white → brown2 → purple2
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WARNINGDANGER OF DEATH
High doses alone or ordinary doses in combination with other depressants can fatally stop breathing.
Heroin
Diacetylmorphine
Diamorphine, H, Smack, Junk, Brown
Heroin (diacetylmorphinecitation needed) is a semi-synthetic opioid of the morphinan class derived from morphine, a natural product of the opium poppy. First synthesized by a British chemist in 1874 and later commercialized by Bayer in 1898, it is among the most notorious substances of abuse worldwide. Heroin is highly addictive and exists in forms ranging from white or brown powder to black tar1, with street purity varying dramatically from as low as 5% to as high as 95%.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Threshold~5 mg
Light5-20 mg
Moderate20-35 mg
Strong35-50 mg
Heavy50+ mg
Duration
Onset10-60 seconds
Come Up10-60 seconds
Peak1-90 minutes
Offset1-3 hours
After Effects1.5-3 hours
Total3-7 hours
Subjective Effects
Legacy content. A statistically backed ontology from Mindstate Design Labs is coming soon.
Effects vary widely by individual, dose, and context.
Physical
The physical effects of heroin can be broken down into several components which progressively intensify proportional to dosage.
Cognitive
The cognitive effects of heroin can be broken down into several components which progressively intensify proportional to dosage.
Visual
Pharmacology
Pharmacodynamics
Heroin (diamorphine) itself exhibits relatively low affinity for the μ-opioid receptor and functions primarily as a prodrug.citation needed Its pharmacological effects are mediated through its active metabolites morphine and 6-monoacetylmorphine (6-MAM), both of which are μ-opioid receptor agonists. Morphine additionally binds to δ- and κ-opioid receptors.2 These opioid metabolites also decrease the inhibitory activity of GABAergic interneurons, resulting in increased dopamine release.citation needed There is evidence that 6-MAM may bind to a distinct μ-opioid receptor subtype (mu-3), though the contribution of this receptor to heroin's overall pharmacology remains unknown.
Pharmacokinetics
Heroin undergoes rapid deacetylation by esterase enzymes, with a parent compound half-life of approximately two to three minutes.citation needed When taken orally, it is subject to extensive first-pass metabolism, yielding oral bioavailability below 35%. Deacetylation produces the active metabolites 6-monoacetylmorphine (6-MAM) and morphine, along with the inactive 3-monoacetylmorphine. When injected, the acetyl groups confer lipophilicity that allows rapid crossing of the blood-brain barrier before central deacetylation occurs. The majority of the drug is excreted renally as glucuronides, with approximately 7 to 10% eliminated via the biliary system.3
Dangerous
Highest riskThese combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.
Unsafe
AvoidThere is considerable risk of physical harm when taking these combinations, they should be avoided where possible.
Caution
Use cautionThese combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.
Tolerance
Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.
Full Tolerance
With sustained repeated heroin use, many effects become less responsive. Tolerance does not develop at the same pace for every effect; constipation-related tolerance is especially slow compared with other effects. As a result, users may need progressively higher doses to obtain effects that previously occurred at lower doses.
Baseline Reset
1-2 weeks
Half Tolerance
3-7 days
Cross Tolerance
Opioids (all other opioid receptor agonists will have reduced effect after heroin consumption)
Harm Potential
Addiction & Dependence
Psychological
Extremely HighHeroin is considered extremely addictive with a high potential for abuse.citation needed The combination of powerful euphoric effects and rapid tolerance development leads many users to compulsive redosing and difficulty controlling their use. Psychological dependence can develop quickly, often accompanied by cravings and loss of interest in other activities.
Physical
HighProfound physical dependence develops with repeated use. Withdrawal symptoms may begin within 2-6 hours of the last dose and include sweating, anxiety, severe muscle and bone aches, nausea, vomiting, diarrhea, insomnia, and involuntary muscle spasms.citation needed While extremely unpleasant, opioid withdrawal is generally not life-threatening.4 Tolerance decreases significantly after periods of abstinence, making relapse particularly dangerous.citation needed
Toxicity
Respiratory
Respiratory depression is the primary mechanism of overdose death; heavy doses suppress breathing proportionally to the amount consumed, potentially reducing breathing rate to 2-4 breaths per minute.
