Lethal Dose Ratio (how many effective doses to kill)
Ratio of estimated lethal dose to effective dose. Source varies by substance; the detail drawer shows the citation when available. Log scale. † = estimate note present.
Fentanyl~1:1†
Opioids6:1
Poppers8:1
GHB8:1
Meth10:1
DXM10:1
Alcohol10:1
Cocaine15:1
MDMA16:1
Mescaline24:1†
Ketamine38:1†
DMT~50:1†
MPH>50:1†
Nicotine50:1
Caffeine100:1
Nitrous>150:1
LSD1,000:1†
Mushrooms1,000:1†
Cannabis>1,000:1†
● <15x● 15-30x● 30-100x● 100x+† estimate note
How Addictive? (estimated likelihood of dependence)
Solid bars: lifetime probability of dependence (Lopez-Quintero 2011, Anthony 1994). Dashed bars: clinical estimates, timeframes vary.
Nicotine~68%
Meth~52%*
Alcohol~23%
Opioids~23%
Fentanyl~23%*
Cocaine~21%
Kratom~15%*
Tramadol~10%*
Cannabis~9%
Benzos~9%*
Ketamine8.5%*
Amfeta8%
Caffeine8%*
MPH~5%*
PCP~5%*
DXM~3%*
GHB~2%*
2C-x<1%*
MDMA~1%*
Nitrous~1%*
Poppers<1%*
█ measured┆ estimated*░ lifetime
Withdrawal Danger
Medical danger (bar fill) vs subjective severity (amber marker). Only three drug classes can directly kill through withdrawal: alcohol, benzodiazepines, and GHB.
Alcohol
GHB
Benzos
Tramadol
Fentanyl
Opioids
PCP
Meth
Cocaine
Ketamine
DXM
MPH
Nicotine
Kratom
Cannabis
Amfeta
MDMA
Caffeine
LSD
Mushrooms
DMT
Mescaline
2C-x
Nitrous
Poppers
■ Medical danger| Subjective severity
How Pure Is It? (% tests as expected)
Data from drug checking services in US, Canada, NZ, and Europe.
Opioids2%
Fentanyl50%
Benzos60%
PCP70%
2C-x74%
MDMA74%
Kratom75%
Ketamine78%
GHB85%
Cocaine88%
Meth88%
DMT90%
Poppers90%
Tramadol90%
Amfeta91%
Mescaline95%
MPH95%
DXM95%
LSD98%
Cannabis98%
Mushrooms99%
Nicotine99%
Nitrous99%
Alcohol99%
Caffeine99%
SSRIs100%
MAOIs100%
Total Damage (to you + to society)
Solid bars: Nutt et al. (Lancet 2010) — 20 substances scored by expert panel. Dashed bars: estimated by OpenSubstance based on clinical literature.
Fentanyl90
Alcohol72
Opioids55
Meth33
Cocaine27
Nicotine26
Amfeta23
Cannabis20
PCP20*
GHB18
Tramadol18*
MPH15*
Ketamine15
Benzos15
Kratom12*
DXM10*
MDMA9
2C-x8*
LSD7
Mescaline6*
Nitrous6
Mushrooms5
DMT5
Poppers5
Caffeine3*
█ Nutt 2010┆ Estimated*
Risk Margin (worst-case doses before physical danger)
Worst case: mixing, unknown supply, preexisting conditions.
● <2x● 2–4x● 4–8x● 8x+
Cocaine1x
PCP1x
DXM1x
Benzos1x
Opioids1x
Fentanyl1x
MDMA1.5x
GHB1.5x
2C-x2x
Meth2x
Ketamine2x
Alcohol2x
Tramadol2x
Kratom2x
Amfeta3x
MPH3x
Nicotine3x
Caffeine5x
Nitrousnote
Poppersnote
LSDsafe
Mushroomssafe
DMTsafe
Mescalinesafe
Cannabissafe