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4-AcO-MiPT

4-acetoxy-N-methyl-N-isopropyltryptamine

Overview

4-AcO-MiPT (4-acetoxy-N-methyl-N-isopropyltryptamine) — mipracetin — is a synthetic psychedelic of the tryptamine class. It is the acetate ester prodrug of 4-HO-MiPT (miprocin), a close structural analog of 4-AcO-DMT. It activates serotonin receptors in the brain, producing the visual and cognitive shifts characteristic of classical psychedelics.[1]

4-AcO-MiPT (4-acetoxy-N-methyl-N-isopropyltryptamine) — mipracetin — is a synthetic psychedelic of the tryptamine class. It is the acetate ester prodrug of 4-HO-MiPT (miprocin), distinguished from 4-AcO-DMT by its asymmetric N-alkyl substitution. 4-AcO-MiPT is a 5-HT₂A receptor partial agonist via its active metabolite, producing its effects by activating serotonergic signaling cascades in the cortex.[1]

Entity
4-AcO-MiPT
PSX-0060
4-AcO-MiPT 2D chemical structure
Open Beta

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NoticeAll →
•1 lethal interaction(all →)
Common names4-AcO-MiPT, Mipracetin, O-Acetylmiprocin
Substitutive name4-acetoxy-N-methyl-N-isopropyltryptamine
Threshold
< 5 mg
Light
10 – 15 mg
Common
15 – 20 mg
Strong
20 – 35 mg
Heavy
35+ mg
12340 h2 h4 h6 h
1Onset
20m–1h2Come-up
1h–2h3Peak
1.5h–3h4Resolution
1h–2hAftereffects2h–4h
Total4h–8h
Builduprapid
Full reset7 days
Cross-tol.
psilocybin, psilocin, LSD +3 more
Absolute4 entries
psychotic disorderspregnancy and breastfeedingconcurrent MAOI useconcurrent tramadol use
Relative3 entries
cardiovascular diseasebipolar disorderconcurrent SSRI/SNRI use
Dosage varies by body weight, tolerance & metabolism · Not medical advice · Terms
See an error? Suggest correction
See an error? Suggest correction

Alexander Shulgin first evaluated the parent compound 4-HO-MiPT in self-experiments in 1979, describing it as the most interesting in a series of psilocin analogs.[2] The acetate ester form appeared on online research chemical markets in the late 2000s, sold as a legal alternative to psilocybin mushrooms.[3] It remains unscheduled in the United States and Canada, though controlled in several European countries, and no clinical research has been conducted.

Subjective effects include geometric visual patterns, synesthesia, music enhancement, heightened touch, emotional intensification, and euphoria. The experience is more sensory and erotically charged than psilocybin — strong visuals and body awareness without the heavy psychological weight.[2] Thought loops, anxiety during onset, and nausea are characteristic unwanted effects.

4-AcO-MiPT does not produce physical dependence, and no lethal dose data exist for any species. The dominant risk is psychological — panic and psychosis in vulnerable individuals — with a sharp escalation when combined with MAOIs or tramadol, which can trigger life-threatening serotonin overload.[4] No clinical studies have been published; understanding rests on receptor binding data, structural analogy, and community reports.

History[edit]

Discovery

4-HO-MiPT (miprocin), the active form of 4-AcO-MiPT, was first synthesized by David Repke in a systematic study of psilocin analogs.[5] Alexander Shulgin evaluated it by 1979, calling it the most interesting compound in his series and describing 12 mg as "richly insightful and highly erotic".[2] The acetate ester was subsequently prepared alongside 4-AcO-DMT, with acetylation improving chemical stability over the free phenol form.[3]

Research chemical emergence

4-AcO-MiPT appeared on online markets in the late 2000s as a fumarate salt, marketed as a legal alternative to psilocybin mushrooms.[3] Formal pharmacological study arrived in 2023, when Kozell et al. published the first binding and potency data for both the prodrug and its active metabolite.[1] A patent covering crystalline forms of miprocin filed the same year signals growing commercial interest, though no clinical program has been announced.[6]

Chemistry[edit]

Structural class

4-AcO-MiPT belongs to the 4-substituted tryptamine family — indole alkaloids defined by an oxygen-bearing group at the 4-position of the indole ring.[7]

It is the acetate ester prodrug of 4-HO-MiPT, paralleling the relationship between psilocybin and psilocin.[8] Its molecular formula is C₁₆H₂₂N₂O₂ (274.36 g/mol), and it is distributed commercially as the fumarate salt.[3]

Pharmacology[edit]

Mechanism of action

4-AcO-MiPT is a prodrug. After ingestion, the body cleaves the acetate ester to release 4-HO-MiPT (miprocin), the pharmacologically active form — the same conversion that turns psilocybin into psilocin.[1] The active metabolite then activates serotonin receptors, particularly the signaling pathway responsible for psychedelic effects across the tryptamine class.[9]

The active metabolite also engages other serotonin receptor subtypes, each contributing to the overall experience.[1] It has moderate affinity for the SERT — unlikely to drive the primary experience at typical doses, but clinically relevant in combination with other serotonergic drugs.[1]

Pharmacokinetics

No human pharmacokinetic data exist specifically for 4-AcO-MiPT. Based on related compounds, ester hydrolysis is the primary metabolic step, followed by liver processing.[10] By analogy to Psilocin, oral bioavailability is estimated around 50%, with peak effects at 2–4 hours and a half-life of 1.5–4 hours.[11]inferred

Neuroscience[edit]

Where it acts

No neuroimaging data exist for 4-AcO-MiPT. By class analogy, the active metabolite disrupts the brain's default mode network — the system that maintains the ordinary sense of self — and loosens the filtering of incoming signals.[12] The result is perceptual intensification, looser associative thinking, and visual pattern generation.

