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Reconstitution, dosing & half-life math — done right, in seconds.

PT-141 Reconstitution Calculator

PT-141 is a melanocortin receptor agonist (bremelanotide). This page shows how to reconstitute it and read the result on a syringe — the calculator does the arithmetic for you.

Status: The prescription drug Vyleesi is FDA-approved; research-chem PT-141 is not the approved product and is not for human use.

The math

Concentration = vial ÷ water  ·  Units = (dose ÷ concentration) × 100

PT-141 is a lyophilized peptide reconstituted with bacteriostatic water.

Worked example

Illustrative numbers only — not a dose recommendation.

Example
Vial10 mg
Bacteriostatic water2 mL
Concentration5 mg/mL
Each 10 units (0.1 mL) contains500 mcg

How to use the calculator

  1. Open the calculator and enter your PT-141 vial size.
  2. Enter your bacteriostatic water volume, then your dose.
  3. Read off the units to draw and doses per vial.
Open the calculator

Planning a full cycle? Work out vials, syringes & swabs →

Frequently asked questions

How do I reconstitute PT-141?
Add bacteriostatic water to the lyophilized vial to reach a concentration you can measure. For example, 10 mg in 2 mL of water gives 5 mg/mL, so each 10 units (0.1 mL) on a U-100 syringe contains about 500 mcg of PT-141. Swirl gently rather than shaking.
How many units of PT-141 do I draw?
Divide your intended dose by the concentration to get the volume in mL, then multiply by 100 for a U-100 syringe. The calculator does this automatically once you enter your vial size, water volume and dose.
What vial sizes does PT-141 come in?
PT-141 is commonly supplied as 5 mg, 10 mg. The amount in the vial does not change with how much water you add — water only sets the concentration.
Is PT-141 approved for human use?
The prescription drug Vyleesi is FDA-approved; research-chem PT-141 is not the approved product and is not for human use. This calculator only performs arithmetic on the numbers you enter and does not recommend any dose.