Coming from a year-long benzo habit (2mg Diclazepam twice daily at this time) I searched for a substitute to slowly taper down with. Came across Meclonazepam (still not sure if it's the N-Methyl or 3-Methyl compound as the vendor's page wasn't 100% clear, tending to the former) and decided to swap the evening serving o...
Meclonazepam
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 2 corroborating sources
- partial dose data
- duration data present
- 27 combo interactions documented
- classified Tentative
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 2 corroborating sources
- partial dose data
- duration data present
- 27 combo interactions documented
- classified Tentative
Summary
A benzodiazepine related to clonazepam discovered by Hoffman-LaRoche in the 1960s. Potentially useful in treating schistosomiasis. Has been sold on the grey market as a recreational drug but has not seen widespread popularity.
Dose Information
| ROA | Common | Heavy |
|---|---|---|
| Oral | 3-6mg | 6-12mg+ |
Onset, Duration & After-effects
| ROA | Onset | Peak | Total |
|---|---|---|---|
| Oral | 20-60 min | 9-15 hrs | 9-15 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)
Benzodiazepine
6.6
Strong+
7/10
Strong euphoria and anxiolysis with mild cognitive impairment, low sedation
Anxiolysis
×3
8
anxiolytic
reduced anxiety
muscle relaxant
Sedation / Relaxation
×2
3
sedation
Motor / Cognitive Impairment
×1
4
amnesia
confusion
Euphoria / Mood Lift
×1
10
euphoria
cognitive euphoria
disinhibition
Based on reports from:
Tolerance
Build-up
develops over 1–4 weeks of daily use; hypnotic tolerance faster than anxiolytic tolerance
Reset
Falls after you stop, at a rate that varies from person to person. If you've been using regularly, cut down gradually with medical help rather than stopping suddenly.
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
Effects
Effect glossary — · full glossary
Positive
Negative
Positive
Negative
Positive
Negative
Combinations
Cross-Check Meclonazepam 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 1 report 1 neutral visit
Meclonazepam's nerd page
Pharmacology, chemical data, effect profiles, and more
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Helpful Links
Add to PsychonautWiki Journal
The PsychonautWiki Journal logging app doesn't include every substance. To track Meclonazepam there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:
Name
Meclonazepam
Unit
mg
Description
Meclonazepam Source: SubstanceSearch (substancesearch.com) Oral dose (mg): common 3-6 · heavy 6-12+ Oral duration: onset 0.33-1h · peak 9-15h · total 9-15h · after-effects 1-6h 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 ~ 4.5 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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