Why it matters

Serotonergic psychedelics trigger changes in brain structure and connectivity that may persist after the acute experience.[12] 4-AcO-MiPT's partial activation of serotonin receptors falls within the range associated with this kind of brain rewiring, though this has not been directly tested.

Subjective Effects[edit]

Summary

4-AcO-MiPT produces a sensory, body-aware psychedelic experience. The defining quality is an erotic and tactile richness — the body comes alive, music deepens, and the visual field fills with geometric form.[2] Where most psychedelics turn attention inward, this one opens outward toward sensation.

Within the 4-substituted tryptamine family, 4-AcO-MiPT sits between 4-AcO-DMT and the diisopropyl structural analog 4-AcO-DiPT in intensity and duration.[3] Compared to psilocybin, it is more visually active, less sedating, and less psychologically heavy — with a sensual quality that users consistently distinguish from the introspective depth of classic mushrooms.[2]

Alexander Shulgin first evaluated 4-HO-MiPT in self-experiments in 1979, describing it as the most interesting compound in a series of oxygen-substituted MiPT analogs.[2] The acetate ester form entered online research chemical markets in the late 2000s alongside other 4-substituted tryptamine prodrugs.[3] It remains unscheduled in the United States and Canada, with no clinical investigation conducted to date.

Subjective effects include geometric visual patterns, synesthesia, thought connectivity, emotional intensification, and music enhancement. The experience is reported as more sensory and erotically charged than psilocybin, with a pronounced visual component and less sedation — a quality Shulgin noted in the parent compound.[2] Thought loops, anxiety during onset, and transient nausea are characteristic unsought effects.

4-AcO-MiPT is not considered habit-forming; rapid tolerance via 5-HT₂A downregulation makes compulsive redosing self-limiting.[4] The primary risk is psychological — acute distress, paranoid ideation, or psychosis precipitation in predisposed individuals — amplified by co-administration with serotonergic agents such as MAOIs or tramadol.[5] No clinical studies, toxicity data, or human pharmacokinetics have been published; the current understanding rests entirely on receptor binding data, structural analogy, and community reports.

History[edit]

Discovery

4-HO-MiPT (miprocin), the active metabolite of 4-AcO-MiPT, was first synthesized by David Repke as part of a systematic investigation of psilocin analogs with varied N,N-dialkyl substituents.[6] Alexander Shulgin evaluated 4-HO-MiPT in self-experiments by 1979, describing 12 mg as "richly insightful and highly erotic" and identifying it as the most interesting member of his oxygen-substituted MiPT series.[2] The acetate ester prodrug was subsequently prepared alongside 4-AcO-DMT and 4-AcO-DET, with the acetyloxy group improving chemical stability over the oxidation-prone free phenol.[3]

Research chemical emergence

4-AcO-MiPT appeared on online research chemical markets in the late 2000s, typically as the fumarate salt, marketed alongside other 4-substituted tryptamine prodrugs as a legal alternative to psilocybin mushrooms.[3] No institutional research program or therapeutic development pathway has been identified for the compound. A 2023 patent covering crystalline forms of miprocin suggests emerging commercial interest in the pharmacological target, though no clinical program has been announced.[7]

Pharmacological characterization

Formal pharmacological study proceeded slowly. Crystal structures of the active metabolite were reported in 2019 and 2020.[8][9] The pivotal dataset appeared in 2023, when Kozell et al. published binding affinity and functional potency data for both 4-AcO-MiPT and 4-OH-MiPT at serotonin receptors.[1] In the same year, Wallach et al. identified Gq-pathway signaling as the key predictor of psychedelic potential across the tryptamine class.[4] Hill et al. (2025) reported behavioral effects in rodent models following DEA designation of 4-OH-MiPT as a tryptamine derivative of concern.[10]

Chemistry[edit]

Structural class

4-AcO-MiPT belongs to the 4-substituted tryptamine family — indole alkaloid derivatives defined by oxygenated substitution at the 4-position of the indole ring. It is the acetate ester prodrug of 4-HO-MiPT, paralleling the relationship between psilocybin and psilocin. The defining structural feature is its asymmetric N-methyl-N-isopropyl substitution on the ethylamine side chain, placing it between the compact 4-AcO-DMT (N,N-dimethyl) and the bulkier 4-AcO-DiPT (N,N-diisopropyl) in structural space.[11]

Molecular properties

Molecular formulaC₁₆H₂₂N₂O₂
Molecular weight274.36 g/mol

The molecule comprises an indole bicyclic ring system with an acetyloxy group at C-4 and a 2-(N-methyl-N-isopropylamino)ethyl chain at C-3.[12] The acetate ester at C-4 is the site of hydrolytic cleavage that converts the prodrug to its active 4-hydroxy metabolite in vivo. The asymmetric tertiary amine generates greater steric bulk than 4-AcO-DMT but less than 4-AcO-DiPT, influencing receptor binding geometry.

Stereochemistry

4-AcO-MiPT contains no chirality centers. The molecule is achiral — no enantiomers or diastereomers exist, and all preparations consist of a single molecular species.[12]

Physical properties

No published data on melting point, solubility, or chemical stability of 4-AcO-MiPT exist in either free base or salt form. The compound has been commercially distributed as the fumarate salt.[3]

Crystal structure data exist only for the active metabolite 4-HO-MiPT: Chadeayne et al. determined the fumarate monohydrate structure in 2019,[8] followed by a bis(miprocinium) fumarate salt form in 2020.[9] These apply to the metabolite reference standard, not 4-AcO-MiPT itself.

