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α-PiHP Facts

Stimulant; Substituted cathinone; Dopamine reuptake inhibitor

Description

α-PiHP (α-pyrrolidinoisohexanophenone) is a synthetic stimulant of the substituted cathinone class. It blocks dopamine and norepinephrine reuptake, prolonging their activity in the brain's reward and arousal circuits.[1]

Subjective effects include psychomotor stimulation, euphoria, wakefulness, focused energy, and sharp urges to redose. The experience is narrowly stimulant — intense dopamine-driven activation without the warmth or social ease of compounds that also activate serotonin.[2]

α-PiHP carries high psychological dependence liability and dose-dependent cardiovascular toxicity with no established lethal threshold.[3][4] Blood pressure elevation outlasts cocaine at comparable intranasal doses, and fatal cardiac arrest is documented; polydrug use is present in nearly all recorded fatalities.[5][6]

Dose and durationby route · individual sensitivity varies

Oral

No dose recorded for this route. The timings are not a dose guide.

Starts in 30 – 60 minLasts not recorded

Body and dependence

Acute toxicity
High
Chronic toxicity
Moderate
Physical dependence
Negligible
Psychological dependence
High
Withdrawal
Moderate
Compulsive redosing
High

Tolerance

Builds
Rapid
Fully resets after
5 days
Carries over to
α-PVP; α-PHP; MDPV; other pyrovalerone cathinones; cocaine (partial); amphetamines (partial)

Effectslikely at a common dose

Perception
none likely · 3 possible
Body
Appetite suppression; Dry mouth; Insomnia; Physical fatigue; Pupil dilation; Restlessness; Stimulation; Vasoconstriction; Wakefulness; +10 possible, including Dehydration sensation, Excessive sweating, Heart rate perception changes
Thinking
Cognitive euphoria; Cognitive fatigue; Compulsive redosing urge; Motivation suppression; Thought acceleration; +10 possible, including Cognitive dysphoria, Cognitive impairment, Decision impairment
Feeling
Euphoria; +7 possible, including Anhedonia, Anxiety, Depression
Self
none likely · 5 possible, including Craving, Compulsive repetitive behavior
Time
none likely · 1 possible

Who shouldn't take it

Absolute
Cardiovascular disease; Psychotic spectrum disorders; Bipolar disorder; Pregnancy and lactation; MAO inhibitor therapy
Relative
Seizure disorders; Severe anxiety disorders; Renal impairment; Hyperthyroidism

Combinations61 recorded

Lethal (1)
Ibogaine
Dangerous (29)
Alpha-2 adrenergic receptor antagonist; Amphetamines; Benzodiazepines, Barbiturates; Ephedrine, Pseudoephedrine; Local anesthetics; MAOIs; MDMA, Amphetamines; MDMA, MDA; NDRIs (Wellbutrin); NRIs; Opioids; SSRIs; Stimulants; Anticholinergics; Antipsychotics; Buspirone; Caffeine; Dopamine agonists; DXM; GHB, Baclofen; GHB, GBL; Ketamine, DXM, PCP; Lithium; NSAIDs; and 5 more, see full page
Caution (28)
See full page: psychedex.org/substances/alpha-pihp
Not graded (3)
Not listed never means safe.

Seek help immediately if

  • Chest pain; racing, pounding, or irregular heartbeat
  • Very high body temperature; heavy sweating; hot, flushed skin
  • Severe agitation, paranoia, panic, or confusion
  • Severe headache; muscle rigidity or twitching
  • Seizures
  • Signs of stroke — face drooping, one-sided weakness, slurred speech
  • Difficulty breathing; collapse or unconsciousness

What to do

  1. Call emergency services for chest pain, overheating, seizure, or unresponsiveness
  2. Move them to a cool, quiet place and reduce stimulation
  3. Cool the body — remove excess clothing, apply cool damp cloths, fan them
  4. Keep them calm; reassure — panic worsens the cardiovascular strain
  5. If seizing, protect from injury (don't restrain); recovery position afterward
  6. Monitor breathing and be ready to give rescue breaths / CPR

Most stimulant overdoses settle with cooling, a calm environment, and time. The medical danger is hyperthermia, cardiac events (arrhythmia, heart attack, stroke), and seizures — get help immediately if any appear.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1 · Not medical advice

References

  1. [1]
    ^Kolaczynska KE, Thomann J, Hoener MC, Liechti ME (2021) The Pharmacological Profile of Second Generation Pyrovalerone Cathinones and Related Cathinone Derivative. — International journal of molecular sciences doi:10.3390/ijms22158277
  2. [2]
    ^Weinstein A, Rosca P, Fattore L, London ED (2017) Synthetic Cathinone and Cannabinoid Designer Drugs Pose a Major Risk for Public Health — Frontiers in Psychiatry doi:10.3389/fpsyt.2017.00156
  3. [3]
    ^Gréen H, Persson M, Wikström M, Monti MC (2025) In vitro monoamine reuptake inhibition and forensic case series in Sweden of the synthetic cathinones 2-, 3-, and 4-Me-alpha-PiHP — Forensic Science International doi:10.1016/j.forsciint.2025.112657
  4. [4]
    ^Gomonit MM, Walton SE, Papsun DM, Lamb ME, Chronister CW, et al. (2026) Case series involving the synthetic cathinones alpha-PHP, alpha-PiHP, MDPHP, and MDPiHP in forensic investigations — Forensic Science International doi:10.1016/j.forsciint.2026.112917
  5. [5]
    ^De la Rosa G, Iacobone G, Papaseit E, Hladun O, Poyatos L, Caicedo DA, Argote MC, Martín S, Ventura M, Di Giorgi A, Graziano S, Pichini S, Marchei E, Farré M, Pérez-Mañá C (2025) Disposition and effects of alpha-pyrrolidinoisohexanophenone (α-PHiP) in comparison with cocaine: an observational study — Frontiers in Pharmacology doi:10.3389/fphar.2025.1728824
  6. [6]
    ^Skowronek R, Wachholz P, Bujak-Giżycka B, Celiński R, Pawlas N (2025) Use of psychoactive substances among hard coal miners during work – a case report of fatal α-PiHP and tramadol poisoning — Problems of Forensic Sciences doi:10.4467/12307483pfs.25.010.22917
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