To work out the units for PT-141 (Bremelanotide) you need two numbers: how many milligrams (mg) are in your vial, and how many millilitres (mL) of liquid you added to mix it. From those, the math gives you the concentration and then the amount to measure. This page is educational only — it is not medical advice, and it does not recommend a dose. Always follow your prescriber and pharmacist.
PT-141, or bremelanotide, is a melanocortin receptor agonist studied for sexual arousal. It acts through the nervous system rather than on blood flow, which is what distinguishes it from the more familiar erectile-dysfunction medicines.
This one needs care, because two different things share a name. Bremelanotide IS FDA-approved — as Vyleesi, approved in June 2019 for acquired, generalized hypoactive sexual desire disorder in premenopausal women. But Vyleesi is a sealed, prefilled autoinjector delivering a fixed 1.75 mg dose, taken at least 45 minutes before activity. A research vial of PT-141 powder that you mix yourself is not that approved product and does not carry its approval, its manufacturing controls, or its label.
PT-141 (Bremelanotide) vials are commonly reconstituted with bacteriostatic water — sterile water with a preservative that lets a multi-dose vial be entered more than once. The choice of liquid does not change the units-to-draw math: the calculation depends only on the milligrams in the vial and the millilitres you add. Which diluent to use is a question for your pharmacist; the arithmetic below is the same either way.
The two-step formula is:
(On a standard U-100 insulin syringe, 100 units = 1 mL. Remember that 1 mg = 1000 mcg.)
Example 1 — example only; your vial may differ, confirm with your pharmacist. Suppose a vial holds 10 mg and you add 2 mL of water. Concentration = 10 × 1000 ÷ 2 = 5000 mcg per mL. If someone were measuring a 1000 mcg amount purely as arithmetic: 1000 ÷ 5000 × 100 = 20 units. This is a neutral illustration of the math, not a recommended dose.
Example 2 — example only; your vial may differ, confirm with your pharmacist. Take the same 10 mg vial but add only 1 mL. Concentration = 10000 mcg per mL, and the same 1000 mcg becomes 1000 ÷ 10000 × 100 = 10 units. Same powder, same amount — 20 units one way and 10 the other, purely because of the water. That is why you always run your own vial’s numbers.
You will see various PT-141 (Bremelanotide) amounts quoted online and in supplier literature. They are mentioned here strictly as educational context — they are not a recommendation, and what is appropriate for you is a decision for your physician. Do not take a number from a calculator or a forum. Use this tool only to check the mixing arithmetic for the vial in front of you.
This is a mixing-math and concentration tool, not a dosing tool, and it cannot tell you whether a compound, an amount, or a product is appropriate or safe for you. A few honest reminders:
Pepathary is a free, offline, educational tracker. It does not sell, source, or recommend any product, compound, or dose.
There is no single answer — it depends on the concentration of your mixed vial. For example only: a 10 mg vial mixed with 2 mL of water is 5000 mcg per mL, which would make 1000 mcg 20 units; the same vial mixed with 1 mL is 10000 mcg per mL, which would make the same 1000 mcg 10 units. Run your own vial's mg and water through the formula, and confirm any amount with your physician — this is mixing math, not a dose recommendation.
That is a question for your pharmacist and for the instructions supplied with your vial — this page does not tell you how much to add. What it does show is how to turn whatever amount you added into a usable number. More liquid makes a more dilute mix (a larger volume per amount), less liquid makes a more concentrated one.
Partly, and the distinction matters. Bremelanotide is FDA-approved as Vyleesi, a sealed prefilled autoinjector with a fixed 1.75 mg dose, approved in 2019 for hypoactive sexual desire disorder in premenopausal women. A research vial of PT-141 powder is not that product and does not carry its approval or its manufacturing controls.
No. The calculation depends only on the milligrams in the vial and the millilitres of liquid you add. Whether that liquid is bacteriostatic water, sterile saline or dilute acetic acid, the arithmetic is identical. Which diluent to use is a pharmacist question about solubility and sterility, not a math question.
No. This is a reconstitution (mixing-math) tool that converts your vial mg and liquid mL into a concentration and a measurable amount. It does not recommend, select, or endorse a dose, and the example numbers are neutral illustrations of arithmetic only. Always follow your physician's and pharmacist's instructions.