Talk:A-PiHP - PsychonautWiki


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Not to be confused with A-PHP.

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Summary sheet: A-PiHP
Chemical Nomenclature
Common names α-PiHP α-PHiP
Substitutive name 4-Methyl-1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one
Systematic name alpha-Pyrrolidinoisohexanophenone
Class Membership
Psychoactive class Stimulant
Chemical class Cathinone / Pyrrolidinophenone
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.

Threshold < 3mg
Light 3 - 10mg
Common 10 - 20mg
Strong 20 - 30mg
Heavy > 30mg
Total 1 - 3 hours
Onset 1 minutes
After effects 6 - 12 hours
Threshold < 5mg
Light 5 - 15mg
Common 15 - 30mg
Strong 30 - 50mg
Heavy > 50mg
Total 2 - 5 hours
Onset 30 - 60 minutes
After effects 6 - 12 hours

Threshold < 5mg
Light 5 - 10mg
Common 10 - 25mg
Strong 25 - 40mg
Heavy > 40mg
Total 2 - 4 hours
Onset 1 - 3 minutes
After effects 6 - 12 hours

DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.


alpha-Pyrrolidinohexiophenone (also known as α-PihP, and 4-methyl-alpha-pyrrolidinopentanophenone) is a lesser-known novel stimulant substance of the cathinone and pyrrolidinophenone classes. It is structurally related to MDPV and A-PHP and is one of the latest successors to the designer drug cathinone analog A-PVP|α-PVP].

Subjective effects such as euphoria, thought acceleration, disinhibition and ego inflation. It generally comes in the form of either a fine powder or crystallized shards that can produce powerful but short-lived euphoric stimulant effects reported to be more compulsive in nature (and strength) to vaporized methamphetamine. Like its cathinone predecessors, it is has gained notoriety for its tendency to induce compulsive redosing and addictive behaviors as well the ability to produce delusional states and psychosis when abused. The compulsivity induced in A-PiHP seems to be stronger compared to similar substances in this class, as reported by online anecdotal reports.

Very little data exists about the pharmacological properties, metabolism, and toxicity of α-PiHP. It has recently become commonly marketed as a legal, grey-market alternative to A-PHP, 3-MMC, and A-PVP, and commercially distributed through online research chemical vendors.

It is highly advised to use harm reduction practices if using this substance.


α-PHiP (also known as α-PiHP), is a stimulant drug of the cathinone class. It is a positional isomer of pyrovalerone, with the methyl group shifted from the 4-position of the aromatic ring to the 4-position of the acyl chain. In a classic 2006 study of pyrrolidinyl cathinone derivatives by Meltzer et al. at Organix, the alpha-isobutyl derivative of pyrovalerone, O-2494, was found to have the highest potency in vitro as an inhibitor of the dopamine transporter of the alpha substituted derivatives tested, however it was not until ten years later in July 2016 that α-PHiP was first identified as a designer drug, when it was reported to the EMCDDA by a forensic laboratory in Slovenia.


The mechanism of action of α-PiHP is unknown. Aside from a substantially shorter duration, it is believed to act similarly to the designer drug pentedrone and α-PVP, which both act as a potent norepinephrine-dopamine reuptake inhibitors (NDRI) without being neurotransmitter releasers,[1] although no substantial research on the pharmacology of this compound has yet been conducted.

This means it may effectively boost the levels of the norepinephrine and dopamine neurotransmitters in the brain by binding to and partially blocking the transporter proteins that normally remove those monoamines from the synaptic cleft. This allows dopamine and norepinephrine to accumulate within the brain, resulting in stimulating and euphoric effects.

Subjective effects

This compound is reported to be similar to A-PHP. More information needed.

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Physical effects

Visual effects

Cognitive effects

Multi-sensory effects

After effects

Toxicity and harm potential


This toxicity and harm potential section is a stub.

As a result, it may contain incomplete or even dangerously wrong information! You can help by expanding upon or correcting it.
Note: Always conduct independent research and use harm reduction practices if using this substance.

The toxicity and long-term health effects of recreational α-PiHP use do not seem to have been studied in any scientific context and the exact toxic dosage is unknown. This is because α-PiHP has very little history of human usage.

α-PiHP has been reported to be the cause of death in one individual. Due to the similarity of structures and the reported dosages, an attempt to compare the concentrations of α-PVP and α-PHP has been made. In the described case, functional death through intoxication of α-PiHP was accepted as the final cause of death. Other detected substances did not contribute to death due to their very likely distant administration. [2]

It is strongly recommended that one use harm reduction practices when using this substance.

Tolerance and addiction potential

As with other short-lived highly dopaminergic stimulants, the chronic use of α-PiHP can be considered highly addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.

Tolerance to many of the effects of α-PiHP develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). α-PiHP presents cross-tolerance with all dopaminergic stimulants, meaning that after the consumption of α-PiHP all stimulants will have a reduced effect.


