Lofentanil
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 2 corroborating sources
- 2 ROAs with full dose ladders
- duration data present
- 29 combo interactions documented
- PubChem toxicity data
- classified Research-chemical
- dose data not in PW/TripSit (unverifiable)
- 2 corroborating sources
- 2 ROAs with full dose ladders
- duration data present
- 29 combo interactions documented
- PubChem toxicity data
- classified Research-chemical
- dose data not in PW/TripSit (unverifiable)
Aliases: R-32792, R-34995, 3-methyl-4-carbomethoxyfentanyl
Summary
Due to a sub-microgram active range, ordinary analytical balances cannot measure a non-lethal dose; volumetric dilution under inert atmosphere is essential. Naloxone may require large, repeated boluses because of lofentanil's long receptor residence time. This is one of the most potent opioids known, approximately 6000 times more potent than morphine, and has an extremely long duration of action compared to other fentanyl analogs.
Dose Information
Dose basis. The dose figures on this page are not clinical data. They are aggregated from community reports by a secondary source whose own notes state there is no human pharmacokinetic study behind them, and our internal audit flags this substance's dosing as unverifiable. Treat them as a rough orientation, not a safe range. This is a microgram-active opioid: a normal milligram scale cannot weigh a dose of it accurately, and a weighing error here is measured in lethal multiples rather than percentages. Volumetric dosing is the only defensible method, and batch-to-batch potency in the unregulated supply varies enormously. Assume full respiratory depression, keep naloxone to hand, never dose alone, and never combine with benzodiazepines, alcohol or other depressants.
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Intravenous | 0.1-0.3ยตg | 0.3-1ยตg | 1-2ยตg | 2ยตg+ (rapidly lethal) |
| Insufflated | 0.2-0.6ยตg | 0.6-1.5ยตg | 1.5-3ยตg | 3ยตg+ |
Sources· 1 of 2 ladders not identified
Intravenous
Dose ladder — Drugs.WikiInsufflated
Dose ladder — source not identified“The intravenous dose ladder itself carries the annotation: "2 ug+ (rapidly lethal)".” — community dose ladder
Onset, Duration & After-effects
| ROA | Onset | Peak | Offset | Total |
|---|---|---|---|---|
| Intravenous | 1-2 min | 10-30 min | 4-6 hrs | 4.18-6.53 hrs |
| Insufflated | 5-10 min | 10-30 min | 4-6 hrs | 4.25-6.67 hrs |
Effect Profile
Scores (1–10) curated from multiple sources:
- Effect keyword matching from PsychonautWiki catalog
- Weighted by importance: core (×3), major (×2), minor (×1)
Strong euphoria, itching/nausea, and pain relief with low sedation
Tolerance
Tolerance Decay
Acute tolerance: develops within a single session โ the reset numbers above apply after sustained heavy use, not after one binge. Within-session tachyphylaxis usually resets largely overnight.
Based on general opioid patterns and limited analog data: tolerance can rise quickly with continuous exposure and decays over weeks. Estimates are approximate and carry low confidence.
Cross-Tolerances
Effects
Effect glossary — · full glossary
Combinations
Cross-Check Lofentanil with another substanceHelpful Links
Add to PsychonautWiki Journal
The PsychonautWiki Journal logging app doesn't include every substance. To track Lofentanil there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:
Lofentanil Source: SubstanceSearch (substancesearch.com) Intravenous dose (ยตg): threshold 0.1 ยท light 0.1-0.3 ยท common 0.3-1 ยท strong 1-2 ยท heavy 2+ (rapidly lethal) Insufflated dose (ยตg): threshold 0.2 ยท light 0.2-0.6 ยท common 0.6-1.5 ยท strong 1.5-3 ยท heavy 3+ Intravenous duration: onset 1-2m ยท peak 10-30m ยท offset 4-6h ยท total 4.18-6.53h ยท after-effects 2-6h Insufflated duration: onset 5-10m ยท peak 10-30m ยท offset 4-6h ยท total 4.25-6.67h ยท after-effects 2-6h Note: ranges are harm-reduction guidance, not a prescription. Start low, go slow, and test your substances.
Tip: for quicker logging you can also add a Custom Unit in the app, e.g. common dose ~ 0.65 ยตg (Intravenous).
The app keeps custom substances simple, so the full dose ranges live in the description text above. Ranges are harm-reduction guidance, not a prescription.
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