4-HO-MPT Facts
Psychedelic;
Description
4-HO-MPT (4-hydroxy-N-methyl-N-propyltryptamine) — also known as meprocin — is a synthetic psychedelic of the tryptamine class. It activates serotonin receptors in the brain, producing the visual and cognitive shifts characteristic of classical psychedelics.
Subjective effects include geometric visual patterns, brightened colors, mood elevation, and physical stimulation. The experience is broadly psilocybin-like but more energetic and outward-facing — stronger in the body than in the mind, with less introspective depth than its parent compound.
4-HO-MPT produces no physical dependence, and no fatality has been attributed to it. Its most distinctive risk is an unusually strong affinity for serotonin receptors linked to heart valve damage — shared with certain diet drugs — but whether occasional use poses a real cardiac risk is unknown.[1]
Dose and durationby route · individual sensitivity varies
Starts in 20 – 60 minLasts 5 – 7 hoursAfter-effects 2 – 12 hours
Body and dependence
- Acute toxicity
- Low
- Chronic toxicity
- Moderate
- Physical dependence
- None
- Psychological dependence
- Negligible
- Withdrawal
- None recorded
- Compulsive redosing
- Negligible
Tolerance
- Builds
- Rapid
- Fully resets after
- 7 days
- Carries over to
- LSD;
psilocin; psilocybin; DMT; 4-AcO-DMT; 4-HO-MET; 4-HO-MiPT; mescaline
Effectslikely at a common dose
- Perception
- Color enhancement;
Visual drifting; Color alteration; Geometry; +32 possible, including Spatial disorientation, Visual haze / noise, Vestibular distortion - Body
- Pupil dilation;
Body high; Body scan awareness; +29 possible, including Heart rate perception changes, Nausea, Dizziness - Thinking
- Aesthetic enhancement;
Introspection enhancement; +31 possible, including Thought loops, Cognitive impairment, Suggestibility enhancement - Feeling
- Emotional enhancement;
+7 possible, including Emotional lability, Anxiety, Paranoia - Self
- none likely · 10 possible, including Derealization, Depersonalization, Communication suppression
- Time
- Time alteration;
+3 possible, including Temporal disorientation - Transpersonal
- none likely · 1 possible
- Awareness
- none likely · 5 possible
Who shouldn't take it
Combinations61 recorded
Seek help immediately if
Most difficulty is psychological (intense fear, panic, confusion) and passes with calm support — the signs below mean seek emergency help:
- Very high body temperature; hot, dry skin
- Seizures
- Chest pain; fast or irregular heartbeat
- Severe muscle rigidity, tremor, or twitching (possible serotonin syndrome)
- Cold, pale, or blue fingers/toes — severe vasoconstriction (notably NBOMe / DOx)
- Persistent vomiting; unconsciousness; uncontrollable agitation or risk of self-harm
What to do
- Stay calm and reassure — remind them they took a drug and the effect will pass
- Move to a calm, quiet, safe space with low light; reduce noise and sensory input
- Keep them from harm — they may act on fear or confusion; stay with them, don't leave them alone
- Talk them down gently; don't grab or restrain unless they're in danger
- For the medical signs above (overheating, seizure, chest pain, vasoconstriction, unresponsive) call emergency services
- If overheating, cool the body; be ready to give rescue breaths / CPR
The experience is time-limited and usually resolves with calm reassurance in a safe setting — psychological first aid, not medication. Serious physical harm is uncommon for classic psychedelics (LSD, psilocybin) but real for some potent phenethylamines (NBOMe, DOx), where hyperthermia, seizures, and vasoconstriction warrant emergency care.
988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE
References
- [1]^Glatfelter GC, Naeem M, Pham DNK, Golen JA, Chadeayne AR, Manke DR, Baumann MH (2023) Receptor Binding Profiles for Tryptamine Psychedelics and Effects of 4-Propionoxy-N,N-dimethyltryptamine in Mice — ACS Pharmacology & Translational Science doi:10.1021/acsptsci.2c00222