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PT-141 (Bremelanotide) dosage and protocol
Last reviewed Oct 7, 2026. Editorial policy
US regulatory status: FDA-approved drug
Libido-enhancing peptide that works on the nervous system for sexual arousal in both men and women
- Vial size: 10 mg
- Reconstitution: 3 mL bacteriostatic water
- Concentration: 3.33 mg/mL
- Administration: subcutaneous
Research areas
- Sexual Enhancement
- Libido
- Erectile Function
- Female Sexual Dysfunction
Quick start
- Reconstitute: Add 3.0 mL bacteriostatic water to the 10 mg vial for about 3.33 mg/mL
- Typical dose: 1-4 mg as needed, 45-60 minutes before activity (approved dose is 1.75 mg)
- Easy measuring: At 3.33 mg/mL, 1 unit = 0.01 mL = 33.3 mcg on a U-100 syringe; 1 mg is 30 units and 1.75 mg is about 52.5 units
- Storage: Unreconstituted at -20°C; refrigerate after mixing
Dosing protocol
| Phase | Dose | Frequency | Volume |
|---|---|---|---|
| Standard | 1000-4000 | 45-60 mins before intercourse | 0.2-0.8 |
How it works
PT-141, known clinically as bremelanotide, is a cyclic heptapeptide derived from melanotan II. It activates melanocortin receptors, mainly MC4R and MC3R, in the hypothalamus. Rather than acting on blood flow like PDE5 inhibitors, it is thought to influence central pathways for sexual motivation, including increasing dopamine release in the medial preoptic area. Bremelanotide is FDA-approved (as Vyleesi, 2019) for premenopausal women with acquired, generalised hypoactive sexual desire disorder not caused by another condition or medication. The approved regimen is 1.75 mg by subcutaneous autoinjector at least 45 minutes before anticipated sexual activity, no more than one dose in 24 hours and no more than eight doses per month. In the phase 3 RECONNECT trials it produced statistically significant but modest improvements in desire and a reduction in related distress compared with placebo. Earlier phase 2 work in men with erectile dysfunction, including some who did not respond to sildenafil, showed erectile responses, but development for men did not proceed to approval. Nausea was the most common side effect in the women's trials, and transient blood pressure increases led to a recommendation against use in uncontrolled hypertension or cardiovascular disease.
Units chart for a 10 mg vial
| Water added | Strength | 1 unit = | 1 mg |
|---|---|---|---|
| 1 mL | 10 mg/mL | 100 mcg | 10 units |
| 2 mL | 5 mg/mL | 50 mcg | 20 units |
| 3 mL | 3.33 mg/mL | 33.3 mcg | 30 units |
Units on a U-100 insulin syringe (100 units = 1 mL).
Pages for each vial size and water volume
Reconstitution steps
- Draw 2.0 mL bacteriostatic water with a sterile syringe
- Inject slowly down the vial wall; avoid foaming
- Gently swirl/roll until dissolved (do not shake)
- Label with reconstitution date and refrigerate at 2–8°C, protected from light; use within 30 days
Storage
Evidence: FDA label. From the US prescribing information of the approved product. It applies to that product only.
Applies to: Vyleesi autoinjector (label).
- Powder or unopened: Not a powder: single-use autoinjector. Store at or below 25 °C (77 °F). Do not freeze.
- Mixed or in use: Single use: throw the autoinjector away after the injection.
- Use within: no tested number
- Light: Protect from light.
Vials sold as "PT-141" are not Vyleesi and have no tested storage data once mixed.
Most reconstituted peptides are kept in the refrigerator (2–8 °C) and used within about 28 days. That is a convention, not tested data: the 28 days comes from the USP <797> limit for opened multiple-dose containers, which is about sterility, not about whether the peptide stays intact.
Sources: Vyleesi prescribing information (DailyMed); Crestigen: Peptide storage and handling guide
Store unreconstituted at -20°C. Refrigerate after mixing
Important notes
- Derived from Melanotan II
- Works on MC3R and MC4R in hypothalamus for CNS arousal
- Take 45-60 minutes before intercourse
- Effects last 24-72 hours
- Maximum one dose per 24 hours to avoid desensitization
- Can cause nausea, flushing
- Do NOT combine with PDE5 inhibitors - risk of priapism
- Can be given via subcutaneous injection or nasal spray
Supplies
- Bacteriostatic water (2mL)
- Insulin syringes
- Alcohol swabs
- Intranasal spray (alternative)