Dose 12 mg Acetyl Fentanyl IM'ed Preparation - I mixed 12 mg (0.012 g) Acetyl Fentanyl with 50 units (0.5 mL) of water. I drew up less than 50 units of fluid into the rig through cotton. Next I ejected the rig down to 40 units of fluid for ease of measurement.
Acetylfentanyl
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 6 corroborating sources
- no dose data
- duration data present
- 29 combo interactions documented
- toxicity data (PsychonautWiki)
- classified Research-chemical
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 6 corroborating sources
- no dose data
- duration data present
- 29 combo interactions documented
- toxicity data (PsychonautWiki)
- classified Research-chemical
Aliases: A-f, Desmethyl fentanyl, acetyl-fentanyl
Summary
Acetylfentanyl is a synthetic opioid substance of the anilidopiperidine chemical class that produces analgesic, anxiety suppressing, and euphoric effects when administered. It is a structural analog of fentanyl. The DEA places its potency at roughly 15.7 times morphine β about one third of fentanyl. Much higher multiples circulate in older secondary sources (up to eighty times morphine); they are not supported by the measured data and are the figures this page previously repeated.
Dose Information
Dose basis. No verified human dose exists for acetylfentanyl. A previous version of this page carried a numeric dose ladder that was wrong by roughly one to two orders of magnitude in the dangerous direction. It was removed on 7 August 2026 rather than replaced, because the defensible corrections span a 15-fold range and publishing a precise number we cannot source is the error that caused the problem. What is documented: the DEA reports it as roughly one third the potency of fentanyl and 15.7 times that of morphine, with an effective-to-lethal dose range NARROWER than either. For scale, our own fentanyl record puts a common sublingual or insufflated dose at 25-50 micrograms. Assume this compound is active in micrograms, that a milligram scale cannot weigh it, and that naloxone may need repeat doses.
Onset, Duration & After-effects
| ROA | Onset | Total |
|---|---|---|
| Sublingual | 20-40 min | 1-4 hrs |
| Insufflated | 7-10 min | 3-4 hrs |
Effect Profile
4 reportsScores (0–10) curated from multiple sources:
- Effect keyword matching from PsychonautWiki catalog
- Weighted by importance: core (×3), major (×2), minor (×1)
Opioid
8.4
Intense
8/10
Strong euphoria and pain relief with moderate sedation, mild itching/nausea
Euphoria / Warmth
×3
10
physical euphoria
cognitive euphoria
euphoria
mood lift
Analgesia
×2
8
pain relief
analgesia
Sedation / Relaxation
×1
7
sedation
drowsiness
dream potentiation
Itching / Nausea
×1
4
constipation
dry mouth
Based on reports from:
Tolerance
Build-up
develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
Reset
Falls quickly once you stop, at a rate you can't judge. After any break, treat your tolerance as gone.
No tolerance chart. Our decay curves for opioids were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.
Opioid tolerance drops fast when you stop, and even a few days off can be enough, so a dose that used to be normal can now stop your breathing. Overdose deaths rise sharply after prison, detox or leaving treatment, and tolerance also falls during a hospital stay. After any break, start with a much smaller amount, try a test dose first, don't use alone, and keep naloxone within reach. Alcohol, benzodiazepines, gabapentinoids and other sedatives make an opioid overdose much more likely.
Sources: FRANK: heroin Β· National Harm Reduction Coalition Β· WHO: opioid overdose Β· Merrall et al. 2010 Β· Binswanger et al. 2007 Β· Strang et al. 2003 Β· FDA 2019: gabapentinoids and breathing
Effects
Effect glossary — · full glossary
Positive
Negative
Positive
Negative
- Changes in focus
Negative
Combinations
Cross-Check Acetylfentanyl with another substanceCommunity Trip Reports
Anecdotal first-person accounts from Reddit, Erowid, Bluelight, and Dose.wiki. Click a source to expand. Reports are harm-reduction context, not medical guidance. Tags summarise each author's own verdict — how reports are classified.
Erowid 4 reports 2 neutral 2 cautionary visit
AcetylFentanyl - word was this was a research chemical with properties similar to Heroin or Morphine. In fact, it is touted as stronger than both. I bought a full gram (enough to put down ten 200 lb people for good, so be careful with the dosage). Stuff is extremely cheap.
Hey. I'm just a 20 year old college kid who's dabbled in drugs quite a bit. I'm up in Canada and fentanyl is making its rounds around here. I managed to get some candies dipped in 5mg Acetyl Fentanyl. Perhaps they were bunk or not really 5mg but I kept redosing and couldn't get any euphoria from these.
I started taking acetyl fentanyl blotters that I bought off the dark net for two months solid. ThatΒs one of the hardest withdrawals youΒll ever know in life. ItΒs worse than dilaudid, worse than oxy, worse than hydrocodone, itΒs 50-100 times stronger than heroin but still 15 times less than fentanyl.
Acetylfentanyl's nerd page
Pharmacology, chemical data, effect profiles, and more
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