white → purple2 → purple2
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WARNINGDANGER OF DEATH
High doses alone or ordinary doses in combination with other depressants can fatally stop breathing.
Oxymorphone
(4R,4aS,7aR,12bS)-4a,9-dihydroxy-3-methyl-2,4,5,6,7a,13-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinoline-7-one
Opana, Numorphan, Stop Signs
Oxymorphone is a semi-synthetic opioid analgesic of the morphinan class, structurally related to morphine and heroin.citation needed First developed in Germany in 1914 and introduced to the American market in 1959, it was designed to produce fewer side effects than its predecessors. Oxymorphone is approximately seven times more potent than morphine and is used in the management of moderate to severe pain. Notably, it is almost entirely devoid of antitussive properties.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Threshold~2.5 mg
Light2.5-10 mg
Moderate10-20 mg
Strong20-30 mg
Heavy30+ mg
Bioavailability
10%
Duration
Onset20-45 minutes
After Effects1-12 hours
Total4-6 hours
Half-life
1.3 hours (±0.7)
Subjective Effects
Legacy content. A statistically backed ontology from Mindstate Design Labs is coming soon.
The experience is dominated by classic opioid effects: potent pain relief, sedation, and a warm sense of physical and emotional well-being. As a full mu-opioid agonist considerably more potent than morphine, oxymorphone produces a heavy, relaxed state with pronounced euphoria and mood lift, accompanied by little in the way of sensory alteration. Central nervous system depression scales with dose, progressing from drowsiness toward stupor, with respiratory depression as the principal danger at high doses.
Physical
The body feels heavy, relaxed, and free of pain. Side effects typical of opioids are common, including itchiness, constipation, dry mouth, nausea, dizziness, sweating, and constricted pupils; respiratory depression becomes dangerous at higher doses.
Comfortable
Sedation
Uncomfortable
Cognitive
The headspace is characterized by euphoria, an elevated mood, and a pervasive sense of well-being and contentment, set against a background of increasing sedation and drowsiness.
Emotional
Pharmacology
Pharmacodynamics
Oxymorphone exerts its primary effects through agonism of the μ-opioid receptor.1 It also interacts with the δ-opioid receptor and, to a much lesser extent, the κ-opioid receptor. The nature of its δ-opioid interaction is not fully agreed upon: it has been characterized as antagonism, but has also been described as an activating interaction that may augment its μ-opioid effects. Through μ-opioid receptors on GABAergic interneurons, oxymorphone disinhibits descending pain modulation pathways. It is approximately 10 times more potent than morphine, with 1 mg of oxymorphone hydrochloride considered equivalent to approximately 9.85 mg of morphine sulfate.citation needed
Pharmacokinetics
Oxymorphone undergoes extensive hepatic metabolism.1 Oral bioavailability is notably low at approximately 10%, attributable to substantial first-pass metabolism,citation needed though co-administration with a large fatty meal can increase it to approximately 40%. The primary metabolic pathway involves conjugation, with the oxymorphone conjugate accounting for the majority of urinary metabolites.2 Additional metabolism occurs via 6-keto reduction, yielding 6β-carbinol and 6α-carbinol derivatives that are subsequently conjugated.citation needed The elimination half-life is approximately 1.3 hours.2
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
Sustained repeated oxymorphone use can produce tolerance to many effects, including therapeutic effects. Tolerance develops at different rates across effects, with constipation-related tolerance emerging especially slowly compared with other opioid effects.
Cross Tolerance
All other opioids
Harm Potential
Addiction & Dependence
Psychological
Extremely HighOxymorphone is considered extremely addictive with high abuse potential.citation needed Compulsive redosing is commonly reported, and the drug has been classified as a high-risk opioid due to misuse and abuse concerns.
Physical
HighChronic use reliably produces physical dependence with withdrawal symptoms occurring upon cessation.citation needed Neonatal withdrawal syndrome can occur in infants born to mothers who used oxymorphone during pregnancy.