Pharmacology[edit]

Mechanism of action

4-AcO-MiPT functions as a prodrug. The 4-acetoxy ester undergoes hydrolysis in vivo to yield 4-HO-MiPT (miprocin), the pharmacologically active form. This is supported by the approximately 7-fold difference in serotonin receptor binding between the parent ester and the free hydroxyl metabolite,[1] and corroborated by animal studies showing 4-hydroxy tryptamines are consistently more potent than their 4-acetoxy counterparts.[13]

The primary target is the serotonin 5-HT₂A receptor, where 4-OH-MiPT acts as a partial agonist through the Gq signaling pathway.[1] Gq-pathway activation at 5-HT₂A — rather than beta-arrestin2 recruitment — predicts psychedelic potential across the tryptamine class.[4]

Secondary targets include the 5-HT₂C receptor (near-full agonism) and 5-HT₁A (moderate agonism), both contributing to the broader experiential profile.[1] Downstream effects are expected to include glutamate receptor modulation and neuroplasticity cascades, consistent with the serotonergic psychedelic class.[14]

The active metabolite also shows moderate affinity at the SERT (SERT).[1] At typical doses this is unlikely to drive the primary experience, but it becomes clinically relevant in combination with other serotonergic agents.

Pharmacokinetics

No human pharmacokinetic data exist specifically for 4-AcO-MiPT. All parameters below are inferred from structural analogs.

Metabolic studies of the related 4-AcO-DiPT in human liver cells identified ester hydrolysis as the primary pathway, followed by glucuronidation, sulfation, and minor oxidative metabolism.[15] By analogy, 4-AcO-MiPT is expected to undergo the same ester cleavage to yield 4-OH-MiPT. This parallels the well-characterized conversion of psilocybin to psilocin.[16]

Reference data from psilocin pharmacokinetics suggest oral bioavailability around 50%, peak plasma levels at 2–4 hours, and an half-life of 1.5–4 hours.[16] These values provide an approximate frame, but the bulkier N-isopropyl group of 4-OH-MiPT may alter clearance rates.inferred

Neuroscience[edit]

Where it acts

No direct neuroimaging data exist for 4-AcO-MiPT. By class inference from its 5-HT₂A partial agonist pharmacology, the active metabolite is expected to act on layer V cortical pyramidal neurons, disrupting default mode network integrity and reducing thalamocortical gating.[14] The result is increased global connectivity and neural entropy — experienced as perceptual intensification, loosened associative thinking, and visual pattern generation.

The co-engagement of 5-HT₂A and 5-HT₁A receptors produces the balance characteristic of tryptamine psychedelics: perceptual amplification driven by 5-HT₂A alongside a contemplative, anxiolytic undercurrent from 5-HT₁A.[14]

Why it matters

Serotonergic psychedelics activate neuroplasticity cascades downstream of 5-HT₂A — promoting structural changes in neurons that may underlie persisting psychological shifts after acute experiences.[14] 4-AcO-MiPT's partial agonism falls within the range associated with psychoplastogenic potential, though this has not been directly tested. The REBUS framework (Relaxed Beliefs Under Psychedelics) offers context: partial 5-HT₂A agonism would be expected to moderately loosen the precision of prior beliefs, permitting new sensory and cognitive patterns without complete ego dissolution.

Subjective Effects[edit]

Summary

4-AcO-MiPT produces a classical tryptamine psychedelic experience defined by its sensory richness. Community reports consistently emphasize a pronounced erotic and tactile quality, strong music enhancement, and vivid geometric patterning — creating an experience that feels more outward-facing and body-aware than the introspective depths of psilocybin.[2] Set and setting substantially shape the experience: supportive, comfortable environments tend to draw out the sensual and euphoric character, while unfamiliar or anxious contexts amplify thought loops and somatic discomfort. Across the dose range, lower doses emphasize color enhancement and mood lift, while higher doses produce full visual field distortion, synesthesia, and transpersonal states.[3]

Within the 4-substituted tryptamine family, 4-AcO-MiPT occupies a middle position: shorter and lighter than the diisopropyl structural analog 4-AcO-DiPT, more visually active and less sedating than 4-AcO-DMT, and qualitatively distinct from both by its reported sensory emphasis. No controlled comparison studies exist — all positioning derives from community cross-reports.

Effect Grid

Dose Level:
Description

At common doses (15–20 mg oral), the full psychedelic experience manifests: pronounced color enhancement and brightness alteration, visual drifting and symmetrical texture repetition across surfaces, tracers behind moving objects, and emerging internal hallucinations with eyes closed. Auditory distortion and music enhancement become prominent. Thought connectivity intensifies, with pattern recognition enhancement and conceptual thinking producing novel associations.

Emotional enhancement is marked — music, social interactions, and natural environments may feel deeply meaningful. Spontaneous body sensations are more pronounced, with the characteristic tingling/rushing quality. Pupil dilation is clearly visible. Yawning is common. The experience requires 4–8 hours of commitment; sleep is difficult until effects fully resolve.

Modeled from the effect's dose-dependence curve — not per-substance measurements.

Perception(54)likelihood · intensity
Geometry
likely
Color enhancement
likely
Music enhancement
possible
Visual drifting
possible
Visual breathing
possible
Color alteration
possible
Brightness alteration
possible
Environmental patterning
possible
Double vision!
rare

Visual breathing · Color alteration · Brightness alteration · Environmental patterning · Touch enhancement · Depth perception distortion · Perspective distortion · Symmetrical texture repetition · Tracers · Auditory enhancement · Ganzfeld effect · Holotropic state · Light sensitivity · Peripheral misidentification · Peripheral vision distortion · Proprioceptive distortion · Sound sensitivity · Spatial disorientation · Visual haze / noise · Visual melting · Visual morphing · Auditory distortion · Synesthesia · After-images · Visual diffraction · Visual acuity enhancement · Auditory misinterpretation · Dreaming enhancement · Vestibular distortion · Visual magnification · Sleep-transition hallucinations · Visual processing acceleration · Tinnitus · Visual acuity suppression · Olfactory enhancement · Taste enhancement · Flashbacks · Internal hallucinations · Object transformations · Environmental orbism / cubism · External hallucinations · Object activation · Visual recursion · Auditory hallucinations · Perspective hallucinations · Visual flipping · Visual scenery slicing · Shadow people · Persisting hallucinations

