Peptide LibraryPT-141 calculator
PT-141 is bremelanotide, FDA-approved as Vyleesi: an autoinjector that delivers a fixed 1.75 mg, approved only for acquired, generalised hypoactive sexual desire disorder in premenopausal women. Research-grade PT-141 is a lyophilised powder instead, almost always a 10 mg vial, so the marks for 1.75 mg depend on the water added. The tables show the labelled amount at common concentrations.
Full research profile: PT-141. For any other concentration, use the insulin syringe units converter.
For research use only. Not medical advice. This page does arithmetic; it does not recommend an amount.
PT-141 reconstitution chart
Concentration and micrograms per mark on a U-100 insulin syringe, by vial size and water added. The peptide amount never changes; only how concentrated it is.
| Vial | + 1 mL water | + 2 mL water | + 3 mL water |
|---|---|---|---|
| 5 mg | 5 mg/mL · 50 mcg per unit | 2.5 mg/mL · 25 mcg per unit | 1.67 mg/mL · 16.7 mcg per unit |
| 10 mg | 10 mg/mL · 100 mcg per unit | 5 mg/mL · 50 mcg per unit | 3.33 mg/mL · 33.3 mcg per unit |
Most-listed PT-141 vial sizes across vendors we track: 10 mg (28 vendors), 5 mg (2 vendors), 1 mg (1 vendor), 8 mg (1 vendor). Compare prices.
PT-141 doses from the label and trials, in syringe units
The doses reported in each cited source, converted to U-100 syringe units at common vial and water combinations. This is arithmetic on the cited figures, not a recommendation; a dash means the amount is more than one full 1 mL syringe at that concentration.
Vyleesi label: 1.75 mg as needed, no more than one dose in 24 hours and 8 per month (premenopausal women with acquired, generalised HSDD)
| Dose | 10 mg + 1 mL (10 mg/mL) | 10 mg + 2 mL (5 mg/mL) | 10 mg + 3 mL (3.33 mg/mL) |
|---|---|---|---|
| 1.75 mg | 17.5 units (0.175 mL) | 35 units (0.35 mL) | 52.5 units (0.525 mL) |
Source: VYLEESI (bremelanotide) prescribing information, DailyMed
Common questions
How many units is 1.75 mg of PT-141?
It depends on the concentration. In a 10 mg vial mixed with 2 mL of bacteriostatic water (5 mg/mL), 1.75 mg is 0.35 mL, or 35 units on a U-100 insulin syringe. With 3 mL of water instead, the same 1.75 mg is 52.5 units.
How much bacteriostatic water do you add to a 10 mg PT-141 vial?
There is no single correct volume: the amount of peptide is fixed and the water only sets the concentration. For 10 mg, 1 mL gives 10 mg/mL (100 mcg per unit), 2 mL gives 5 mg/mL (50 mcg per unit) and 3 mL gives 3.33 mg/mL (33.3 mcg per unit). More water makes each syringe mark hold less, which makes small amounts easier to measure accurately.
Are the PT-141 doses on this page recommendations?
No. They are the doses reported in the cited source (VYLEESI (bremelanotide) prescribing information, DailyMed), converted to syringe units as arithmetic. Approved products come in their own strengths and devices, and what any person should use is a decision for a licensed clinician.
What does one unit on an insulin syringe mean?
A unit is a volume mark, not an amount of drug. On a U-100 syringe 100 units fill 1 mL, so 10 units is always 0.1 mL; how much peptide those 10 units hold depends only on the concentration you mixed. U-40 syringes use 40 marks per mL, so the same volume reads as a different number of units.