, but alcohol use is so common that alcohol dependence is widespread anyway)

Withdrawal: Nausea, headache, hallucination, seizure, fever, hypertension, tachycardia, delirium — days

Intoxication: Severe, can be violent

Notes: Over 5% of all deaths each year are estimated to be caused by alcohol. However, it’s hard to draw meaningful conclusions from this statistic because alcohol is consumed far more than any other drug—in some countries, nearly 80% of adults are drinkers.

Recommendation: Reduce harms by encouraging moderation and providing domestic violence resources. Educate consumers on long-term health risks.

Ketamine - Dissociative anesthetic

Schedule III

Lethal Overdose Risk: 0.001%

Dose Sensitivity Factor: 7.72

Long-term Risks: Kidney failure, liver damage, gallstones, cachexia, gastrointestinal disease, hepatobiliary disorder, bladder infection, hydronephrosis, dissociation, depression, delusion, memory deficits, cognitive impairment.

Immediate Risks: Dizziness, blurred vision, hypertension, hallucination, dysphoria, delirium, nausea, vomiting, aphasia, confusion, drowsiness, difficulty concentrating, psychosis, changes in body temperature.

Dependence: Unknown, possibly severe

Withdrawal: Anxiety, depression, fatigue, sweating, shaking, palpitations — days

Intoxication: Severe, nonviolent

Recommendation: Study the risk of ketamine dependence; provide supervised consumption sites.

Lysergic acid diethylamide (LSD, acid) - Hallucinogen

Schedule I | illegal to possess

Lethal Overdose Risk: 0

Dose Sensitivity Factor: 50.03

The lethal dose of LSD is (theoretically) several hundred times the usual recreational dose.

Long-term Risks: Flashbacks, potential to trigger latent psychological disorders.

Immediate Risks: Anxiety, panic attacks, self-endangering behavior.

The immediate risks of hallucinogen consumption can be substantially alleviated by taking a moderate dose and preparing one’s mind and environment.

Dependence: None

Withdrawal: None

Intoxication: Severe, nonviolent

Notes: Designer drugs are often passed off as LSD by drug dealers. These are toxic and can cause fatal overdoses. It may be possible to detect them from a bitter or metallic taste or numbness in the tongue.

Recommendation: Legalize; regulate ingredients and doses as an over-the-counter drug.

MDMA (ecstasy, molly) - Psychedelic stimulant

Schedule I | illegal to possess

Lethal Overdose Risk: 0.00018%

Dose Sensitivity Factor: 15.625

Long-term Risks: Depression, brain damage, cognitive impairment, impulsivity, inflammation.

Immediate Risks: Hyperthermia, dehydration, hyponatremia, coma, internal hemorrhage, hepatitis, kidney damage, teeth grinding, diarrhea, erectile dysfunction, insomnia, tachycardia, hypertension, nausea, vomiting, fatigue, anxiety, depression, paranoia, psychosis, hallucination, anhedonia, lockjaw, irritability, impulsiveness, DNA damage, memory impairment, fetal toxicity.

Some of the most common immediate risks of MDMA can be averted by drinking plenty of water and electrolytes.

Dependence: Low

Withdrawal: Fatigue, loss of appetite, depression, anxiety, difficulty concentrating — days

Intoxication: Severe, may be violent

Notes: MDMA is notable for its high and long-lasting tolerance effect—it stops “working” if taken more than once a month, and causes a buildup of tolerance (which may be permanent) even with infrequent use. This discourages the compulsive use often seen with other stimulant drugs. Sometimes MDMA is categorized as a hallucinogen, but its safety and dependence profile is much worse than other hallucinogens.

Recommendation: Reduce harm by providing supervised consumption sites. Educate users on the importance of hydration and waiting several weeks or months between doses.

Methamphetamine (meth) — Stimulant

Schedule II | rarely prescribed

Lethal Overdose Risk: 0.26%

Dose Sensitivity Factor: 29.41

Long-term Risks: Parkinson’s Disease, brain damage, psychosis, cognitive impairment, skin sores.

Immediate Risks: Psychosis, irregular heartbeat, hypertension, hypotension, tremors, diarrhea, constipation, headache, severe itchiness, dry mouth, teeth grinding, paranoia, fetal neurological disorders.

Dependence: Extremely severe. Highest when injected.

Withdrawal: Depression, anxiety, irritability, paranoia, fatigue, suicidal ideation, insomnia and hypersomnia — weeks

Intoxication: Severe, can be violent

Notes: Meth is second only to fentanyl in overdose deaths.

Recommendation: Reduce harms by providing supervised consumption sites, adulterant test strips, and domestic violence resources.

Nitrous oxide (laughing gas, whippets) — Dissociative anesthetic

Unscheduled | FDA regulated | legal to purchase for non-recreational purposes

Lethal Overdose Risk: Unknown, likely very low

As nitrous oxide is an inhalant, it’s difficult to distinguish between death by toxic overdose and death by hypoxia (suffocation). Toxicity without hypoxia is thought to be possible in extreme cases.

