PT-141 (Bremelanotide) Reconstitution Calculator

What is PT-141 (Bremelanotide)?

PT-141, also known as bremelanotide, is a cyclic heptapeptide analog of alpha-melanocyte stimulating hormone. It is a metabolite of Melanotan-2 and was developed as a melanocortin receptor agonist with activity particularly at MC4R. Published clinical research has studied PT-141 in the context of sexual function, and the compound has been approved by the FDA under the brand name Vyleesi for a specific sexual-function indication in premenopausal women. Research-grade PT-141 sold by chemical supply companies is distinct from the approved branded product and is labeled for laboratory use only.

Common vial sizes

Research vendors typically offer PT-141 in 10 mg lyophilized vials. Reconstitution with 2–5 mL of bacteriostatic water is commonly reported.

• 10 mg vial

Reconstitution examples

Worked examples showing exactly what a given vial, bacteriostatic water volume, and target dose produce in syringe units. All math is from the same calculator above.

• 10 mg vial + 2 mL bacteriostatic water → 5000 mcg/mL concentration.
  A 1000 mcg dose = 20 units on a u-100 insulin, 1 ml (100 units) (0.2 mL).
• 10 mg vial + 3 mL bacteriostatic water → 3333.33 mcg/mL concentration.
  A 1000 mcg dose = 30 units on a u-100 insulin, 1 ml (100 units) (0.3 mL).
• 10 mg vial + 3 mL bacteriostatic water → 3333.33 mcg/mL concentration.
  A 1750 mcg dose = 52.5 units on a u-100 insulin, 1 ml (100 units) (0.525 mL).
• 10 mg vial + 5 mL bacteriostatic water → 2000 mcg/mL concentration.
  A 1750 mcg dose = 87.5 units on a u-100 insulin, 1 ml (100 units) (0.875 mL).

Storage & shelf life

Lyophilized PT-141 is typically stored refrigerated. Reconstituted solutions are commonly refrigerated and protected from light.

Reported half-life

Published pharmacokinetic studies report a plasma half-life of approximately 2 hours for PT-141 / bremelanotide.