Halazepam
Well-documented
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 2 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 27 combo interactions documented
- PubChem toxicity data
- 2 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 27 combo interactions documented
- PubChem toxicity data
Aliases: Paxipam, Alapryl, Pacinone
Summary
Halazepam is a trifluoromethyl derivative of nordazepam (desmethyldiazepam) with anxiolytic, anticonvulsant, sedative, and muscle relaxant properties. It is metabolized into pharmacologically active desmethyldiazepam with a half-life of 30-100 hours, contributing to prolonged effects and accumulation with repeated use. Halazepam was marketed as having lower toxicity and less tendency to cause paradoxical hostility than diazepam, though it was withdrawn from the US market in 2009 due to poor sales.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 10-20mg | 20-40mg | 40-80mg | 80mg+ |
Benzo Equivalence Calculator
| Substance | Equivalent Dose | Potency |
|---|
⚠ These are approximate equivalences for educational and cross-tapering reference. Individual response, tolerance, and half-life differences mean actual equivalence varies. Always consult a healthcare provider for tapering guidance.
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | Total |
|---|---|---|---|---|---|
| Oral | 30-60 min | 1-2 hrs | 1-3 hrs | 6-12 hrs | 8-14 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 Halazepam with another substancePill Identifiers
Helpful Links
Add to PsychonautWiki Journal
The PsychonautWiki Journal logging app doesn't include every substance. To track Halazepam there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:
Halazepam Source: SubstanceSearch (substancesearch.com) Oral dose (mg): light 10-20 · common 20-40 · strong 40-80 · heavy 80+ Oral duration: onset 0.5-1h · come-up 1-2h · peak 1-3h · offset 6-12h · total 8-14h · after-effects 24-48h 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 ~ 30 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.
Report an issue or suggest an edit
Spotted incorrect or dangerous information, have a correction, a new study, or a useful addition for Halazepam? Let us know. Reports are reviewed by moderators — this is not posted publicly.