Dose Sensitivity Factor: Unknown

Long-term Risks: Paralysis, spinal nerve damage, neuropathy, anemia, numbness, stroke, vitamin B12 deficiency, fetal toxicity.

Immediate Risks: Hypoxia, dizziness, weakness, delirium, panic attacks, irritability, tachycardia, hypertension, chest pain.

Dependence: Very low, possibly none

Withdrawal: None documented

Intoxication: Severe, unknown if violence is associated

Notes: The most severe long-term effects of nitrous oxide use may be alleviated by vitamin B12 supplementation, but regardless of the amount of supplementation, functional B12 deficiency may still occur. Industrial-grade and even food-grade nitrous oxide have contaminants that may not be safe to inhale.

Recommendation: Legalize recreational use and regulate ingredients as an over-the-counter drug so contaminant risks can be eliminated. Educate users on the risk of functional B12 deficiency and long-term nerve damage.

Opioids — Narcotics, pain relievers

Opioids as a group have similar risk, dependence, withdrawal, and intoxication profiles. Any significant differences are indicated below.

Schedule I: heroin

Schedule II: fentanyl, oxycodone (OxyContin/Percocet), morphine, opium, hydrocodone (Vicodin, Lortab), hydromorphone (Dilaudid), codeine

Schedule III: Mid-concentration codeine formulas (Tylenol with Codeine), buprenorphine (Suboxone)

Schedule V: Low-concentration codeine formulas (Robitussin AC, Phenergan with Codeine)

Lethal Overdose Risk: 0.08% across all opioids — as high as 8% for heroin specifically — as high as 16% for fentanyl specifically

Opioids are typically studied as a group, but small studies have found that as many as 4% of fentanyl injections and 2% of heroin injections cause an overdose.

Dose Sensitivity Factor: Fentanyl 2,631.57 / Heroin 26.59 / Morphine 20.83 / Codeine 20

The Fentanyl value is not a typo. The difference between a recreational dose and a lethal dose is miniscule, roughly the weight of a snowflake or a postage stamp.

Long-term Risks: Heart attack, lowered testosterone, erectile dysfunction, infertility, abnormal pain sensitivity, fatigue, depression, decreased muscle mass, osteopenia, osteoporosis, immune dysfunction, pneumonia, hypotension, pulmonary edema, fainting, irregular heartbeat, impaired sleep, sleep disorders.

Immediate Risks: Respiratory failure, nausea, vomiting, constipation, drowsiness, confusion, weakness, abdominal pain, headache, fatigue, anxiety, depression.

Dependence: Severe

Opioids as a group cause dependence at an extremely high rate. The specific addiction risk of fentanyl is unknown, but thought to be higher than other opioids due to its potency.

Withdrawal: Tachycardia, diarrhea, vomiting, sweating, aches, runny nose, crying, tremors, anxiety, irritability — days

Intoxication: Severe, may or may not be associated with violence

Notes: Fentanyl is by far the most prolific cause of drug overdose death. This is because its potency at low doses makes it more profitable to import but also more difficult to portion correctly. The vast majority of fentanyl users do not know they’re using it because it’s a common adulterant in drugs like cocaine and heroin.

Recommendation: Devote extraordinary resources to reducing harms by providing fentanyl test strips, naloxone, and supervised consumption sites.

Phencyclidine (PCP, angel dust) - Dissociative anesthetic

Schedule II | discontinued for medical use

Lethal Overdose Risk: Unknown; no less than 0.02%

PCP is very infrequently used compared to other recreational drugs, so data on overdose deaths is sparse. Data suggests that it may pose a substantial overdose risk.

Dose Sensitivity Factor: 208.33

Long-term Risks: Memory loss, aphasia, depression, psychosis, anxiety.

Immediate Risks: Seizures, coma, delirium, convulsions, numbness, loss of balance and coordination, paranoia, psychosis, agitation, dysphoria, hallucination, blurred vision, suicidal impulses.

Dependence: Unknown; probably moderate to low

Withdrawal: Anxiety, irritability, dysphoria — days

Intoxication: Severe, probably nonviolent

Sensationalized media reports of violent behavior in PCP users are not representative of the typical user.

Notes: PCP is often characterized as a hallucinogen, having a better safety profile than other classes of drugs, but it does appear to be less safe than other hallucinogens.

Recommendation: Reduce harms by providing supervised consumption sites.

Pseudoephedrine (Sudafed) — Decongestant

Over the counter | individual purchase amounts restricted

Lethal Overdose Risk: Unknown

Pseudoephedrine overdose deaths are uncommon. 615 were reported in the US between 2010 and 2017, most of which also involved other drugs.

Dose Sensitivity Factor: 20.83

Long-term Risks: Unknown

Immediate Risks: Coma, circulatory collapse, stroke, insomnia, hallucinations, convulsions, tremors, difficulty concentrating, headache, dizziness, anxiety, blurred vision, chest pain, tachycardia, palpitations, abnormal blood pressure, nausea, vomiting.