Main article: Stimulant psychosis

α-PiHP, like other strongly dopaminergic stimulants, can result in a stimulant psychosis that may present with a variety of symptoms (e.g., paranoia, hallucinations, or delusions).[3][4] A review on treatment for amphetamine, dextroamphetamine, and methamphetamine abuse-induced psychosis states that about 5–15% of users fail to recover completely.[5][6] The same review asserts that, based upon at least one trial, antipsychotic medications effectively resolve the symptoms of acute amphetamine psychosis.[7]

Dangerous interactions

Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).

Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

  • 25x-NBOMe & 25x-NBOH - 25x compounds are highly stimulating and physically straining. Combinations with A-PiHP should be strictly avoided due to the risk of excessive stimulation and heart strain. This can result in increased blood pressure, vasoconstriction, panic attacks, thought loops, seizures, and heart failure in extreme cases.
  • Alcohol - Combining alcohol with stimulants can be dangerous due to the risk of accidental over-intoxication. Stimulants mask alcohol's depressant effects, which is what most people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects will be left unopposed, which can result in blackouts and severe respiratory depression. If mixing, the user should strictly limit themselves to only drinking a certain amount of alcohol per hour.
  • DXM - Combinations with DXM should be avoided due to its inhibiting effects on serotonin and norepinephrine reuptake. There is an increased risk of panic attacks and hypertensive crisis, or serotonin syndrome with serotonin releasers (MDMA, methylone, mephedrone, etc.). Monitor blood pressure carefully and avoid strenuous physical activity.
  • MDMA - Any neurotoxic effects of MDMA are likely to be increased when other stimulants are present. There is also a risk of excessive blood pressure and heart strain (cardiotoxicity).
  • MXE - Some reports suggest combinations with MXE may dangerously increase blood pressure and increase the risk of mania and psychosis.
  • Dissociatives - Both classes carry a risk of delusions, mania and psychosis, and these risk may be multiplied when combined.
  • Stimulants - A-PiHP may be dangerous to combine with other stimulants like cocaine as they can increase one's heart rate and blood pressure to dangerous levels.
  • Tramadol - Tramadol is known to lower the seizure threshold[8] and combinations with stimulants may further increase this risk.

Serotonin syndrome risk

Combinations with the following substances can cause dangerously high serotonin levels. Serotonin syndrome requires immediate medical attention and can be fatal if left untreated.

Legal status

  • Brazil: As of September 7, 2018, all cathinone analogues are controlled substances considered illegal to possess, use and distribute. This was made possible due to a blanket ban law appended to Portaria SVS/MS nº 344.[10]
  • Canada: α-PiHP is a Schedule 1 drug in Canada.
  • Estonia:α-PiHP is a I Schedule drug and was officially banned on September 4, 2023. Before that date, α-PiHP would have just fallen under VI Schedule cathinone blanket ban.[11]
  • Italy: The President of the Republic of Italy classified cathinone and all structurally derived analogues (including pyrovalerone analogues) as Narcotics in January 2012. [12]
  • United Kingdom: is a Class B drug in the United Kingdom as a result of the cathinone catch-all clause.[13]
  • United States: α-PiHP has been assigned to Schedule I on a Temporary Placement basis. This order, which extends the temporary scheduling order that DEA previously issued for these substances (84 FR 34291, July 18, 2019), is effective July 18, 2021 and expires on July 18, 2022. .[14] As such, the sale or the use of this compound is prohibited.

See also

External links


  2. (PubMed) |
  4. Treatment for amphetamine psychosis | [1]
  5. Treatment for amphetamine psychosis | [2]
  6. Hofmann FG (1983). A Handbook on Drug and Alcohol Abuse: The Biomedical Aspects (2nd ed.). New York: Oxford University Press. p. 329. ISBN 9780195030570.
  7. Treatment for amphetamine psychosis | [3]
  8. Talaie, H.; Panahandeh, R.; Fayaznouri, M. R.; Asadi, Z.; Abdollahi, M. (2009). "Dose-independent occurrence of seizure with tramadol". Journal of Medical Toxicology. 5 (2): 63–67. doi:10.1007/BF03161089. eISSN 1937-6995. ISSN 1556-9039. OCLC 163567183. 
  9. Gillman, P. K. (2005). "Monoamine oxidase inhibitors, opioid analgesics and serotonin toxicity". British Journal of Anaesthesia. 95 (4): 434–441. doi:10.1093/bja/aei210 . eISSN 1471-6771. ISSN 0007-0912. OCLC 01537271. PMID 16051647. 
  10. New blanket ban on synthetic illegal drugs is approved (Portuguese) |
  11. (Estonian)
  13. United Kingdom. (2010). Misuse of Drugs Act 1971 (S.I. 2010/1207). London: The Stationery Office Limited. Retrieved February 9, 2018, from
  14. {{cite web | title = Schedules of Controlled Substances Extension | url = | publisher = Drug Enforcement Administration | access-date = 2022-04-22 |.
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