Touch enhancement · Depth perception distortion · Perspective distortion · Symmetrical texture repetition · Tracers · Auditory enhancement · Ganzfeld effect · Holotropic state · Light sensitivity · Peripheral misidentification · Peripheral vision distortion · Proprioceptive distortion · Sound sensitivity · Spatial disorientation · Visual haze / noise · Visual melting · Visual morphing · Auditory distortion · Synesthesia · After-images · Visual diffraction · Visual acuity enhancement · Auditory misinterpretation · Dreaming enhancement · Vestibular distortion · Visual magnification · Sleep-transition hallucinations · Visual processing acceleration · Tinnitus · Visual acuity suppression · Olfactory enhancement · Taste enhancement · Flashbacks · Internal hallucinations · Object transformations · Environmental orbism / cubism · External hallucinations · Object activation · Visual recursion · Auditory hallucinations · Perspective hallucinations · Visual flipping · Visual scenery slicing · Shadow people · Persisting hallucinations

Body(47)likelihood · intensity
Pupil dilation
likely
Stimulation
possible
Body high
possible
Spontaneous body sensations
possible
Body scan awareness
possible
Appetite suppression
possible
Motor control impairment!
possible
Temperature dysregulation!
possible
Vasoconstriction!
rare

Spontaneous body sensations · Body scan awareness · Appetite suppression · Wakefulness · Bodily lightness · Dry mouth · Insomnia · Laughter fits · Nausea · Physical fatigue · Tactile euphoria · Tingling / electric sensations · Vibrations / buzzing · Bodily heaviness · Body schema distortion · Dizziness · Excessive sweating · Heart rate perception changes · Muscle relaxation · Muscle tension · Restlessness · Yawning · Bodily pressures · Breathing alteration · Bruxism · Dehydration sensation · Headache · Increased urination · Involuntary body movements · Kundalini-like energy · Nystagmus (eye wobbles) · Salivation · Sexual arousal enhancement · Trembling · Vasoconstriction · Sedation · Nasal congestion · Watery eyes · Diarrhea · Vomiting · Bodily dissociation · Tactile hallucination

Wakefulness · Bodily lightness · Dry mouth · Insomnia · Laughter fits · Nausea · Physical fatigue · Tactile euphoria · Tingling / electric sensations · Vibrations / buzzing · Bodily heaviness · Body schema distortion · Dizziness · Excessive sweating · Heart rate perception changes · Muscle relaxation · Muscle tension · Restlessness · Yawning · Bodily pressures · Breathing alteration · Bruxism · Dehydration sensation · Headache · Increased urination · Involuntary body movements · Kundalini-like energy · Nystagmus (eye wobbles) · Salivation · Sexual arousal enhancement · Trembling · Sedation · Nasal congestion · Watery eyes · Diarrhea · Vomiting · Bodily dissociation · Tactile hallucination

Thinking(43)likelihood · intensity
Aesthetic enhancement
possible
Introspection enhancement
possible
Openness enhancement
possible
Novelty enhancement
possible
Cognitive euphoria
possible
Cognitive flexibility
possible
Decision impairment!
possible
Suggestibility enhancement!
possible
Compulsive redosing urge!
rare

Novelty enhancement · Cognitive euphoria · Cognitive flexibility · Increased nature relatedness · Thought connectivity · Pattern recognition enhancement · Conceptual thinking · Immersion enhancement · Cognitive impairment · Creativity enhancement · Humor enhancement · Multiple thought streams · Thought acceleration · Memory suppression · Analysis enhancement · Focus enhancement · Information processing enhancement · Cognitive fatigue · Memory fragmentation · Synchronicity · Thought disorganization · Thought loops · Language enhancement · Analysis suppression · Cognitive dysphoria · Compulsive redosing urge · Confusion · Focus suppression · Information processing suppression · Language suppression · Memory replays · Motivation suppression · Thought deceleration · Motivation enhancement · Thought organization · Delusions of sobriety · Amnesia · Delusions

Increased nature relatedness · Thought connectivity · Pattern recognition enhancement · Conceptual thinking · Immersion enhancement · Cognitive impairment · Creativity enhancement · Humor enhancement · Multiple thought streams · Thought acceleration · Memory suppression · Analysis enhancement · Focus enhancement · Information processing enhancement · Cognitive fatigue · Memory fragmentation · Synchronicity · Thought disorganization · Thought loops · Language enhancement · Analysis suppression · Cognitive dysphoria · Confusion · Focus suppression · Information processing suppression · Language suppression · Memory replays · Motivation suppression · Thought deceleration · Motivation enhancement · Thought organization · Delusions of sobriety · Amnesia · Delusions

Feeling(12)likelihood · intensity
Emotional enhancement
possible
Emotional lability
possible
Empathy enhancement
possible
Euphoria
possible
Simultaneous emotions
possible
Catharsis
possible
Anxiety
possible
Paranoia!
rare
Mania!
rare

Euphoria · Simultaneous emotions · Catharsis · Anxiety · Anxiety suppression · Dysphoria · Irritability

Anxiety suppression · Dysphoria · Irritability

Self(21)likelihood · intensity
Emotional susceptibility
possible
Derealization
possible
Disinhibition
possible
Social connection
possible
Trust enhancement
possible
Communication enhancement
possible
Sociability enhancement
possible
Compulsive repetitive behavior!
rare
Self-control suppression!
v.rare

