About PT-141
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). Biogenesis Labs supplies PT-141 as lyophilized powder in 10 mg vials, for laboratory research use only.
Research-grade vials: PT-141 10 mg. Every batch is independently tested — see the Certificates of Analysis.
How to calculate PT-141 concentration
concentration (mg/mL) = PT-141 in vial (mg) ÷ diluent volume (mL)
- A 10 mg PT-141 vial with 2 mL of bacteriostatic water is 5.00 mg/mL (5,000 mcg/mL).
- On a U-100 syringe, 100 units = 1 mL, so each unit holds 50.0 mcg.
- Use 3 mL instead and the same vial reads 3.33 mg/mL, or 33.3 mcg per unit. More diluent lowers the concentration; the PT-141 in the vial does not change.
For U-40 syringes (40 units = 1 mL), divide mcg/mL by 40 instead of 100. The calculator above switches between both scales.
PT-141 reconstitution chart
Concentration for each Biogenesis Labs vial size across common diluent volumes. “In 10 units” is the PT-141 contained in 10 units on a U-100 syringe (0.10 mL).
PT-141 10 mg vial
| Diluent | Concentration | mcg / mL | Per U-100 unit | In 10 units | U-100 units per 1 mg |
|---|---|---|---|---|---|
| 1 mL | 10.00 mg/mL | 10,000 | 100.0 mcg | 1.00 mg | 10.00 |
| 1.5 mL | 6.67 mg/mL | 6,667 | 66.7 mcg | 0.67 mg | 15.00 |
| 2 mL | 5.00 mg/mL | 5,000 | 50.0 mcg | 0.50 mg | 20.00 |
| 2.5 mL | 4.00 mg/mL | 4,000 | 40.0 mcg | 0.40 mg | 25.00 |
| 3 mL | 3.33 mg/mL | 3,333 | 33.3 mcg | 0.33 mg | 30.00 |
| 4 mL | 2.50 mg/mL | 2,500 | 25.0 mcg | 0.25 mg | 40.00 |
| 5 mL | 2.00 mg/mL | 2,000 | 20.0 mcg | 0.20 mg | 50.00 |
Values are rounded. Figures describe solution concentration only and are not recommendations.
Reconstituting and storing a PT-141 vial
Let the sealed vial reach room temperature, swab both stoppers, and run the diluent slowly down the inside wall of the vial rather than onto the powder. Swirl gently until dissolved — don't shake — and label the vial with the concentration and date. Reconstituted solutions are commonly kept refrigerated at 2–8 °C and protected from light. The full step-by-step guide, syringe-scale explainer and BAC vs. sterile water comparison are on the main Peptide Calculator page.
PT-141 calculator FAQ
What concentration does a 10 mg PT-141 vial with 3 mL of bacteriostatic water give?
3.33 mg/mL (3,333 mcg/mL). On a U-100 syringe that is 33.3 mcg per unit, and 10 units hold 0.33 mg.
What concentration does a 10 mg PT-141 vial with 2 mL give?
5.00 mg/mL, or 50.0 mcg per unit on a U-100 syringe.
How many U-100 units contain 1 mg of PT-141?
It depends on the concentration: units per mg = 100 ÷ concentration in mg/mL. At 3.33 mg/mL (10 mg in 3 mL) 1 mg is in 30.00 units; at 5.00 mg/mL (10 mg in 2 mL) it is in 20.00 units.
How much bacteriostatic water should be added to a PT-141 vial?
There is no single correct volume. The volume comes from your own research protocol; the calculator and chart show the concentration each volume produces. Only add a volume your vial can hold.
Is PT-141 the same as bremelanotide?
Yes. PT-141 is the research code for bremelanotide; the calculator math is the same for either label.
Does this PT-141 calculator provide dosing guidance?
No. It performs concentration and unit-conversion math only. All Biogenesis Labs products are supplied for laboratory research use only and are not for human consumption.
