Opioid · morphinan
Heroin
aka Diamorphine · Diacetylmorphine · H · Smack · Brown · China White · Dope · Boy
Last verified
This page is here because pretending heroin doesn't exist in harm-reduction writing doesn't help the people who use it. If you are someone who has been using for a long time, you already know more about this than any web page. If you are someone considering it, the most important sentence on this page is the next one.
The thing that kills heroin users is not heroin, it is heroin that turns out not to be heroin. Across Europe, North America and Australia, fentanyl and its analogues (carfentanil, brorphine, nitazenes) are now showing up in heroin sold as heroin. They are 50–10,000× more potent. A "normal" line of what looks like brown can stop breathing in two minutes. Fentanyl test strips cost about €1, take 30 seconds, and have changed mortality numbers wherever they've been distributed at scale.
Harm reduction
- Always test the bag. Fentanyl strips first, every batch, every supplier. A reagent kit for heroin presence and a strip for fentanyl analogues are not alternatives — you need both.
- Naloxone (Narcan) lives in your bag, not in a drawer. Two doses minimum. If you carry it and you live with or near other people who use, you will save a life — yours or theirs. It works on fentanyl, but you may need more doses and they may need a CPR-trained friend until paramedics arrive.
- Never use alone. "Never use alone" hotlines exist for this exact reason. they stay on the line while you use and call for help if you stop responding. In the US: 1-800-484-3731. In Canada: 1-888-688-NORS. Europe-wide: contact your local user union (Correlation in NL, INPUD globally).
- Recovery position. If somebody is breathing but unresponsive, on their side, head supported, mouth tilted down. Stay until they are talking and standing.
- The lethal combinations are downers. Benzodiazepines, alcohol, GHB/GBL, gabapentin/pregabalin, barbiturates: these stack respiratory depression with heroin. Most opioid deaths in Europe involve polysubstance use, not pure heroin.
- Tolerance resets fast. Three days of abstinence; illness, jail, detox attempt; drops your tolerance significantly. The dose that was fine a week ago will put you in the morgue. Halve it. Halve it again if you've been out for two weeks.
- If you inject: sterile water, fresh needle every time, alcohol swab, rotate sites, never share filters or cookers, count the seconds it takes to push. Pharmacies in most European countries dispense needles free.
- If you're trying to stop: opioid-substitution therapy (methadone, buprenorphine/Subutex/Suboxone) is the most-evidenced treatment in medicine. It is not "swapping one drug for another", it is the difference between living and not. Your GP or any addiction service can refer you.
- For families and friends: carry naloxone. Take the 20-minute training. The person you are most worried about probably won't ask for it; just have it on you.
If you are reading this because someone you love uses, the SAMHSA/EMCDDA harm-reduction position has been the same for thirty years: connection, dignity, supplies that keep them alive long enough for things to change.
Dosage.
Insufflated
- Threshold
- 5 mg
- Light
- 5–15 mg
- Common
- 15–30 mg
- Strong
- 30–50 mg
- Heavy
- 50 mg
Smoked
- Threshold
- 5 mg
- Light
- 5–10 mg
- Common
- 10–30 mg
- Strong
- 30–50 mg
- Heavy
- 50 mg
Intravenous
- Threshold
- 2 mg
- Light
- 2–7 mg
- Common
- 7–15 mg
- Strong
- 15–30 mg
- Heavy
- 30 mg
| Route | Threshold | Light | Common | Strong | Heavy |
|---|---|---|---|---|---|
| Insufflated | 5 mg | 5–15 mg | 15–30 mg | 30–50 mg | 50 mg |
| Smoked | 5 mg | 5–10 mg | 10–30 mg | 30–50 mg | 50 mg |
| Intravenous | 2 mg | 2–7 mg | 7–15 mg | 15–30 mg | 30 mg |
Start at the bottom. Body chemistry, tolerance, and combinations all matter.
Duration.
Insufflated
total ~ 610 min- Onset
- 3–10 min
- Peak
- 60–120 min
- Offset
- 2–4h
- After
- 2–4h
Smoked
total ~ 513 min- Onset
- 0–3 min
- Peak
- 45–90 min
- Offset
- 2–3h
- After
- 2–4h
Intravenous
total ~ 541 min- Onset
- 0–1 min
- Peak
- 60–120 min
- Offset
- 2–3h
- After
- 2–4h
Effects.
Positive
- Profound warmth and physical relief
- Anxiolysis, "all is well" feeling
- Strong analgesia
- Itch and gentle nodding
Neutral
- Pinpoint pupils (miosis)
- Slowed breathing
- Reduced bowel motility (constipation)
- Decreased libido
Negative
- Respiratory depression and overdose (the actual killer)
- Rapid tolerance and physical dependence
- Severe withdrawal (cramps, sweats, RLS, insomnia, depression)
- Vein damage and abscess if injected without sterile technique
- Long-term cognitive blunting with chronic use
Interactions.
Heads up
Many drug combinations are unsafe even at low doses. When in doubt, take less or abstain. Always cross-check with the interaction checker tool.
Dangerous
Combination may cause serious harm. Avoid.
- benzodiazepines
- alcohol
- gabapentinoids
- ghb
- gbl
- barbiturates
Unsafe
Substantial risk. Combination not recommended.
- ketamine
- dxm
- methamphetamine
- cocaine
Caution
Mild interaction. Use with reduced doses.
