This was my second experience with 4-HO-McPT. My first experience, with 25 mg, was largely uneventful, but it was at least just strong enough for me to be able to tell that there was something going on above placebo.
4-HO-McPT
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 5 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 19 combo interactions documented
- classified Tentative
- classified Research-chemical
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 5 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 19 combo interactions documented
- classified Tentative
- classified Research-chemical
Aliases: Meprocin, 4-hydroxy-mcpt
Summary
4-HO-MPT is a research chemical with very little history of human usage and minimal scientific data on its pharmacology, metabolism, and toxicity. Legal status varies by jurisdiction; it is unscheduled in most countries but is a Class A drug in the United Kingdom under the tryptamine catch-all clause and controlled under Germany's NpSG. Use precise scales for dosing as potency varies between salt forms (freebase is approximately 25% more potent than fumarate salts).
Dose Information
Dose basis. Tentative ranges synthesized from scattered user reports and analogy to closely related 4-substituted tryptamines (e.g., 4-HO-MiPT). Treat as preliminary and titrate cautiously; start at or below threshold if untested batch. Primary provenance: community reports (Bluelight) and analogous Erowid dosing for 4-HO-MiPT. (Dose figures and this note are from Drugs.Wiki.)
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 10-15mg | 15-25mg | 25-35mg | 35mg+ |
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | Total |
|---|---|---|---|---|---|
| Oral | 19-40 min | 30-60 min | 2-3 hrs | 1-2 hrs | 3.82-6.67 hrs |
Effect Profile
5 reportsScores (1–10) curated from multiple sources:
- Effect keyword matching from PsychonautWiki catalog
- Weighted by importance: core (×3), major (×2), minor (×1)
Psychedelic
7.1
Strong+
7/10
Strong visuals and auditory effects with moderate headspace and body load
Visual Intensity
×3
9
color enhancement
drifting
pattern recognition enhancement
color shifting
depth perception distortions
after images
Headspace Depth
×3
6
thought connectivity
emotion enhancement
thought loops
time distortion
Auditory Effects
×1
8
music enhancement
auditory distortion
Body Load / Somatic Effects
×1
6
nausea
bodily pressures
increased heart rate
Based on reports from:
Import into PsychonautWiki Journal
The PsychonautWiki Journal app includes 4-HO-McPT, but its built-in data can be thinner than ours. Importing this file adds a separate "4-HO-McPT (Substance Search)" custom substance with our dose ranges, durations and tolerance, so you can log against whichever you prefer.
⬇ Download import file
Import this file as custom substances
and you get "4-HO-McPT (Substance Search)" with every
route's full dose ladder and timeline, no typing. Works on iOS and
Android (v15+); the format is confirmed by the app's
developer.
Ranges are harm-reduction guidance, not a prescription.
Tolerance
Build-up
develops rapidly after a single use
Reset
7–14 days for baseline
Tolerance Decay
Full tolerance
1d
Half tolerance
7d
Baseline
~14d
Acute tolerance: develops within a single session — the reset numbers above apply after sustained heavy use, not after one binge. Within-session tachyphylaxis usually resets largely overnight.
Pattern extrapolated from classical psychedelic tolerance: marked within 24 h, decreases substantially by 3–4 days, and approximates baseline after ~7–14 days. Data are indirect and rely on broader psychedelic literature and user reports rather than 4-HO-McPT-specific studies.
Cross-Tolerances
Effects
Aggregated from 5 Erowid experience reports
Positive Effects 3
Color Enhancement
80.0%
70%
Stimulation
60.0%
70%
Empathy
60.0%
70%
Adverse Effects 0
Combinations
Cross-Check 4-HO-McPT with another substanceCommunity Trip Reports
Anecdotal first-person accounts from Reddit, Erowid, and Bluelight. 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 3 reports 3 positive visit
Peace and Quiet 4-HO-McPT - First Trial, 60mg orally 11-14-2020 by Xorkoth Backdrop It has been an intense year for me, and the last few months in particular have been pretty rough. I have been experiencing an inordinate amount of grief and stress over the past couple of years, due to one tragic event after another.
Because I had some psychotic episodes with lysergamides, I switched to synthetic and organic tryptamines. But recently a lot of research chemical got banned in my country, and I cant risk having illegal substances. So this chemical was finally a chance to trip a bit again.
Bluelight Reference Guide
☛ Official ☚ The Big & Dandy 4-HO-McPT Thread
Welcome to the Small & Handy 4-HO-McPT Thread! 4-hydroxy-N-methyl-N-cyclopropyltryptamine This novel tryptamine has recently become widely available to those who know where to find it.
Read full thread on Bluelight →
4-HO-McPT's nerd page
Pharmacology, chemical data, effect profiles, and more
→
Helpful Links
Report an issue or suggest an edit
Spotted incorrect or dangerous information, have a correction, a new study, or a useful addition for 4-HO-McPT? Let us know. Reports are reviewed by moderators — this is not posted publicly.