Social connection · Trust enhancement · Communication enhancement · Sociability enhancement · Depersonalization · Flow state · Automaticity · Communication suppression · Ego inflation · Sociability suppression · Social disconnection · Boundary dissolution · Identity alteration · Cognitive disconnection · Ego dissolution · Telepathic feelings

Depersonalization · Flow state · Automaticity · Communication suppression · Ego inflation · Sociability suppression · Social disconnection · Boundary dissolution · Identity alteration · Cognitive disconnection · Ego dissolution · Telepathic feelings

Time(6)likelihood · intensity
Time alteration
possible
Present-moment absorption
possible
Temporal disorientation
possible
Deja vu
possible
Jamais vu
rare
Time cessation
v.rare

Time cessation

Transpersonal(12)likelihood · intensity
Unity and interconnectedness
possible
Existential realization
rare
Noetic insight
rare
Transpersonal feelings
v.rare
Entity contact
v.rare
Non-dual awareness
v.rare
Transpersonal memory access
v.rare
Transpersonal visions
v.rare
Cessation
v.rare

Non-dual awareness · Transpersonal memory access · Transpersonal visions · Cessation · Death-rebirth sequence · Voidness · Near-death experience

Death-rebirth sequence · Voidness · Near-death experience

Awareness(7)likelihood · intensity
Personal insight
possible
Cognitive dissonance
possible
Lucid dreaming enhancement
possible
Lucidity enhancement
possible
Mindfulness enhancement
possible
Reality testing impairment!
v.rare
Recursive awareness
v.rare

Mindfulness enhancement · Recursive awareness

report missing effect
Likelihood: how common this effect is at the selected dose level.This effect has safety implications — review before use.

Timeline

Safety[edit]

Harm
Acute toxicity
Low
Chronic toxicity
Low
Withdrawal
None
Tolerance buildup
rapid
Tolerance reset
7 days
Dependence
Physical
None
Psychological
Negligible
Compulsive redosing
Negligible
Dose escalation
Negligible
Cross-tol.
psilo · psilocin · LSD
Risk Shape
TOXPHYPSYWDRREDTOL

Toxicity

No lethal dose data exist for 4-AcO-MiPT in any species, and no adverse event or overdose case specifically attributable to it has been identified.[13]safety citation needed Class-level data show tryptamine intoxications can cause rapid heart rate, elevated blood pressure, elevated body temperature, and seizures — particularly when combined with serotonergic drugs or MAOIs.[14]

Heart and circulation

No cardiovascular toxicity data exist for 4-AcO-MiPT. Community reports note pupil dilation consistent with mild sympathomimetic activation. Mild, temporary increases in heart rate and blood pressure are expected by class analogy.safety citation needed

Organ toxicity

No liver, kidney, or other organ toxicity data have been published.safety citation needed The absence of data reflects insufficient study, not confirmed safety.

Psychological Risks

No controlled data on psychological risks exist. By class inference from serotonergic psychedelics:

  • Acute psychological distress: anxiety, panic, paranoia, and dysphoric crisis can occur at any dose but are more likely above 20 mg, in unsupported settings, or in predisposed individuals
  • Psychosis precipitation: serotonergic psychedelics can trigger psychotic episodes in individuals with personal or family history of psychotic spectrum disorderssafety citation needed
  • HPPD: Persistent perceptual changes after the experience are reported across the psychedelic class; no specific reports are linked to 4-AcO-MiPTsafety citation needed
  • Thought loops: Reported among cognitive effects, contributing to acute distress at higher doses

The compound's partial activation of serotonin receptors suggests a ceiling on effect intensity relative to full agonists, but this does not eliminate psychological risk.inferred

Tolerance & Dependence

Tolerance builds rapidly via serotonin downregulation and resets fully within approximately 7 days.[9]inferred Cross-tolerance with other serotonergic psychedelics — including LSD, psilocybin, and DMT — is expected via the shared mechanism.[9] 4-AcO-MiPT is not habit-forming; no physical dependence, withdrawal, or escalating use patterns have been documented.[15]

1LETHAL
19DANGEROUS
37CAUTION
4UNGRADED
61 rules0 SOURCE-VERIFIED2 EDITOR-REVIEWED

Serotonin syndrome risk

The primary interaction danger is serotonin syndrome — a life-threatening response involving overheating, muscle rigidity, and seizures — triggered when 4-AcO-MiPT is combined with agents that increase serotonin activity.[1]

Tramadol: Dangerous combination. Tramadol blocks serotonin reuptake while acting as an opioid.[16] Combined with 4-AcO-MiPT's serotonin activation, this creates significant serotonin syndrome risk.[4][17]

MAOIs: Dangerous combination. Monoamine oxidase inhibitors prevent serotonin from being broken down. Combined with a serotonin receptor activator, this causes severe amplification of both psychedelic effects and serotonin toxicity.[14]safety citation needed

SSRIs/SNRIs: chronic use attenuates psychedelic effects via serotonin receptor downregulation. Acute combination increases serotonin syndrome risk.[4]

Metabolic interactions

By analogy to psilocin, liver enzymes (CYP2D6 and CYP3A4) are expected to process the active metabolite.[11] Inhibitors of these enzymes may increase plasma levels, intensifying and prolonging effects.inferred

Cannabis

The interaction with cannabis is uncharacterized. No published data exist to assess risk or effect modification.citation needed

Contraindications

7 known
4ABSOLUTE
3RELATIVE
  • Psychotic disorders and schizophrenia spectrum (personal or family history): Absolute contraindicationsafety citation needed
  • Concurrent MAOI use: Absolute contraindication — severe serotonin syndrome risk[14]
  • Concurrent tramadol use: Absolute contraindication — serotonin syndrome risk[4]
  • Bipolar disorder: Relative contraindication — may trigger manic episodessafety citation needed
  • Heart conditions: Relative contraindication — sympathomimetic effects expectedsafety citation needed
  • Pregnancy and breastfeeding: Standard precautionary contraindication — no reproductive data existsafety citation needed

All contraindications are class-level inference. No substance-specific studies have been conducted.

