4F-MPH is a potent functional stimulant with a steep dose-response curve requiring careful dosing. It is 2-3 times more potent than methylphenidate as a dopamine and norepinephrine reuptake inhibitor. Effects are characterized by long-lasting stimulation with variable euphoria that typically manifests only in the first 1-2 hours. The substance is known for promoting focus and productivity at lower doses, but higher doses can cause forced stimulation, anxiety, and physical discomfort. Use proper harm reduction practices and start with low doses due to individual sensitivity variations.
Also known as: 4-fmph, 4-fl-mph, 4-fluoro-mph, Para‑fluoromethylphenidate, PF‑MPH, 4F-methylphenidate
Classification
Chemical: Phenidate
Psychoactive: Stimulant
Tag: Habit-Forming
Tag: Research-Chemical
Tag: substituted phenidate
Tag: Tentative
Effects
Stimulation
Teeth Grinding
Nausea
Vasoconstriction
Spontaneous Bodily Sensations
Pupil Dilation
Focus Enhancement
Thought Organization
Motivation Enhancement
Cognitive Euphoria
Analysis Enhancement
Wakefulness
Increased Music Appreciation
Appetite Suppression
Dehydration
Increased Libido
Light Sensitivity
Increased Sexuality
Routes of Administration
Oral
Dosage
Threshold: 1-2.5 mg
Light: 5-10 mg
Common: 10-15 mg
Strong: 15-20 mg
Heavy: 20-25 mg
Duration
Onset: 0.33-0.75 h
Comeup: 0.5-1 h
Peak: 2-4 h
Offset: 1-2 h
After Effects: 5-10 h
Total Duration: 4-8 h
Insufflated
Dosage
Threshold: 1-2 mg
Light: 2.5-7.5 mg
Common: 7.5-10 mg
Strong: 10-15 mg
Heavy: 18 mg+
Duration
Onset: 0.03-0.17 h
Comeup: 0.17-0.33 h
Peak: 0.25-1 h
Offset: 1-2 h
After Effects: 4-16 h
Total Duration: 4-6 h
Harm Reduction
Check interactions before mixing substances, pay attention to dose spacing and hydration, and treat all dosage guidance as approximate rather than guaranteed safe.
Sources
Substance data is aggregated from the following public harm-reduction and reference sources.
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4-Fluoromethylphenidate - przewodnik po substancji DrugsPRO
4-Fluoromethylphenidate: 4F-MPH is a potent functional stimulant with a steep dose-response curve requiring careful dosing. It is 2-3 times more potent than methylphenidate as a dopamine and norepinephrine reuptake inhibitor. Effects are characterized by long-lasting stimulation with variable euphor
