Summary
Daily Fen-Phen use was linked to valvular heart disease and pulmonary hypertension via 5-HT2B receptor agonism by fenfluramine's metabolite norfenfluramine; the combination was withdrawn from market in 1997. Nearly 30% of users taking the combination for up to 24 months developed abnormal valve findings. Phentermine alone does not cause valvular damage and remains available for short-term obesity treatment.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | - | - | - | 37.5+/80+mg(notrecommended)+ |
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects |
|---|---|---|---|---|---|
| Oral | 20-60 min | 30-60 min | 1-3 hrs | 3-6 hrs | 4-12 hrs |
Tolerance
Build-up
develops over days to weeks of regular use
Reset
3–7 days for acute; 1–3 weeks for full reset
Effects
Positive
- Stimulation
- Pain relief
- Physical euphoria
Negative
- Tachycardia
- Dry mouth
- Restlessness
- Insomnia
- Fatigue
- Respiratory depression
- Sedation
Positive
- Wakefulness
- Motivation enhancement
- Euphoria
- Alertness enhancement
- Cognitive euphoria
- Anxiety suppression
- Reduced anxiety
Negative
- Anxiety
- Constipation
- Talkativeness
Positive
- Warmth
- Increased music appreciation
- Increased libido
Negative
- Appetite suppression
- Light sensitivity
- Disinhibition
- Dehydration
- Dulled perception
- Internal hallucination
- Warm flush