Harm Reduction[edit]

Forms & Identification

Reagent ResultsNot recorded+ add reagent results
AppearanceNot recorded+ add appearance
Red FlagsNot recorded+ add red flags

4-AcO-MiPT circulates as a fumarate salt powder. Standard reagent tests (Marquis, Mecke) confirm tryptamine presence but cannot distinguish it from 4-AcO-DMT or other 4-substituted analogs. Quantitative testing via HPLC or mass spectrometry through drug checking services is the only reliable way to confirm identity and purity.

Active doses are measured in milligrams. A milligram-capable scale (±1 mg) is the minimum standard for accurate dosing. For doses below 15 mg, volumetric dosing from a prepared solution provides additional safety margin.

Guidelines

  • Test substance identity with reagent kits; use drug checking services where available
  • Weigh doses on a milligram-capable scale — never estimate by eye
  • Start with a low dose (10–15 mg) to assess individual sensitivity before exploring higher ranges
  • Allow at minimum 7 days between experiences to permit full tolerance reset
  • Prepare the space: comfortable temperature, accessible water, familiar music, minimal obligations for the following day
  • Eat lightly 2–3 hours before dosing to reduce nausea during onset
  • Have a trusted sitter present, particularly at doses above 20 mg
  • Keep a phone accessible for emergencies but minimize digital stimulation during the experience

Set & Setting

The sensory and emotionally amplifying character of 4-AcO-MiPT makes environment choice significant. Comfortable, familiar, private settings draw out the tactile and euphoric qualities. Unfamiliar or socially demanding environments increase the likelihood of anxiety, thought loops, and somatic discomfort.

A trusted sitter — someone sober and informed about psychedelic crisis support — is advisable at any dose above the low range, particularly for those without prior tryptamine experience.

Aftercare & integration. The days after a 4-AcO-MiPT experience may bring a gentle afterglow or mild fatigue. Prioritize sleep, hydration, and light nutrition.

For meaningful or challenging experiences, journaling within 24–48 hours captures insights before they fade. Discussing the experience with a trusted friend or integration-focused therapist helps process difficult emotional material. Avoid major life decisions in the immediate aftermath — allow several days for perspective to stabilize.

If disturbing perceptual changes, intrusive thoughts, or persistent anxiety continue beyond a few days, seek professional support from a provider familiar with psychedelic experiences.

Recovery & Support

4-AcO-MiPT does not produce physical dependence or withdrawal. Psychological patterns — using psychedelics to avoid processing difficult emotions, or increasing frequency despite diminishing returns — are best addressed through honest self-assessment.

If psychedelic use has become a way to escape rather than explore, or if experiences are causing more distress than insight, reducing frequency or pausing is appropriate. Peer support communities, psychedelic integration circles, and therapists specializing in altered states can provide structure.

Recovery resources, crisis lines, and support pathways → View all

Emergency Response

Recognizing an emergency:

Most difficult moments during 4-AcO-MiPT experiences are uncomfortable but not medically dangerous. Seek immediate help if:

  • The person expresses intent to harm themselves or others
  • Sustained confusion with complete disconnection from reality (unable to respond to name, unaware of surroundings)
  • Seizure activity
  • Chest pain or irregular heartbeat
  • Body temperature noticeably elevated (hot to touch, not sweating)

Immediate steps:

  • Move the person to a quiet, safe space
  • Speak calmly and simply — "You took a substance. You are safe. This will end."
  • Do not restrain unless there is immediate danger of self-harm
  • If unconscious, place in the recovery position
  • Call emergency services if any red flag above is present or if you are unsure

What to tell the dispatcher:

Name the substance (4-AcO-MiPT or "a synthetic tryptamine psychedelic"), approximate dose, time taken, and current symptoms. Good Samaritan laws in many jurisdictions protect people who call for help during drug emergencies.

Safety[edit]

Harm
Acute toxicity
Low
Chronic toxicity
Low
Withdrawal
None
Tolerance buildup
rapid
Tolerance reset
7 days
Dependence
Physical
None
Psychological
Negligible
Compulsive redosing
Negligible
Dose escalation
Negligible
Cross-tol.
psilo · psilocin · LSD
Risk Shape
TOXPHYPSYWDRREDTOL

Toxicity

No lethal dose data exist for 4-AcO-MiPT in any species, and no therapeutic index can be calculated. No published case reports of adverse events, overdose, or death specifically attributable to this compound have been identified.safety citation needed A 2022 systematic review of novel psychoactive substance adverse events from 2017–2020 found no confirmed cases involving 4-AcO-MiPT or its metabolite.[17]

Class-level data provide the only available context: tryptamine NPS intoxications can include rapid heart rate, elevated blood pressure, elevated body temperature, seizures, and serotonin syndrome — particularly when combined with serotonergic agents or MAOIs.[18] Polydrug use complicates attribution of effects to individual compounds in emergency presentations.[19]

Heart and circulation

No cardiovascular toxicity data specific to 4-AcO-MiPT exist. Community reports note pupil dilation consistent with mild sympathomimetic activation. By class analogy, mild transient increases in heart rate and blood pressure are expected at psychedelic doses.safety citation needed

Organ toxicity

No liver, kidney, or other organ toxicity data have been published. The absence of data reflects insufficient study, not confirmed safety.safety citation needed

Psychological Risks

No controlled data on psychological risks exist. By class inference from serotonergic psychedelics:

