How many units is 1 mg of PT-141?

It depends entirely on how much water you added. In a 10 mg vial reconstituted with 2 mL, the concentration is 5 mg/mL, so 1 mg is 0.2 mL, which is 20 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 10 units, and with 3 mL it is 30 units.

How much bacteriostatic water for a 10 mg PT-141 vial?

2 mL is the usual choice. It gives 5 mg/mL, which puts the commonly reported range of 0.5 mg to 2 mg between roughly 10 and 40 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.

How many doses are in a 10 mg vial?

Divide 10 by your dose. At 1 mg that is 10 doses.

How many units is 1 mg of PT-141?

In a 10 mg vial with 2 mL of water, 20 units on a U-100 syringe. The licensed 1.75 mg dose is 35 units at that concentration.

How long before does PT-141 need to be taken?

The licensed product is taken at least 45 minutes before. Reports commonly describe one to two hours. The half-life is about 2.7 hours.

PT-141 dosage calculator

PT-141 is dosed as needed rather than daily, usually 0.5 to 2 mg an hour or two beforehand.

Peptulator, peptulator.com. Research use only, not medical advice.

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25 printable pages: dosing cards for the twelve most-used compounds at three water volumes, titration planners, a vial log, and five pages on what to do when it has already gone wrong.

Dose to units at the usual vial and water

Dose	U-100 units	Draw	Doses per vial	Vial lasts
0.5 mg	10 units	0.1 mL	20	20 uses
0.75 mg	15 units	0.15 mL	13	13 uses
1 mg	20 units	0.2 mL	10	10 uses
1.5 mg	30 units	0.3 mL	6	6 uses
1.75 mg	35 units	0.35 mL	5	5 uses
2 mg	40 units	0.4 mL	5	5 uses

10 mg vial in 2 mL of bacteriostatic water (5 mg/mL), U-100 insulin syringe, as needed.

About PT-141

PT-141 is bremelanotide, a melanocortin receptor agonist. It is a licensed medicine (Vyleesi) at 1.75 mg by subcutaneous autoinjector for hypoactive sexual desire disorder in premenopausal women, with a limit of one dose in 24 hours and eight a month. Research vials of 10 mg are sold outside that licence, for both sexes.

A 10 mg vial with 2 mL of water is 5 mg/mL, so 1 mg is 0.2 mL, or 20 units, and the licensed 1.75 mg is 35 units. Nausea is the most reported side effect and scales with dose, which is why most people who use it start at the low end. It raises blood pressure transiently; the licence excludes people with uncontrolled hypertension.

The same 10 mg vial at other water volumes

If the draw is awkward to read, change the water, not the dose. The dose stays the same; only the mark moves.

Vial	BAC water	Concentration	Draw	U-100 units	Doses/vial
10 mg	1 mL	10 mg/mL	0.1 mL	10 units	10
10 mg	2 mL	5 mg/mL	0.2 mL	20 units	10
10 mg	3 mL	3.33 mg/mL	0.3 mL	30 units	10

All rows above assume a 1 mg dose and a standard U-100 insulin syringe, where 100 units = 1 mL.

How long it lasts in the body

The half-life of PT-141 is about 2.7 hours. That is the time for the amount in your blood to halve, so after one half-life you are at 50 percent of the peak, after two you are at 25 percent, and after four you are at roughly 6 percent. It is cleared the same day, so there is no build-up between uses and nothing left over by the next one; the effect window is a few hours after each dose.

Common questions

How many units is 1 mg of PT-141?: It depends entirely on how much water you added. In a 10 mg vial reconstituted with 2 mL, the concentration is 5 mg/mL, so 1 mg is 0.2 mL, which is 20 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 10 units, and with 3 mL it is 30 units.
How much bacteriostatic water for a 10 mg PT-141 vial?: 2 mL is the usual choice. It gives 5 mg/mL, which puts the commonly reported range of 0.5 mg to 2 mg between roughly 10 and 40 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.
How many doses are in a 10 mg vial?: Divide 10 by your dose. At 1 mg that is 10 doses.
How many units is 1 mg of PT-141?: In a 10 mg vial with 2 mL of water, 20 units on a U-100 syringe. The licensed 1.75 mg dose is 35 units at that concentration.
How long before does PT-141 need to be taken?: The licensed product is taken at least 45 minutes before. Reports commonly describe one to two hours. The half-life is about 2.7 hours.

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The maths is openThe formula is on every page and in the methodology. The code is one file with an automated test suite, run before each deploy.

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ReviewedDose ranges and half-lives checked 3 September 2026.

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Where to buyWhat to check before you order Vendor scorecardRanked vendors, at Peptide Bureau Build a full protocolThe stack builder at Peptide Bureau, about two minutes

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Before you use these numbers This is a unit-conversion tool. It turns a vial strength and a water volume into a concentration, a draw volume and a syringe mark. It does not tell you what to take, whether to take it, or whether a compound is safe for you. Most compounds listed are sold for laboratory research and are not approved for human use. Nothing here is medical advice. Dosing decisions belong with a licensed clinician who knows your history. Always check the strength printed on your own vial rather than trusting a preset.