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Psychedex
Facts label

4-HO-MPT Facts

Psychedelic; Substituted tryptamine; Serotonin 2A receptor agonist

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 5 mgLight10 – 20 mgCommon20 – 30 mgStrong30 – 50 mgHeavy50+ mg

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

Absolute
Current lithium therapy; Personal or family history of psychotic disorders; Pregnancy; Current MAOI therapy; Concurrent tramadol use
Relative
Pre-existing cardiac valvular disease; Current SSRI/SNRI therapy

Combinations61 recorded

Lethal (1)
MAOIs
Dangerous (17)
Dopamine agonists; Lithium; MDMA, MDA; NRIs; GHB, Baclofen; GHB, GBL; Ibogaine; Ketamine, DXM, PCP; Local anesthetics; MDMA, Amphetamines; NDRIs (Wellbutrin); Psychedelics; Salvia, Ibogaine; SNRIs; SSRIs; Stimulants; Synthetic cannabinoids
Caution (37)
See full page: psychedex.org/substances/4-ho-mpt
Not graded (6)
Not listed never means safe.

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

  1. Stay calm and reassure — remind them they took a drug and the effect will pass
  2. Move to a calm, quiet, safe space with low light; reduce noise and sensory input
  3. Keep them from harm — they may act on fear or confusion; stay with them, don't leave them alone
  4. Talk them down gently; don't grab or restrain unless they're in danger
  5. For the medical signs above (overheating, seizure, chest pain, vasoconstriction, unresponsive) call emergency services
  6. 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

psychedex.org/substances/4-ho-mpt · Version r1 · Not medical adviceValues as of
On the printout