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4-AcO-DMT Facts

Psychedelic; Substituted tryptamine; Serotonin 2A receptor agonist

Description

4-AcO-DMT (O-acetylpsilocin) — also known as psilacetin — is a synthetic psychedelic of the tryptamine class. It activates serotonin receptors in the brain, producing the visual and cognitive shifts of classical psychedelics.[1][2]

Subjective effects include geometric visual patterns, brightened colors, emotional deepening, introspection enhancement, and ego dissolution at high doses. The experience is warm and body-centered — widely described as indistinguishable from psilocybin mushrooms,[3] and less stimulating than LSD.

4-AcO-DMT produces no physical dependence, and a single dose causes rapid tolerance that makes compulsive use unlikely.[4] The primary danger is psychological — high doses can produce panic, paranoia, and identity disruption, and combining it with serotonin-raising drugs risks a dangerous overactivation of the serotonin system.

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 5 mgLight5 – 15 mgCommon15 – 25 mgStrong25 – 45 mgHeavy45+ mg

Starts in 15 – 40 minLasts 4 – 7 hoursAfter-effects 4 – 48 hours

Body and dependence

Acute toxicity
Low
Chronic toxicity
Low
Physical dependence
None
Psychological dependence
Negligible
Withdrawal
None recorded
Compulsive redosing
Negligible

Tolerance

Builds
Rapid
Fully resets after
7 days
Carries over to
psilocybin; psilocin; LSD; DMT; mescaline

Effectslikely at a common dose

Perception
Music enhancement; Color enhancement; Visual drifting; Color alteration; Geometry; Visual breathing; Holotropic state; +30 possible, including Visual haze / noise, Spatial disorientation, Vestibular distortion
Body
Pupil dilation; Body high; +34 possible, including Nausea, Insomnia, Temperature dysregulation
Thinking
Introspection enhancement; +32 possible, including Language suppression, Memory suppression, Thought loops
Feeling
Emotional enhancement; +8 possible, including Anxiety, Emotional lability, Paranoia
Self
none likely · 11 possible, including Derealization, Depersonalization, Ego inflation
Time
Time alteration; +4 possible, including Temporal disorientation
Transpersonal
none likely · 1 possible
Awareness
Personal insight; +3 possible

Who shouldn't take it

Absolute
Psychotic disorders; Bipolar disorder; Pregnancy; Concurrent tramadol use; Concurrent MAOI use
Relative
Cardiovascular disease; Seizure disorders

Combinations61 recorded

Lethal (1)
MAOIs
Dangerous (19)
MDMA, MDA; Alpha-2 adrenergic receptor antagonist; Dopamine agonists; DXM; GHB, Baclofen; GHB, GBL; Ibogaine; Ketamine, DXM, PCP; Lithium; Local anesthetics; MDMA, Amphetamines; NDRIs (Wellbutrin); NRIs; Psychedelics; Salvia, Ibogaine; SNRIs; SSRIs; Stimulants; Synthetic cannabinoids
Caution (37)
See full page: psychedex.org/substances/4-aco-dmt
Not graded (4)
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

Version r1 · Not medical advice

References

  1. [1]
    ^Glatfelter GC, Pottie E, Partilla JS, Sherwood AM, et al. (2022) Structure-Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice — ACS Pharmacology and Translational Science doi:10.1021/acsptsci.2c00177
  2. [2]
    ^Zhai W, Li L, Zhao J, Xiang P, Liu M, Shi Y, Dang Y (2022) Tentative identification of in vitro metabolites of O-acetylpsilocin (psilacetin, 4-AcO-DMT) by UHPLC-Q-Orbitrap MS — Drug Testing and Analysis doi:10.1002/dta.3255
  3. [3]
    ^Shulgin (1997) Tryptamines I Have Known and Loved (TiHKAL)
  4. [4]
    ^Vargas-Perez H, Minauro-Sanmiguel F, Ting-A-Kee R, Grieder TE, Méndez-Díaz M, Próspero-García O, van der Kooy D (2024) Rewarding Effects of the Hallucinogen 4-AcO-DMT Administration and Withdrawal in Rats: A Challenge to the Opponent-Process Theory — Neuroscience Letters doi:10.1016/j.neulet.2023.137597
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