WARNINGDANGER OF DEATH
High doses alone or ordinary doses in combination with other depressants can fatally stop breathing.
Acrylfentanyl
Acrylfentanyl is a synthetic opioid of the anilinopiperidine class and a structural analog of fentanyl that has been sold online as a designer drug.1 It is reported to be slightly more potent than fentanyl itself, with a longer duration of action. Very little reliable information exists regarding its safe use or dosage parameters. It is considered potentially neurotoxic and carcinogenic,citation needed and overdose carries significant risk of fatal respiratory depression.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Extreme caution is advised when handling or consuming this substance.
Duration
Subjective Effects
Legacy content. A statistically backed ontology from Mindstate Design Labs is coming soon.
The experience is that of a classic potent opioid: a warm, euphoric mood lift accompanied by pronounced relaxation, pain relief, and sedation, with little to no sensory alteration. As a fentanyl analog, its effect profile closely mirrors that of fentanyl itself, including a serious and potentially life-threatening degree of respiratory depression at higher doses.
Physical
The body feels heavy, relaxed, and free of pain. Typical opioid side effects accompany this, including itchiness, dry mouth, constipation, constricted pupils, and nausea, along with dose-dependent respiratory depression.
Sedation
Uncomfortable
Cognitive
The headspace is dominated by euphoria and an elevated, contented mood rather than any notable alteration of thought or perception.
Pharmacology
Pharmacodynamics
Acrylfentanyl is a highly potent opioid analgesic that acts at the μ-opioid receptor.citation needed In animal studies, it displaces naloxone with an IC50 of 1.4 nM, making it slightly more potent than fentanyl itself (1.6 nM). Because acrylamide derivatives are often used in drug discovery to produce covalent inhibitors that bind irreversibly to their targets, acrylfentanyl has been claimed to be naloxone-resistant. However, acute intoxication studies in mice have demonstrated that naloxone can displace acrylfentanyl from the opioid receptor.
Pharmacokinetics
The metabolism of Acrylfentanyl has been documented. The observed biotransformations were N-dealkylation, monohydroxylation followed by glucuronidation, dihydroxylation followed by glucuronidation, dihydrodiol formation and dihydroxylation with methylation followed by amidehydrolysis.citation needed
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.
Opioids (full cross-tolerance expected with all μ-opioid receptor agonists)
Harm Potential
Addiction & Dependence
Psychological
HighClassified as habit-forming. As a potent fentanyl analog, it carries the high addiction potential characteristic of opioids.2
Toxicity
Acrylfentanyl has been linked to 20 deaths in Sweden and two deaths in Denmark in the summer of 2016. As a class, fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the resurgence in use beginning in Estonia in the early 2000s.
Has been described as potentially neurotoxic.
Has been described as potentially carcinogenic.
History & Culture
Acrylfentanyl emerged as a novel psychoactive substance in the designer drug market during the mid-2010s as part of a broader wave of illicit fentanyl analogs.citation needed The compound is a structural analog of fentanyl, featuring an acryloyl group modification, and was primarily distributed…
Legality
International
Acryloylfentanyl is included in Schedule I of the 1961 Single Convention on Narcotic Drugs. UNODC records its international scheduling in 2018.
By Country
United StatesIllegal
CanadaIllegal (analog/blanket ban)
GermanyIllegal
NetherlandsIllegal
SingaporeIllegal
SwedenIllegal
United KingdomIllegal
MexicoRestrictedReferences
Source Pages
Citations
- Gasperini S, Bilel S, Cocchi V, Marti M, Lenzi M, & Hrelia P. (2022). The Genotoxicity of Acrylfentanyl, Ocfentanyl and Furanylfentanyl Raises the Concern of Long-Term Consequences. https://doi.org/10.3390/ijms2322144061
- Wilde M, Pichini S, Pacifici R, Tagliabracci A, Busardò FP, Auwärter V, & Solimini R. (2019). Metabolic Pathways and Potencies of New Fentanyl Analogs. https://doi.org/10.3389/fphar.2019.002381
- 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
- Betäubungsmittelgesetz, Anlage I. gesetze-im-internet.de (n.d.). https://www.gesetze-im-internet.de/btmg_1981/BJNR106810981.html1
- Ley General de Salud. diputados.gob.mx (n.d.). https://www.diputados.gob.mx/LeyesBiblio/pdf/LGS.pdf1
- Opiumwet. wetten.overheid.nl (n.d.). https://wetten.overheid.nl/BWBR0001941/1
- First Schedule, Misuse of Drugs Act 1973. sso.agc.gov.sg (n.d.). https://sso.agc.gov.sg/Act/MDA1973?ProvIds=Sc1-1
- First Schedule, Misuse of Drugs Act 1973. sso.agc.gov.sg (n.d.). https://sso.agc.gov.sg/Act/MDA1973?ProvIds=pr5-1
- Förordning (1992:1554) om kontroll av narkotika. riksdagen.se (n.d.). https://www.riksdagen.se/sv/dokument-och-lagar/dokument/svensk-forfattningssamling/forordning-19921554-om-kontroll-av-narkotika_sfs-1992-1554/1
- Misuse of Drugs Act 1971 and Misuse of Drugs Regulations 2001. gov.uk (n.d.). https://www.gov.uk/government/publications/controlled-drugs-list--2/list-of-most-commonly-encountered-drugs-currently-controlled-under-the-misuse-of-drugs-legislation1
Further Reading
Guerrieri et al. 2017 - Acrylfentanyl: Another new psychoactive drug with fatal consequences- Helander et al. 2018 - Intoxications involving acrylfentanyl in Sweden
Reddit r/researchchemicals - PSA: Acrylfentanyl user reports on naloxone resistance (2017)
UNODC: Early Warning Advisory - Analytical Report on Acrylfentanyl (2017)- Watanabe et al. 2017 - Acrylfentanyl: metabolism, potency and forensic cases
Article Status
Step 1 · Automated synthesisAn autonomous workflow built by Josie Kins compiled this article's foundation from information published across the web.
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A first pass manual review and edit of article prose and copy has been performed by subject-matter expert Lyrea. This does not guarantee factual accuracy. An additional human review for each of this article's citations is yet to be performed.
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Recent changes8 human edits · latest
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16 August 2026
Lyrea · Edited in Pharmacology › Pharmacokinetics
Lyrea · Reworded 2 words in Pharmacology › Pharmacokinetics
Lyrea · Edited in Pharmacology › Pharmacokinetics
Lyrea · Reworded 6 words in Pharmacology › Pharmacokinetics
Lyrea · Reworded 9 words in Pharmacology › Pharmacokinetics
Lyrea · Reworded 7 words in Pharmacology › Pharmacokinetics
Lyrea · Added a source: In Vitro and In Vivo Metabolite Identification Studies for the New Synthetic Opioids Acetylfentanyl, Acrylfentanyl, Furanylfentanyl, and 4-Fluoro-Isobutyrylfentanyl
24 January 2026
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
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