Toxicity
Respiratory
Heavy doses can cause respiratory depression leading to dangerous or fatal levels of oxygen deprivation; this is the primary mechanism of opioid overdose death and risk increases substantially when combined with other depressants.citation needed
Gastrointestinal
Constipation occurs commonly with use and tolerance to this effect develops particularly slowly compared to other opioid effects.citation needed
Cardiovascular
Severe overdose may cause bradycardia, hypotension, circulatory collapse, and cardiac arrest.3
Hematological
Intravenous injection of the reformulated oral tablet has been associated with a rare TTP-like syndrome (thrombotic microangiopathy); this appears specific to abuse of the crush-resistant formulation and does not occur with intended routes of administration.citation needed
History & Culture
Discovery and Development
Oxymorphone was first developed in Germany in 1914citation needed as part of efforts to create opioid analgesics with improved side effect profiles compared to morphine and heroin. The compound exhibits actions and uses similar to morphine, though notably lacks cough suppressant activity.…
Legality
International
Oxymorphone is internationally scheduled in Schedule I of the 1961 Single Convention on Narcotic Drugs. It is not listed in the schedules to the 1971 Convention on Psychotropic Substances or in the tables to the 1988 Convention against Illicit Traffic.
By Country
Illegal1
Controlled / restricted1
GermanyRestrictedOxymorphon is listed in Anlage II of the Betäubungsmittelgesetz as a marketable but non-prescribable narcotic. The Act requires authorization from the Federal Institute for Drugs and Medical Devices to acquire, manufacture, trade, import, export, supply, sell, or otherwise place the substance on the market. It may not be prescribed, administered, or supplied for direct consumption.
Prescription17
United StatesPrescription only21 CFR 1308.1233
Oxymorphone is controlled under the Controlled Substances Act.34 Selling it requires a DEA license, and buying or possessing it is unlawful unless covered by a license or prescription. In 2017, the FDA requested that Endo Pharmaceuticals remove the extended-release formulation from the market because of concerns about opioid misuse and abuse linked to the injectable reformulation.5
ArgentinaPrescription onlyLa oximorfona figura como estupefaciente de la Lista I en la Ley N.º 17.818, vigente desde 1968. Las preparaciones medicinales que contienen sustancias de la Lista I sólo pueden ser prescritas por profesionales médicos matriculados mediante receta en formularios oficializados; la importación, fabricación, circulación y expendio quedan sujetos a la ley y a control sanitario.
BrazilPrescription onlyPortaria SVS/MS nº 344/1998, Lista A19
Oxymorphone is included in Brazil's List A1 of narcotic substances. Its dispensing and handling are subject to the special-control rules.
CanadaPrescription onlyControlled Drugs and Substances Act, Schedule I10
Oxymorphone is a Schedule I narcotic under the Controlled Drugs and Substances Act. Its possession and distribution are permitted only as authorized under the federal regulatory framework.
IndonesiaPrescription onlyLaw No. 35 of 2009 on Narcotics, Schedule14
Oxymorphone is included in Indonesia's narcotics schedule. The substance is subject to the statutory narcotics restrictions and authorized medical provisions.
IrelandPrescription onlyMisuse of Drugs Regulations 2017, Schedule 215
Oxymorphone is listed as a Schedule 2 controlled drug. Supply and possession are subject to the prescription and authorization rules for that schedule.
ItalyPrescription onlyD.P.R. 309/1990, Tabella I16
Oxymorphone is placed in Italy's Table I of controlled substances. Its medical use and handling are governed by the national narcotics framework.
JapanPrescription onlyNarcotics and Psychotropics Control Act17
Oxymorphone is treated as a narcotic under Japan's narcotics-control law. Authorized medical handling is regulated under that Act.
New ZealandPrescription onlyMisuse of Drugs Act 1975, Schedule 218
Oxymorphone is listed as a Class B controlled drug in New Zealand. The Act restricts it while allowing authorized medical access.
PhilippinesPrescription onlyComprehensive Dangerous Drugs Act of 2002, Schedule I19
Oxymorphone is listed in the Philippines' Schedule I of dangerous drugs. Its possession and distribution are controlled by the Comprehensive Dangerous Drugs Act.
SingaporePrescription onlyMisuse of Drugs Act, First Schedule22
Oxymorphone is included in Singapore's First Schedule of controlled drugs. It is subject to the Act's restrictions and authorized-use provisions.
