PT-141 (Bremelanotide) Calculator

PT-141 (Bremelanotide) dosage calculator

The PT-141 (Bremelanotide) dosage calculator above converts a target dose into exact syringe units based on your vial size and how much bacteriostatic water you used to reconstitute it. PT-141 (Bremelanotide) is commonly sold in 10 mg vials. The calculator supports both U-100 and U-40 insulin syringes and flags draws that are too large for the syringe barrel or too small to measure accurately. A melanocortin receptor agonist metabolite of Melanotan-2 with activity directed at the MC4R receptor subtype. Enter your target dose in the calculator above to see the exact number of units to draw.

PT-141 (Bremelanotide) dosage chart

PT-141 (Bremelanotide) and Melanocortin peptides

PT-141 (Bremelanotide) is a Melanocortin-4 receptor agonist. A melanocortin receptor agonist metabolite of Melanotan-2 with activity directed at the MC4R receptor subtype. Other peptides in the Melanocortin class include Melanotan-2 .

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.

See all Melanocortin peptides →

How to reconstitute PT-141 (Bremelanotide)

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

Reconstituting PT-141 (Bremelanotide) is the same unit-conversion process used for any lyophilized peptide:

1. Draw your chosen volume of bacteriostatic water into a syringe.
2. Inject the bacteriostatic water slowly down the side of the PT-141 (Bremelanotide) vial — do not shoot it directly onto the powder.
3. Swirl gently until the powder fully dissolves. Do not shake.
4. Store the reconstituted vial refrigerated.
5. To dose, calculate your draw volume: divide your target dose by the concentration (vial mg ÷ water mL = mg/mL). The calculator above does this automatically.

For PT-141 (Bremelanotide) specifically, 10 mg vials are common. A typical reconstitution adds 2 mL of bacteriostatic water, producing a concentration of 5 mg/mL for the 10 mg vial size.

PT-141 (Bremelanotide) half-life and storage

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

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

Common PT-141 (Bremelanotide) dosing mistakes

Most PT-141 (Bremelanotide) draw errors are unit errors, not arithmetic errors: confusing mg with mcg (1 mg = 1,000 mcg), or reading a U-40 syringe with U-100 math — the same printed mark holds 2.5× the volume. Two more worth avoiding: leaving the vial unlabeled, so the concentration and reconstitution date are lost, and under-diluting to the point where the draw is under about one unit and can no longer be read accurately.

Each of these is covered in full in the guides: reconstitution math from first principles, U-100 vs U-40 syringes, storage and shelf life, and how to reconstitute peptides.