- cannabis
- mdma
- ssris
Testing.
- ReagentMarquisExpected reactionPurple (heroin), but reagent does not measure purity or detect fentanyl-class analogues
- ReagentMeckeExpected reactionBlue-green to dark green
- ReagentMandelinExpected reactionBrown to black
- ReagentFentanyl-stripExpected reactionSTRONGLY RECOMMENDED before every batch. Strips test for fentanyl-class analogues and are the single biggest harm-reduction tool for opioids today.
| Reagent | Expected reaction |
|---|---|
| Marquis | Purple (heroin), but reagent does not measure purity or detect fentanyl-class analogues |
| Mecke | Blue-green to dark green |
| Mandelin | Brown to black |
| Fentanyl-strip | STRONGLY RECOMMENDED before every batch. Strips test for fentanyl-class analogues and are the single biggest harm-reduction tool for opioids today. |
Cross-check with a secondary reagent. Tests tell you what something isn't, not always what it is.
Legal status.
- DEGermanyIllegal
- ATAustriaIllegal
- CHSwitzerlandIllegal
- NLNetherlandsSchedule I
- BEBelgiumIllegal
- LULuxembourgIllegal
- FRFranceIllegal
- ESSpainIllegal
- PTPortugalDecriminalised
- ITItalySchedule I
- PLPolandIllegal
- CZCzechiaIllegal
- SESwedenIllegal
- DKDenmarkIllegal
- NONorwayIllegal
- FIFinlandIllegal
- IEIrelandClass A
- UKUnited KingdomClass A
- USUnited StatesSchedule I
- CACanadaSchedule I
- AUAustraliaSchedule 9
- TRTurkeyIllegal
- NZNew ZealandClass A
- BRBrazilIllegal
- MXMexicoIllegal
| Country | Status |
|---|---|
| DEGermany | Illegal |
| ATAustria | Illegal |
| CHSwitzerland | Illegal |
| NLNetherlands | Schedule I |
| BEBelgium | Illegal |
| LULuxembourg | Illegal |
| FRFrance | Illegal |
| ESSpain | Illegal |
| PTPortugal | Decriminalised |
| ITItaly | Schedule I |
| PLPoland | Illegal |
| CZCzechia | Illegal |
| SESweden | Illegal |
| DKDenmark | Illegal |
| NONorway | Illegal |
| FIFinland | Illegal |
| IEIreland | Class A |
| UKUnited Kingdom | Class A |
| USUnited States | Schedule I |
| CACanada | Schedule I |
| AUAustralia | Schedule 9 |
| TRTurkey | Illegal |
| NZNew Zealand | Class A |
| BRBrazil | Illegal |
| MXMexico | Illegal |
Information, not legal advice. Status varies by region and changes over time.
FAQ.
How long does Heroin last?
A typical oral Heroin experience peaks around 60–120 minutes and then tails off, with after-effects that can run several hours. The exact window depends on dose, body weight and what else you've eaten or taken.
Can you overdose on Heroin?
Yes. Higher doses sharply raise the risk of acute harm (cardiovascular strain, hyperthermia, serotonin issues for serotonergic drugs, respiratory depression for downers). Stick to the lowest dose that gives you the effect you're after, never re-dose blindly, and use our [dose calculator](/tools/dosage-calculator) before you weigh anything out.
Is Heroin addictive?
Heroin can produce psychological dependence with frequent use, especially in unstable settings or when used to self-medicate. Physical dependence varies by substance class; the safest pattern is occasional use with long breaks (often 4–6 weeks minimum) and an honest read on why you're reaching for it.
What does Heroin feel like?
Common subjective effects include the ones listed in the Effects section above. Set and setting massively shape the experience: a calm space, trusted people, food eaten, sleep the night before, and your own current mood all matter more than most people expect.
Can you mix Heroin with alcohol?
Mixing with alcohol is rarely a good idea. it dulls your judgement of how much you've taken, dehydrates you, and stacks cardiovascular load. If alcohol is on the table, drink less than normal, alternate with water, and run the combination through our [interaction checker](/tools/interaction-checker) first.
How do I test Heroin at home?
A basic reagent kit (Marquis + Mandelin + Mecke for most stimulants/entactogens; Ehrlich for tryptamines) gives you a fast presence check. It does NOT measure dose or purity, but it does rule out the most dangerous misrepresentations. See the [reagent guide](/tools/reagent-guide) for expected colors per reagent.
How much Heroin is too much?
There's no single number that applies to everyone. As a rule, anything above the 'strong' dose range (30-50 mg for the primary route) carries sharply higher risk of acute harm. Start low, don't redose blindly, and remember that purity varies batch to batch.
How long until Heroin kicks in?
Onset is typically 3-10 minutes via the primary route. Don't redose because you 'don't feel anything yet.' Many people have overdone it by stacking doses during the come-up window.
Can you build tolerance to Heroin?
Yes. Regular use builds tolerance, meaning you need more for the same effect. This escalation increases both health risk and dependence potential. The best counter is long breaks between sessions (2-4 weeks minimum for most substances, 3 months for MDMA-class drugs).
Is Heroin tested for in standard drug screens?
Yes. Heroin is typically detected under the opiates category in standard SAMHSA-5 panels. Urine detection window is roughly 2-4 days. See our [detection guide](/news/how-long-does-heroin-stay-in-your-system) for full details.