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PT-141 is the research name for bremelanotide. The FDA approved it in 2019 as Vyleesi, a prefilled autoinjector that delivers 1.75 mg in 0.3 mL, for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD). The label says it isn't indicated for postmenopausal women or men, or to enhance sexual performance (Vyleesi label).
If you have Vyleesi, follow the instructions that came with the autoinjector. There's nothing to mix and no units to count.
This calculator is for bremelanotide powder in a vial, usually from a compounding pharmacy. Compounded versions aren't FDA-approved, which means the FDA hasn't reviewed that specific product for safety or quality. Get it only through a licensed prescriber and pharmacy, never from sellers marketing "research use only" vials.
The Vyleesi label lists nausea as the most common side effect, reported by 40% of people in trials, and says it shouldn't be used by anyone with uncontrolled high blood pressure or known cardiovascular disease. It also says not to use more than one dose in 24 hours. Those warnings come from the approved product, and your prescriber should go over how they apply to you.
Step 1: Enter your vial size in mg. Use the amount on the label, such as 10 mg.
Step 2: Enter the bacteriostatic water you added. If your vial arrived already mixed, use the label concentration: a vial labelled 5 mg/mL is the same as 10 mg in 2 mL.
Step 3: Choose your syringe. At the default concentration, the presets come out between 10 and 35 units, so a 0.5 mL (50 unit) syringe fits them all.
Step 4: Enter your prescribed amount in mg. The presets are shortcuts, not recommendations. Always use the number your prescriber gave you.
With the defaults shown, a 10 mg vial mixed with 2 mL is 5 mg/mL, so 1 mg is 0.2 mL, or 20 units. Mix the same vial with 1 mL and 1 mg is 10 units.
100 units on a U-100 syringe is always 1 mL. How much bremelanotide sits in those units depends on your concentration.
2.5 mg/mL is a 5 mg vial in 2 mL, 5 mg/mL is a 10 mg vial in 2 mL, and 10 mg/mL is a 10 mg vial in 1 mL. The formula is: units = amount in mg ÷ concentration in mg/mL × 100.
Our peptide syringe units guide explains how to read each syringe size. The general peptide calculator covers other peptides, and PeptideKit can keep a private log of each dose and any side effects to share with your prescriber.
Divide the vial's mg by the mL of water added to get mg/mL. Divide your prescribed amount by that concentration to get mL, then multiply by 100 for U-100 syringe units.
At 5 mg/mL (10 mg in 2 mL), 1 mg is 20 units. At 10 mg/mL, it's 10 units. At 2.5 mg/mL, it's 40 units. This is a conversion example, not a suggested dose.
10 units is 0.1 mL. At 2.5 mg/mL that's 0.25 mg, at 5 mg/mL it's 0.5 mg, and at 10 mg/mL it's 1 mg.
The active ingredient is the same: bremelanotide. Vyleesi is the FDA-approved product, made and tested by its manufacturer and sold as a ready-to-use autoinjector. Compounded or online "PT-141" vials are not Vyleesi and haven't been through the same review.
No. The autoinjector delivers a fixed dose and has no syringe markings to read. Follow its instructions for use.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.
PT-141 Dosage Calculator
Enter your PT-141 vial size, how much bacteriostatic water was added, and the amount your prescriber gave you in mg. The calculator shows how many units to draw on a U-100 insulin syringe.
Peptide Amount in Vial
BAC Water
Syringe
Target Dose
Use the dose on your prescription. Presets are shortcuts, not recommendations.
Unit Rounding
Round the result to a whole or half unit mark you can read on your syringe.
Peptide Amount (Total in Vial)
Desired Concentration
When You Don't Need This Calculator
PT-141 is the research name for bremelanotide. The FDA approved it in 2019 as Vyleesi, a prefilled autoinjector that delivers 1.75 mg in 0.3 mL, for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD). The label says it isn't indicated for postmenopausal women or men, or to enhance sexual performance (Vyleesi label).
If you have Vyleesi, follow the instructions that came with the autoinjector. There's nothing to mix and no units to count.
This calculator is for bremelanotide powder in a vial, usually from a compounding pharmacy. Compounded versions aren't FDA-approved, which means the FDA hasn't reviewed that specific product for safety or quality. Get it only through a licensed prescriber and pharmacy, never from sellers marketing "research use only" vials.
The Vyleesi label lists nausea as the most common side effect, reported by 40% of people in trials, and says it shouldn't be used by anyone with uncontrolled high blood pressure or known cardiovascular disease. It also says not to use more than one dose in 24 hours. Those warnings come from the approved product, and your prescriber should go over how they apply to you.
How to Use the PT-141 Dosage Calculator
Step 1: Enter your vial size in mg. Use the amount on the label, such as 10 mg.
Step 2: Enter the bacteriostatic water you added. If your vial arrived already mixed, use the label concentration: a vial labelled 5 mg/mL is the same as 10 mg in 2 mL.
Step 3: Choose your syringe. At the default concentration, the presets come out between 10 and 35 units, so a 0.5 mL (50 unit) syringe fits them all.
Step 4: Enter your prescribed amount in mg. The presets are shortcuts, not recommendations. Always use the number your prescriber gave you.
With the defaults shown, a 10 mg vial mixed with 2 mL is 5 mg/mL, so 1 mg is 0.2 mL, or 20 units. Mix the same vial with 1 mL and 1 mg is 10 units.
PT-141 Units to mg Conversion Table
100 units on a U-100 syringe is always 1 mL. How much bremelanotide sits in those units depends on your concentration.
| Syringe units | Volume | At 2.5 mg/mL | At 5 mg/mL | At 10 mg/mL |
|---|---|---|---|---|
| 5 units | 0.05 mL | 0.125 mg | 0.25 mg | 0.5 mg |
| 10 units | 0.1 mL | 0.25 mg | 0.5 mg | 1 mg |
| 20 units | 0.2 mL | 0.5 mg | 1 mg | 2 mg |
| 30 units | 0.3 mL | 0.75 mg | 1.5 mg | 3 mg |
| 35 units | 0.35 mL | 0.875 mg | 1.75 mg | 3.5 mg |
| 40 units | 0.4 mL | 1 mg | 2 mg | 4 mg |
| 50 units | 0.5 mL | 1.25 mg | 2.5 mg | 5 mg |
Our peptide syringe units guide explains how to read each syringe size. The general peptide calculator covers other peptides, and PeptideKit can keep a private log of each dose and any side effects to share with your prescriber.
Frequently Asked Questions
How do I calculate PT-141 units?
Divide the vial's mg by the mL of water added to get mg/mL. Divide your prescribed amount by that concentration to get mL, then multiply by 100 for U-100 syringe units.
How many units is 1 mg of PT-141?
At 5 mg/mL (10 mg in 2 mL), 1 mg is 20 units. At 10 mg/mL, it's 10 units. At 2.5 mg/mL, it's 40 units. This is a conversion example, not a suggested dose.
How much PT-141 is in 10 units?
10 units is 0.1 mL. At 2.5 mg/mL that's 0.25 mg, at 5 mg/mL it's 0.5 mg, and at 10 mg/mL it's 1 mg.
Is PT-141 the same as Vyleesi?
The active ingredient is the same: bremelanotide. Vyleesi is the FDA-approved product, made and tested by its manufacturer and sold as a ready-to-use autoinjector. Compounded or online "PT-141" vials are not Vyleesi and haven't been through the same review.
Can I use this calculator for a Vyleesi autoinjector?
No. The autoinjector delivers a fixed dose and has no syringe markings to read. Follow its instructions for use.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.