Central Nervous System
Repeated use alters brain structure and physiology, with studies showing some deterioration of white matter in chronic users; these changes may affect decision-making, behavior regulation, and stress responses.citation needed
Auditory
Heroin is known to be ototoxic, causing hearing loss, tinnitus, and balance issues; effects may persist long after use.citation needed
Gastrointestinal
Constipation is a common and persistent effect with regular use, representing one of the few direct long-term complications of unadulterated heroin.
Urinary
Urinary retention and difficulty urinating can occur with chronic and repeated use.
Cardiovascular
Decreased heart rate and hypotension occur during intoxication; heroin use has been associated with myocardial infarction.5
Renal
Decreased kidney function (nephropathy) has been reported in intravenous users.citation needed
Pulmonary
Heroin inhalation has rarely caused toxic leukoencephalopathycitation needed and has been documented to cause severe acute asthma attacks or exacerbation of underlying asthma, potentially resulting in death.
History & Culture
Discovery and Synthesis
Diamorphine was first synthesized in 1874 by C.R. Alder Wright, an English chemist working at St. Mary's Hospital Medical School in London.citation needed Wright had been experimenting with combining morphine with various acids, achieving the synthesis by boiling anhydrous morphine alkaloid with…
Legality
International
1961 Convention: Schedule I.
1971 Convention: not internationally scheduled.
1988 Convention: not internationally scheduled.
By Country
Illegal19
AustraliaSchedule I (Narcotic Drugs Act)Listed in Schedule I of the Narcotic Drugs Act of 1967. Personal quantities under 1 gram have been decriminalized in the Australian Capital Territory as of 28 October 2023.7
ColombiaIllegalDecreto 1019 de 199016
Heroin (diacetylmorphine) appears in Colombia's official controlled-substances list. It is regulated as an estupefaciente under the national narcotics-control framework.
IndiaIllegalNarcotic Drugs and Psychotropic Substances Act, 198525
The Narcotic Drugs and Psychotropic Substances Act treats diacetylmorphine (heroin) as a narcotic drug. The Act prohibits unauthorised production, possession, sale, purchase, transport, use and related dealings.
JapanIllegalNarcotics and Psychotropics Control Act28
Diacetylmorphine, also called heroin, is listed in Schedule I of Japan's Narcotics and Psychotropics Control Act. The Act controls the import, export, manufacture and transfer of narcotics.
LatviaIllegalRegulations No. 84729
Classified as a Schedule I controlled substance under Latvian drug legislation. Possession, production, and distribution are prohibited.
MexicoIllegalLey General de Salud30
Diacetylmorphine or heroin, including its salts and preparations, is expressly covered by Article 237 of the General Health Law. The provision prohibits the acts described in Article 235 for this substance in Mexico.
NetherlandsIllegalOpium Act31
Heroin is listed in List I of the Opium Act. List I substances are hard drugs and the Act prohibits their unauthorised possession, production, sale, import and export.
New ZealandIllegalMisuse of Drugs Act 197532
Controlled as a Class A substance under the Misuse of Drugs Act, the most restrictive classification carrying the most severe penalties.
NorwayIllegalNarkotikaforskriften33
Illegal to buy or possess without a special license. The government has established needle exchange facilities where addicts can obtain clean injection equipment, though the substance itself remains prohibited.
PolandIllegalAct on Counteracting Drug Addiction34
Illegal to produce, sell, and possess under the 'wykaz środków odurzających i substancji psychotropowych' (list of narcotic drugs and psychotropic substances).
RussiaIllegalGovernment Resolution No. 68138
Classified as a Schedule I controlled substance under Russian narcotic drug legislation. Possession, production, and distribution are prohibited.
UkraineIllegalCabinet of Ministers Resolution No. 770 of 6 May 200047
Heroin (diacetylmorphine) is included in Ukraine's official list of narcotic drugs, psychotropic substances and precursors. Listed narcotics are subject to state control and unauthorised handling is criminally regulated.
