Somatropin (HGH) vs PT-141 (Bremelanotide)
Side-by-side comparison of key properties, dosing, and research.
Growth Hormone PeptidesAnti-Aging & Longevity
Somatropin (HGH)Sexual Health & Libido
PT-141 (Bremelanotide)- Summary
- Somatropin is recombinant human growth hormone (rhGH), identical in structure to the 191-amino acid pituitary-derived growth hormone. It is FDA-approved for growth hormone deficiency, short stature, and wasting conditions. Off-label, it is widely explored for body composition, anti-aging, and performance enhancement, though significant risks accompany unsupervised use.
- PT-141 (Bremelanotide) is a cyclic peptide melanocortin receptor agonist that enhances sexual desire and arousal through central nervous system mechanisms. It is FDA-approved as Vyleesi for premenopausal women with hypoactive sexual desire disorder (HSDD).
- Half-Life
- 2-3 hours (subcutaneous); 20-30 minutes (intravenous)
- 2–3 hours
- Admin Route
- Subcutaneous, Intramuscular (less common)
- SubQ
- Research
- —
- —
- Typical Dose
- 0.15-0.3 mg/day (adults); titrated to IGF-1 levels
- 0.5–1.75 mg
- Frequency
- Once daily
- As needed (not daily)
- Key Benefits
- Increases lean muscle mass and reduces body fat (particularly visceral)
- Restores growth hormone deficiency (FDA-approved)
- Improves bone mineral density
- Enhances exercise capacity and recovery
- Supports skin thickness and collagen synthesis
- Improves lipid profile in GHD patients
- Explored for anti-aging and cellular regeneration
- Enhances sexual desire and libido in both men and women
- Improves arousal through central nervous system activation
- Effective for psychological erectile dysfunction
- Works for female sexual arousal disorder
- May improve sexual satisfaction and intensity
- Fast-acting — effects within 45–60 minutes
- FDA-approved for HSDD in premenopausal women
- Side Effects
- Fluid retention and edema (common, dose-dependent)
- Carpal tunnel syndrome
- Joint and muscle pain
- Insulin resistance and elevated blood glucose
- +3 more
- Nausea (most common — 40% of users in clinical trials)
- Facial flushing and warmth
- Transient blood pressure changes (typically increase then normalize)
- Headache
- +2 more
- Stacks With
- —
- —