PT-141 (Bremelanotide) — On-Demand Protocol (3 mL = ~3.33 mg/mL)
Route: measurement (abdomen or thigh). Frequency: On-demand, at least 45 minutes before anticipated sexual activity; no more than 1 dose per 24 hours and ≤8 doses per month[1][3].
| Phase | Dose (mcg) | Units (per measurement) (mL) |
|---|---|---|
| Initial / Titration | 500–750 mcg | 15–22 units (0.15–0.22 mL) |
| Standard | 1000–1500 mcg | 30–45 units (0.30–0.45 mL) |
| Full / FDA-Approved | 1750 mcg (1.75 mg) | 52 units (0.52 mL) |
Titration: Start at a lower dose (500–750 mcg) and increase as tolerated. Nausea is common with initial use and typically diminishes with subsequent doses[2][4].
Melanotan II — Daily Protocol (3 mL = ~3.33 mg/mL)
Route: measurement (abdomen or thigh). Frequency: Once daily during loading phase; reduced frequency for maintenance[5][6].
| Week | Example amount (mcg) | Units (per measurement) (mL) |
|---|---|---|
| Week 1 | 250 mcg | 7.5 units (0.075 mL)* |
| Week 2 | 500 mcg | 15 units (0.15 mL) |
| Weeks 3–4 | 750 mcg | 22 units (0.22 mL) |
| Weeks 5+ (Loading) | 1000 mcg | 30 units (0.30 mL) |
| Maintenance | 500–1000 mcg (2–3×/week) | 15–30 units (0.15–0.30 mL) |
*For ≤10-unit (≤0.10 mL) administrations, consider 30- or 50-unit insulin syringes for improved readability.
Titration: Begin at 250 mcg and increase by 250 mcg every 5–7 days as tolerated. Nausea and flushing are common initially and typically subside with continued use[6].
Reconstitution Steps (Both Peptides)
- Draw 3.0 mL bacteriostatic water with a sterile syringe.
- Measure slowly down the vial wall; avoid foaming or direct impact on the powder.
- Gently swirl or roll until fully dissolved (do not shake).
- Label with date, peptide name, and concentration; refrigerate at 2–8 °C (35.6–46.4 °F), protected from light.
- Use reconstituted solution within approximately 1 week for optimal stability[7].
Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.
How These Peptides Work
PT-141 and Melanotan II are both synthetic cyclic peptide analogues that act on melanocortin receptors, particularly MC3R and MC4R in the central nervous system[2][5]. PT-141 (bremelanotide) is a metabolite of Melanotan II and was developed specifically for its effects on sexual function without significant pigmentation activity. It is FDA-approved for hypoactive sexual desire disorder in premenopausal women[1][3]. Melanotan II retains both melanogenic and sexual-function properties, stimulating melanin production in skin cells (melanocytes) while also activating central pathways involved in sexual arousal[5][6].