  • Acute psychological distress: anxiety, panic, paranoia, and dysphoric crisis can occur at any dose but are more likely above 20 mg, in unsupported settings, or in predisposed individuals
  • Psychosis precipitation: Serotonergic psychedelics can trigger psychotic episodes in individuals with personal or family history of psychotic spectrum disorderssafety citation needed
  • HPPD: Hallucinogen persisting perception disorder is reported across the psychedelic class; no specific reports are linked to 4-AcO-MiPTsafety citation needed
  • Thought loops: Reported among cognitive effects, contributing to acute distress at higher doses

The compound's partial agonism at 5-HT₂A suggests an intrinsic ceiling on effect intensity relative to full agonists, but this does not eliminate psychological risk.inferred

Tolerance & Dependence

Rapid tolerance develops via 5-HT₂A downregulation following agonist exposure.[4] Community consensus places tolerance onset at near-immediate, with full reset within approximately 7 days.inferred Cross-tolerance with other serotonergic psychedelics — including LSD, psilocybin, and DMT — is expected via the shared mechanism.[4]

4-AcO-MiPT is not considered habit-forming. No evidence of physical dependence, withdrawal, or escalating use patterns has been documented. Substituted tryptamines show stimulus generalization with other psychedelics in animal models, but this reflects shared receptor pharmacology rather than compulsive self-administration.[13]

1LETHAL
19DANGEROUS
37CAUTION
4UNGRADED
61 rules0 SOURCE-VERIFIED2 EDITOR-REVIEWED

Serotonin syndrome risk

The primary interaction concern is serotonin syndrome when combined with agents that increase synaptic serotonin. As a 5-HT₂A agonist with moderate SERT affinity, the active metabolite already engages multiple serotonergic pathways.[1]

Tramadol: Dangerous combination. Tramadol inhibits serotonin reuptake while acting as an opioid agonist.[20] Combined with 5-HT₂A agonism, this creates clinically significant serotonin syndrome risk.[5] Tramadol-induced serotonin syndrome is documented in published case series.[21]

MAOIs: Dangerous combination. MAO-A inhibitors block serotonin degradation; combined with a 5-HT₂A agonist, severe potentiation of both psychedelic effects and serotonin toxicity is expected.[18]safety citation needed

SSRIs/SNRIs: Chronic SSRI use attenuates psychedelic effects via 5-HT₂A downregulation. Acutely, the combination increases serotonin syndrome risk.[5]

Metabolic interactions

By analogy to psilocin, the active metabolite is presumed to undergo metabolism via CYP2D6 and CYP3A4.[16] Inhibitors of these enzymes may increase plasma levels, potentially intensifying and prolonging effects.inferred

Cannabis

The interaction with cannabis is uncharacterized. No published data exist to assess risk or effect modification.citation needed

Contraindications

7 known
4ABSOLUTE
3RELATIVE

No published contraindication data specific to 4-AcO-MiPT exist. The following are inferred from pharmacological class:

  • Psychotic disorders and schizophrenia spectrum (personal or family history): Absolute contraindicationsafety citation needed
  • Concurrent MAOI use: Absolute contraindication — severe serotonin syndrome risk[18]
  • Concurrent tramadol use: Absolute contraindication — serotonin syndrome risk[5]
  • Bipolar disorder: Relative contraindication — may trigger manic episodessafety citation needed
  • Heart conditions: Relative contraindication — sympathomimetic effects expectedsafety citation needed
  • Pregnancy and breastfeeding: Standard precautionary contraindication — no reproductive data existsafety citation needed

All contraindications are class-level inference. No substance-specific studies have been conducted.

Harm Reduction[edit]

Forms & Identification

Reagent ResultsNot recorded+ add reagent results
AppearanceNot recorded+ add appearance
Red FlagsNot recorded+ add red flags

4-AcO-MiPT typically circulates as a fumarate salt powder. The compound has no widely established reagent testing profile distinct from other 4-substituted tryptamines — Marquis and Mecke reagents will indicate tryptamine presence but cannot distinguish 4-AcO-MiPT from 4-AcO-DMT or other acetylated analogs. Quantitative testing (HPLC or mass spectrometry via drug checking services) is the only reliable method to confirm identity and purity.

Because active doses are measured in milligrams, precision weighing is essential. A milligram-capable scale (±1 mg) is the minimum standard; volumetric dosing from a prepared solution provides additional safety margin for doses below 15 mg.

Guidelines

  • Test substance identity with reagent kits; use drug checking services where available
  • Weigh doses on a milligram-capable scale — never estimate by eye
  • Start with a low dose (10–15 mg) to assess individual sensitivity before exploring higher ranges
  • Allow at minimum 7 days between experiences to permit full tolerance reset
  • Prepare the space: comfortable temperature, accessible water, familiar music, minimal obligations for the following day
  • Eat lightly 2–3 hours before dosing to reduce nausea during onset
  • Have a trusted sitter present, particularly at doses above 20 mg
  • Keep a phone accessible for emergencies but minimize digital stimulation during the experience

Set & Setting

The reported sensory and emotionally amplifying character of 4-AcO-MiPT makes environment choice particularly significant. Comfortable, familiar, and private settings support the compound's tendency toward tactile and sexual arousal enhancement. Unfamiliar or socially demanding environments increase the likelihood of anxiety, thought loops, and somatic discomfort.

A trusted sitter — someone sober and informed about psychedelic crisis support — is advisable for any dose above the low range, especially for those without prior tryptamine experience.

Aftercare & integration. The days following a 4-AcO-MiPT experience may include a gentle afterglow or mild fatigue. Prioritize sleep, hydration, and light nutrition.

For meaningful or challenging experiences, journaling within 24–48 hours captures insights before they fade. Discussing the experience with a trusted friend or integration-focused therapist can help process difficult emotional material. Avoid making major life decisions in the immediate aftermath — allow several days for perspective to stabilize.

