How to reconstitute PT-141 (Bremelanotide)
PT-141 (Bremelanotide) is sold as a freeze-dried powder, most often in 10 mg vials. Add bacteriostatic water, let it dissolve without shaking, and the concentration is the vial amount divided by the water: 10 mg in 2 mL is 5 mg/mL. On a U-100 insulin syringe one unit is 0.01 mL, so each unit carries 50 mcg, and a 1.75 mg dose is 35 units.
The Vyleesi label is 1.75 mg as needed, no more than one dose in 24 hours and eight a month. Nothing on this page is a dosing recommendation; the calculator converts a dose you already have into syringe units.
PT-141 (Bremelanotide) doses in syringe units (10 mg vial, 2 mL water)
| Dose | Units | mL | Doses per vial |
|---|---|---|---|
| 1 mg | 20 | 0.2 | 10 |
| 1.75 mg | 35 | 0.35 | 5 |
Vial sizes at 1.75 mg per dose
| Vial | Water | Concentration | Units per dose | Doses |
|---|---|---|---|---|
| 10 mg | 2 mL | 5 mg/mL | 35 | 5 |
The dose column is in mg. Doubling the water halves the concentration and doubles the units per dose; the number of doses in the vial never changes. If a dose comes out under 5 units, use less water so it is easier to measure. If it exceeds the syringe, use more water or a bigger syringe.
Worked example
10 mg / 2 mL = 5 mg/mL = 5,000 mcg/mL. One unit = 0.01 mL = 50 mcg. 1,750 mcg / 50 mcg per unit = 35 units. The vial holds 10,000 / 1,750 = 5 doses, which at 1 per week is about 35 days.
See the general peptide calculator for the formulas, syringe sizes, and the common mg versus mcg mistakes.