South AfricaPrescription onlyMedicines and Related Substances Act, Schedule 623
Oxymorphone is subject to South Africa's Schedule 6 medicine controls. Supply is restricted to the prescription and recordkeeping requirements applicable to that schedule.
SwedenPrescription onlyLVFS 2011:10, list of narcotic drugs24
Oxymorphone is listed as a narcotic drug in Sweden. The classification subjects it to Sweden's narcotics and prescription controls.
SwitzerlandPrescription onlyBetäubungsmittelverzeichnisverordnung (BetmVV-EDI)25
Listed under Verzeichnis A in the Swiss controlled substances regulations. Medicinal use is permitted with appropriate authorization and licensing.
TurkeyPrescription onlyOxymorphone is a Schedule I narcotic drug under the Turkish text of the 1961 Single Convention annexed to Law No. 812, which was published on 5 January 1967. The Convention requires narcotic drugs to be limited to medical and scientific purposes and requires their supply or distribution to individuals only on a doctor's prescription. Turkey's Law No. 2313 further provides that retail sale of narcotic drugs on prescription may take place only in pharmacies opened under the Pharmacy and Pharmacists Law.
United Arab EmiratesPrescription onlyOxymorphone is a Narcotic Schedule I medicine in the United Arab Emirates. Federal Law by Decree No. 30 of 2021 criminalises possession, production, import, export, transport, purchase, sale and storage of narcotic substances outside supervised and regulated medical or scientific activities; the official controlled-medicines list allows travellers to carry oxymorphone only for the period of stay or up to three months, with a medical prescription or attested medical report.
United KingdomPrescription onlyReferences
Source Pages
Citations
- OPANA (oxymorphone hydrochloride) tablets prescribing information. Endo Pharmaceuticals / DailyMed (n.d.). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=285e60f8-2404-47d0-a171-a4f075d6f41812
- Numorphan (oxymorphone) prescribing information. Endo Pharmaceuticals / RxList (n.d.). https://www.rxlist.com/numorphan-drug.htm12345
- Oxymorphone Hydrochloride Tablets — Full Prescribing Information. DailyMed / U.S. National Library of Medicine (n.d.). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=560e9425-dfcb-4fb4-a759-b1e3f8f40fdb12
- Thrombotic Thrombocytopenic Purpura (TTP)–Like Illness Associated with Intravenous Opana ER Abuse — Tennessee, 2012. Morbidity and Mortality Weekly Report, 62(1), 1–4 (January 11, 2013). https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6201a1.htm1
- U.S. Food and Drug Administration. (8 June 2017). FDA Requests Removal of Opana ER for Risks Related to Abuse. https://www.hiv.gov/blog/fda-requests-removal-opana-er-risks-related-abuse123
- CDC. (11 January 2013). Thrombotic Thrombocytopenic Purpura (TTP)–Like Illness Associated with Intravenous Opana ER Abuse — Tennessee, 2012. MMWR Morbidity and Mortality Weekly Report, 62(1), 1–4. https://pmc.ncbi.nlm.nih.gov/articles/PMC4604918/1
- Ley N.º 17.818 (Estupefacientes). servicios.infoleg.gob.ar (n.d.). https://servicios.infoleg.gob.ar/infolegInternet/anexos/20000-24999/20883/texact.htm1
- Ley N.º 17.818 (Estupefacientes). servicios.infoleg.gob.ar (n.d.). https://servicios.infoleg.gob.ar/infolegInternet/anexos/305000-309999/306114/norma.htm1
- Portaria SVS/MS nº 344/1998, Lista A1. bvsms.saude.gov.br (n.d.). https://bvsms.saude.gov.br/bvs/saudelegis/svs/1998/prt0344_12_05_1998_rep.html1
- Controlled Drugs and Substances Act, Schedule I. laws-lois.justice.gc.ca (n.d.). https://laws-lois.justice.gc.ca/eng/acts/C-38.8/FullText.html1
Further Reading
Article Status
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Recent changes8 human edits · latest
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16 August 2026
Lyrea · Changed a word in Dosage & Duration › Routes 1 › Dose ranges › Light
24 January 2026
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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