If disturbing perceptual changes, intrusive thoughts, or persistent anxiety continue beyond a few days, seek professional support from a provider familiar with psychedelic experiences.

Recovery & Support

4-AcO-MiPT does not produce physical dependence or withdrawal. Psychological patterns of use — using psychedelics to avoid processing difficult emotions, or increasing frequency despite diminishing returns — are best addressed through honest self-assessment.

If psychedelic use has become a way to escape rather than explore, or if experiences are causing more distress than insight, reducing frequency or pausing use is appropriate. Peer support communities, psychedelic integration circles, and therapists specializing in altered states can provide structure for this process.

Recovery resources, crisis lines, and support pathways → View all

Emergency Response

Recognizing an emergency:

Most difficult moments during 4-AcO-MiPT experiences are uncomfortable but not medically dangerous. Seek immediate help if:

  • The person expresses intent to harm themselves or others
  • Sustained confusion with complete disconnection from reality (unable to respond to name, unaware of surroundings)
  • Seizure activity
  • Chest pain or irregular heartbeat
  • Body temperature noticeably elevated (hot to touch, not sweating)

Immediate steps:

  • Move the person to a quiet, safe space
  • Speak calmly and simply — "You took a substance. You are safe. This will end."
  • Do not restrain unless there is immediate danger of self-harm
  • If unconscious, place in the recovery position
  • Call emergency services if any red flag above is present or if you are unsure

What to tell the dispatcher:

Name the substance (4-AcO-MiPT or "a synthetic tryptamine psychedelic"), approximate dose, time taken, and current symptoms. Good Samaritan laws in many jurisdictions protect people who call for help during drug emergencies.

Frequently asked questions

How long does 4-AcO-MiPT last?

Total duration by route of administration — Oral: 4 – 8 hours. Ranges vary with dose and individual factors; see the duration table for onset, peak, and after-effect phases.

Where can I find dosage information for 4-AcO-MiPT?

Psychedex publishes a dosage table for 4-AcO-MiPT on this page covering these routes of administration: oral. Dose values are presented only in that table, always alongside their route of administration.

What are dangerous combinations with 4-AcO-MiPT?

The highest-severity documented interactions for 4-AcO-MiPT: MAOIs (Lethal), Alpha-2 adrenergic receptor antagonist (Dangerous), Dopamine agonists (Dangerous), DXM (Dangerous), GHB, Baclofen (Dangerous). See the interactions section for the full list with mechanisms and severity levels.

Is 4-AcO-MiPT addictive?

Psychedex records tolerance and dependence data rather than a yes/no rating. Recorded tolerance indicators for 4-AcO-MiPT: tolerance builds rapid; full reset takes 7 days; cross-tolerance develops with psilocybin, psilocin, LSD, DMT, 4-AcO-DMT, mescaline. See the article's dependence and safety sections for recorded dependence data.

experience reports

No experience reports yet. Be the first to contribute.

First-person accounts of subjective effects, timing, and outcomes — submitted for harm reduction.

references

  1. [1] 
    ^abcdefKozell LB, Eshleman AJ, Swanson TL, Bloom SH, Wolfrum KM, et al. (2023) Pharmacologic Activity of Substituted Tryptamines at 5-HT2A, 5-HT2C, 5-HT1A Receptors and SERT — Journal of Pharmacology and Experimental Therapeutics doi:10.1124/jpet.122.001454
  2. [2] 
    ^abcdeShulgin (1997) TiHKAL: The Continuation
  3. [3] 
    ^abcdefghiPsychonautWiki editorial (2025) Serotonin toxicity of serotonergic psychedelics: multi-jurisdiction legal and drug-drug interaction review Link
  4. [4] 
    ^abcdMalcolm B, Thomas K (2022) Serotonin toxicity of serotonergic psychedelics — Psychopharmacology doi:10.1007/s00213-021-05876-x
  5. [5] 
    ^Repke (1985) Psilocin analogs II. Synthesis of 3-[2-(dialkylamino)ethyl]-, 3-[2-(N-methyl-N-alkylamino)ethyl]-, and 3-[2-(cycloalkylamino)ethyl]indol-4-ols
  6. [6] 
    ^Chadeayne AR et al. (2023) US11780808B2 - Crystalline bis-miprocin fumarate Link

references

  1. [1] 
    ^abcdefgKozell LB, Eshleman AJ, Swanson TL, Bloom SH, Wolfrum KM, et al. (2023) Pharmacologic Activity of Substituted Tryptamines at 5-HT2A, 5-HT2C, 5-HT1A Receptors and SERT — Journal of Pharmacology and Experimental Therapeutics doi:10.1124/jpet.122.001454
  2. [2] 
    ^abcdShulgin (1997) TiHKAL: The Continuation
  3. [3] 
    ^abcdefghiPsychonautWiki editorial (2025) Serotonin toxicity of serotonergic psychedelics: multi-jurisdiction legal and drug-drug interaction review Link
  4. [4] 
    ^abcdeWallach J, Cao AB, Calkins MM, Heim AJ, Lanham JK, et al. (2023) Identification of 5-HT2A receptor signaling pathways associated with psychedelic potential — Nature Communications doi:10.1038/s41467-023-44016-1
  5. [5] 
    ^abcdMalcolm B, Thomas K (2022) Serotonin toxicity of serotonergic psychedelics — Psychopharmacology doi:10.1007/s00213-021-05876-x
  6. [6] 
    ^Repke (1985) Psilocin analogs II. Synthesis of 3-[2-(dialkylamino)ethyl]-, 3-[2-(N-methyl-N-alkylamino)ethyl]-, and 3-[2-(cycloalkylamino)ethyl]indol-4-ols
Last updated Jun 4, 2026