4F-PHP - Substance Search

Summary TheDrug.Wiki TripSit

4F-PHP is a potent synthetic stimulant in the pyrrolidinophenone/cathinone class, structurally related to alpha-PHP with a fluorine substitution at the 4-position of the phenyl ring. First identified in 2017, it produces strong stimulation and euphoria with high compulsivity. User reports suggest it is slightly less prone to extreme side effects than alpha-PVP but still carries significant risks including cardiovascular strain, anxiety, paranoia, and stimulant psychosis.

Dose Information TheDrug.Wiki TripSit

ROA	Light	Common	Strong	Heavy
Insufflated	5-15mg	15-30mg	30-50mg	50mg+

Light Common Strong Heavy

Onset, Duration & After-effects TheDrug.Wiki TripSit

ROA	Onset	Comeup	Peak	Offset	After Effects	Total
Oral	10-30 min	20-40 min	1-3 hrs	2-4 hrs	4-24 hrs	3.5-8.2 hrs
Insufflated	2-10 min	10-20 min	1-2 hrs	1-3 hrs	4-24 hrs	2.2-5.5 hrs

Effect Profile

1 reports

Scores (1–10) curated from multiple sources:

Effect keyword matching from PsychonautWiki catalog
Weighted by importance: core (×3), major (×2), minor (×1)

Full methodology

Stimulant 5.4

Moderate+ 5/10

Strong euphoria and anxiety/jitters with moderate focus, low stimulation

Stimulation / Energy ×3

3

stimulation

Euphoria / Mood Lift ×2

10

physical euphoria euphoria cognitive euphoria motivation enhancement

Focus / Productivity ×2

7

focus enhancement thought acceleration motivation enhancement

⚠ Anxiety / Jitters ×1

10

anxiety paranoia increased heart rate teeth grinding vasoconstriction sweating

Based on reports from:

Erowid Experience Reports PsychonautWiki 4F-PHP

Tolerance

Build-up develops over days to weeks of regular use

Reset 3–7 days for acute; 1–3 weeks for full reset

Tolerance Decay

Full tolerance 2d Half tolerance 3d Baseline ~10d

Tolerance develops rapidly with repeated doses/binges and partially subsides over several days; full return to baseline typically requires 1–2+ weeks after heavy use. Data are largely anecdotal from user communities and extrapolated from related pyrrolidinophenones.