Prescription5
CanadaPrescription onlyControlled Drugs and Substances Act12
Controlled under the Controlled Drugs and Substances Act.13 Since September 2016, Health Canada has permitted prescription of pharmaceutical diacetylmorphine to severe addicts as a treatment regimen.14 A 2011 Supreme Court decision established a constitutional right under Section 7 of the Charter of Rights and Freedoms to access supervised injection sites.15
GermanyPrescription onlyHeroin (diamorphine) is listed in Anlage III to Germany's Betäubungsmittelgesetz only in preparations authorised for substitution treatment. Anlage III narcotics may be prescribed by physicians, dentists or veterinarians only where administration is medically justified; diamorphine is supplied only by the pharmaceutical entrepreneur to recognised facilities on presentation of the prescription. Unauthorised cultivation, manufacture, trade, import, export, supply, acquisition and possession of narcotics are criminal offences.
SpainPrescription onlyInstrumento de Ratificación del Convenio Único de 1961 sobre Estupefacientes43
Heroin (diacetylmorphine) is listed in Lista IV of Spain’s ratified Single Convention on Narcotic Drugs; Lista IV substances are also included in Lista I and subject to its controls. The Convention has applied to Spain since 31 March 1966 and permits possession only with legal authorization; manufacture, trade, and distribution are subject to licensing, and supply to individuals requires a medical prescription.
United KingdomPrescription onlyControlled under the Misuse of Drugs Act.48 Illegal to buy, sell, or possess without a license. However, under the name diamorphine, it remains a legal prescription medication indicated for severe pain associated with surgical procedures, myocardial infarction, pain in terminally ill patients, and relief of dyspnoea in acute pulmonary edema.3
Legal / decriminalized2
PortugalDecriminalizedPersonal use decriminalized by Law 30/2000, effective July 2001.37 Possession of less than 1g is not a criminal offense, though the substance may be seized and the individual referred to a dissuasion commission for potential treatment. Sale or possession above the personal threshold remains a criminal offense punishable by imprisonment.
References
Source Pages
Drug Users Bible by Dominic Milton Trott
DrugBank- DrugBank: Diamorphine Category
- DrugBank: Diamorphine Salt
- DrugBank: Oral Diacetylmorphine Study
- DrugBank: Swiss Medical Use
Erowid- Erowid: Heroin Basics
- Erowid: Heroin Dosage
Isomer Design (TiHKAL/PiHKAL)
PsychonautWiki
TripSit Factsheets- TripSit Wiki
- TripSit: Combo Chart
Wikipedia
Citations
- Heroin. National Institute on Drug Abuse (n.d.). https://nida.nih.gov/research-topics/heroin1
- Milella MS, D'Ottavio G, De Pirro S, Barra M, Caprioli D, & Badiani A. (2023-04-08). Heroin and its metabolites: relevance to heroin use disorder. Translational Psychiatry, 13, 120. https://doi.org/10.1038/s41398-023-02406-51
- Diamorphine Hydrochloride 10mg for Injection. electronic medicines compendium (emc) (6 May 2020). https://www.medicines.org.uk/emc/product/1466/smpc12
- Fred K. Berger, MD. (n.d.). Opiate and opioid withdrawal: MedlinePlus Medical Encyclopedia. medlineplus.gov. https://medlineplus.gov/ency/article/000949.htm1
- Ritu Karoli, J. Fatima, Pushker Singh, & Khursheed I. Kazmi. (July 2012). Acute myocardial involvement after heroin inhalation. Journal of Pharmacology & Pharmacotherapeutics, 3(3), 282–4. https://doi.org/10.4103/0976-500x.994481
- When Heroin Hit Jazz. City Journal (n.d.). https://www.city-journal.org/article/when-heroin-hit-jazz1
- Decriminalisation of low-level drug possession in the ACT. Hugo Law Group (n.d.). https://hugolawgroup.com.au/insights/decriminalisation-of-low-level-drug-possession-in-the-act/1
- Suchtmittelgesetz. ris.bka.gv.at (n.d.). https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=100110401
- Narcotic Substances Act in Austria: Overview of Rules and Penalties. MPW Rechtsanwaelte (n.d.). https://mpw-rechtsanwaelte.com/en/narcotic-substances-act-austria/1
- Portaria SVS/MS 344/1998. bvsms.saude.gov.br (n.d.). https://bvsms.saude.gov.br/bvs/saudelegis/svs/1998/prt0344_12_05_1998_rep.html1
Further Reading
Article Status
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Recent changes8 human edits · latest
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15 August 2026
Lyrea · Updated the article
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Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
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