Dependence: Unknown; may be similar to amphetamines

Withdrawal: Depression — days

Intoxication: Mild, unknown if violence is associated

Notes: Sudafed sales are restricted because it can be used as a precursor ingredient to methamphetamine. It is sometimes used as a recreational stimulant or performance-enhancing drug.

Recommendation: Study the prevalence and effects of recreational use to discover potential harms.

Psilocybin (magic mushrooms/shrooms) — Hallucinogen

Schedule I | illegal to possess

Lethal Overdose Risk: 0

Dose Sensitivity Factor: 0

Long-term Risks: None

Immediate Risks: Panic attack, vomiting, delirium.

The immediate risks of hallucinogen consumption can be substantially alleviated by taking a moderate dose and preparing one’s mind and environment.

Dependence: None

Withdrawal: None

Intoxication: Severe, nonviolent

Notes: Psilocybin has been named the safest recreational drug. There have been no confirmed deaths by overdose. The greatest risk associated with this drug is mushroom misidentification—mistaking a poisonous mushroom for a psilocybin mushroom.

Recommendation: Legalize; regulate ingredients and doses as an over-the-counter drug.

Tobacco (nicotine) — Stimulant

Unscheduled | restricted only by age

Lethal Overdose Risk: 0

Dose Sensitivity Factor: 0.01

This value is as high as 10.02 for pure nicotine, but nicotine is almost always consumed in the form of tobacco, which is about 1% nicotine by weight.

Long-term Risks: Heart attack, stroke, coronary heart disease, COPD, emphysema, cancer (lung, kidney, esophagus, larynx, mouth, bladder, pancreas, stomach, penis, cervix), kidney disease, type 2 diabetes, hypertension, erectile dysfunction, peripheral artereal disease, pneumonia, periodontitis, miscarriage, fetal risks (premature birth, low birth weight, SIDS).

Immediate Risks: None

Dependence: Extremely severe. (Most addictive when smoked.)

Withdrawal: Irritability, jitteriness, dry mouth, tachycardia — weeks

Intoxication: Mild, nonviolent

Notes: Tobacco is the single greatest cause of preventable death worldwide.

Recommendation: Ban tobacco advertising and lobbying. Reduce convenience of access to tobacco products and increase access to medication-assisted cessation programs.

Summary findings

The data above indicate that the safest recreational drugs for short-term and long-term use are caffeine, psilocybin, DMT, and LSD, followed by nitrous oxide and marijuana. All but caffeine and nitrous oxide are Schedule I controlled substances. There’s no rational justification for banning these drugs, and doing so causes harms that could be eliminated by selling them over the counter with regulated ingredients and doses.

The most dangerous recreational drugs in terms of overdose liability are opioids (Schedule I to Schedule V) and methamphetamine (Schedule II). Fatal opioid overdoses could be massively reduced with greater availability of fentanyl test strips, supervised consumption sites, and naloxone. Long-term health burdens associated with opioids could be all but eliminated if a legal supply of “clean” opioids, such as through a Medication-Assisted Treatment program, were readily available. Supervised consumption sites and fentanyl test strips would be valuable for reducing methamphetamine mortality as well, though there is no antidote for methamphetamine overdose.

The drugs most likely to cause dependence are opioids, methamphetamine (Schedule II), and nicotine (unscheduled). Recent efforts to study dependence in terms of Substance Use Disorders (SUDs) with well-defined epidemiology have uncovered several highly-effective treatment methods that allow people affected by severe SUDs to return to work and lead normal lives. The criminalization of SUDs is not effective at deterring or reducing recreational substance use.

Across several drugs, the greatest harms are caused by adulteration (the presence of unexpected chemicals in a drug). It’s impossible to regulate the ingredients of illegal recreational drugs, which makes no-tolerance government policies ineffective in the face of crises like the fentanyl overdose epidemic, which claims over 50,000 lives per year.

Some rules of thumb

For my friends who use, I want to suggest a few simple guidelines:

  1. Never use alone. Have someone in the room with you who knows what you’re doing. If that isn’t possible, call a friend or family member and tell them where you are and what you’re using, then keep them on the line until the possiblity of overdose has passed. If you lose consciousness, it’s important to get medical attention as soon as possible.
  2. Keep naloxone nearby and visible. Naloxone can reverse an opioid overdose. You can get naloxone from the pharmacy without a prescription. It’s free through some state programs and covered by health insurance, Medicare, and Medicaid. If you’re unable to get it for free, a box with two doses will cost $25 to $75 USD. Narcan is administered as a nasal spray; instructions are available here.
  3. Test for fentanyl. There may be Fentanyl Test Strip (FTS) distribution programs available through your city or state. You can also buy them online for a few dollars each.
  4. Talk to someone. Drug dependence can be a painful experience, especially in communities that stigmatize drug use. Find someone to talk to about it. You deserve to be heard, appreciated, and loved whether or not you use drugs.