Desmethylflunitrazepam
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 2 corroborating sources
- 2 ROAs with full dose ladders
- duration data present
- 27 combo interactions documented
- classified Research-chemical
- 2 corroborating sources
- 2 ROAs with full dose ladders
- duration data present
- 27 combo interactions documented
- classified Research-chemical
Aliases: Fonazepam, Ro05-4435, Norflunitrazepam, N-desmethylflunitrazepam
Summary
Extremely potent benzodiazepine requiring accurate milligram-scale measurement. Produces profound anterograde amnesia and severe motor impairment; users commonly experience complete blackouts at doses above 2 mg. Long elimination half-life leads to significant next-day impairment and cumulative effects with repeated dosing.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 0.5-1mg | 1-2mg | 2-4mg | 4mg+ |
| Sublingual | 0.5-1mg | 1-2mg | 2-4mg | 4mg+ |
Onset, Duration & After-effects
| ROA | Onset | Peak | Offset | Total |
|---|---|---|---|---|
| Oral | 20-60 min | 2-4 hrs | 6-10 hrs | 5-10 hrs |
| Sublingual | 15-45 min | 2-4 hrs | 6-10 hrs | 5-10 hrs |
| Insufflated | 10-30 min | 2-4 hrs | 6-10 hrs | 5-10 hrs |
Effect Profile
Scores (0–10) curated from multiple sources:
- Effect keyword matching from PsychonautWiki catalog
- Weighted by importance: core (×3), major (×2), minor (×1)
Strong anxiolysis and euphoria with strong cognitive impairment, mild sedation
Tolerance
No tolerance chart. Our decay curves for these drugs were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.
How fast tolerance to these drugs fades after a break has not been measured well enough to draw, so don't count on a dose you used to take still being safe: after time off, start with a much smaller amount and don't use alone. Mixing sedatives with each other, with alcohol or with opioids sharply raises the risk of a fatal overdose. If you've been using regularly, don't stop suddenly: withdrawal from benzodiazepines, alcohol or GHB/GBL can cause seizures or delirium, so get medical help to cut down gradually.
Sources: FRANK: benzodiazepines · Alcohol and Drug Foundation: GHB · FDA 2020: benzodiazepine boxed warning · FDA 2019: gabapentinoids and breathing · NHS: alcohol use disorder
Cross-Tolerances
Effects
Effect glossary — · full glossary
Combinations
Cross-Check Desmethylflunitrazepam with another substanceHelpful Links
Add to PsychonautWiki Journal
The PsychonautWiki Journal logging app doesn't include every substance. To track Desmethylflunitrazepam there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:
Desmethylflunitrazepam Source: SubstanceSearch (substancesearch.com) Oral dose (mg): light 0.5-1 · common 1-2 · strong 2-4 · heavy 4+ Sublingual dose (mg): threshold 0.2 · light 0.5-1 · common 1-2 · strong 2-4 · heavy 4+ Oral duration: onset 0.33-1h · peak 2-4h · offset 6-10h · total 5-10h · after-effects 12-24h Sublingual duration: onset 15-45m · peak 2-4h · offset 6-10h · total 5-10h · after-effects 12-24h Insufflated duration: onset 10-30m · peak 2-4h · offset 6-10h · total 5-10h · after-effects 12-24h 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 ~ 1.5 mg (Oral).
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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