Bremelanotide (Vyleesi)
FDA-approved (2019) melanocortin agonist for premenopausal hypoactive sexual desire disorder. Same molecule as PT-141.
Sexual HealthReconstitution calculatorShowHide
The total peptide in the vial — the mg number on the label (e.g. 5 mg). This is your whole supply, not one dose.
The sterile water you add to dissolve the powder (this is called reconstituting). More water makes small doses easier to measure.
How much you take in one injection. 1 mg = 1000 mcg.
Draw to 10 units
0.10 mL on a U-100 insulin syringe
A starting reference, not medical advice — see how we source this.
- Half-life
- ~2 h
- Route
- SubQ
- Storage
- Refrigerated 2-8°C; use within ~30 days (~30 days)
- Citations
- 1 referenced
US regulatory status
FDA-approved in 2019 (marketed as Vyleesi) in the context of premenopausal hypoactive sexual desire disorder.
What is Bremelanotide (Vyleesi)?
Bremelanotide (marketed as Vyleesi) is a non-selective melanocortin receptor agonist and the same molecule as PT-141. It is studied for its action on central nervous system pathways associated with sexual desire.
How Bremelanotide (Vyleesi) works
Non-selective melanocortin receptor agonist that activates central nervous system pathways involved in sexual desire.
What the research says
The published literature includes two randomized Phase 3 trials that examined bremelanotide in the setting of hypoactive sexual desire disorder. This work investigated how the compound engages melanocortin receptor pathways in the central nervous system. Research has characterized it as a non-selective melanocortin receptor agonist rather than a peripherally acting agent.
Evidence limitations
As with any single research program, the scope of what has been examined is defined by these controlled trials.
Safety & use boundary
Outside of its specific approved context, bremelanotide is handled as a research compound and is not intended for general human use. This information is educational and is not medical advice.
How to reconstitute Bremelanotide (Vyleesi)
New to this? Here's the whole process, start to finish. Educational only — not medical advice.
What you'll need
- The Bremelanotide (Vyleesi) vial — a small glass vial of white, freeze-dried powder
- Bacteriostatic water — the liquid you mix in (not plain sterile or tap water)
- U-100 insulin syringes — the small syringes marked in units
- Alcohol swabs to wipe the vial tops before you touch them with a needle
- A spot in the fridge to keep it once it's mixed
Step by step
Wipe everything down
Swab the rubber top of both the peptide vial and the bacteriostatic water with an alcohol wipe. Clean tops are what keep the mixed solution good for weeks instead of days.
Draw the water
Use the calculator above to see how much bacteriostatic water to add for your vial size. Pull exactly that amount out of the water vial with a syringe.
Add it slowly
Push the needle into the peptide vial and let the water run gently down the inside glass wall — don't blast it straight onto the powder.
Let it dissolve
Swirl the vial gently or just let it sit. The powder goes into solution on its own in a minute or two. Never shake it hard.
Read your draw
Enter your vial size, the water you added, and your dose in the calculator. It shows the exact units to pull into your syringe — you never do the math yourself.
Store it cold
Cap it and keep it in the fridge. Bremelanotide (Vyleesi) stays good for about 30 days once it's mixed.
Reading your dose
The calculator gives you a number like “Draw to 20 units.” Units are just the numbered marks on a U-100 insulin syringe (100 units fill 1 mL). “20 units” means pull the plunger back to the 20 mark. You don't convert milligrams to micrograms in your head — that's the whole point of the calculator. If you're brand new to injecting, learn proper technique and site rotation from a qualified clinician or nurse before your first dose; this page covers the mixing and measuring, not the injection itself.
Storing it
Before mixing: Refrigerated Once reconstituted: Refrigerated 2-8°C; use within ~30 days (about 30 days). Don't freeze a reconstituted vial.
Common first-timer mistakes
Shaking the vial to mix it
Swirl it gently or just let it sit. Shaking can damage delicate peptides — you want the powder to dissolve, not foam.
Using tap water or plain sterile water
Use bacteriostatic water. Plain sterile water has no preservative, so a mixed vial spoils in a day or two instead of lasting weeks.
Leaving a mixed vial on the counter
Keep reconstituted vials in the fridge. Heat and light break the peptide down faster.
Eyeballing the dose instead of measuring
Use the calculator and draw to the exact unit mark on the syringe. Guessing a tiny volume is where most measuring errors happen.
Reusing needles
Use a fresh syringe each time. A used needle is duller, hurts more, and is no longer sterile.
Mixing up mg and mcg
1 mg = 1000 mcg. The calculator keeps them straight so you don't have to — just enter your dose in the unit it asks for.
Words you'll see
- Reconstitution
- Mixing a freeze-dried peptide powder with liquid (bacteriostatic water) so it can be drawn into a syringe.
- Bacteriostatic water
- Sterile water with a tiny amount of benzyl alcohol that stops bacteria growing, so a mixed vial keeps for weeks. Not the same as plain sterile water.
- U-100 insulin syringe
- A small syringe marked in “units,” where 100 units = 1 mL. Peptide draws are measured in these units.
- Subcutaneous (SubQ)
- An injection into the fatty layer just under the skin, rather than into muscle or a vein.
- mcg vs mg
- 1 mg = 1000 mcg. Doses are often written in micrograms (mcg); the calculator handles the conversion for you.
- Lyophilized
- Freeze-dried. The powder in the vial is the peptide with its water removed so it stays stable on the shelf.
- Half-life
- Roughly how long it takes your body to clear half of a dose — a rough sense of how long it stays active.
Common questions
What is Bremelanotide (Vyleesi)?
FDA-approved (2019) melanocortin agonist for premenopausal hypoactive sexual desire disorder. Same molecule as PT-141. Non-selective melanocortin receptor agonist that activates central nervous system pathways involved in sexual desire.
How is Bremelanotide (Vyleesi) reconstituted?
Bremelanotide (Vyleesi) ships as a lyophilised powder and is reconstituted with bacteriostatic water before use, then drawn on an insulin syringe. Use the calculator above to see the exact units to draw for your vial size and dose. This is a reference tool, not medical advice.
What is the half-life of Bremelanotide (Vyleesi)?
Research reports an approximate half-life of 2 hours for Bremelanotide (Vyleesi). Half-life informs how frequently a compound is studied; it is not a dosing instruction.
How should Bremelanotide (Vyleesi) be stored?
Refrigerated Once reconstituted: Refrigerated 2-8°C; use within ~30 days (about 30 days). This is general storage information, not medical advice.
Keep your protocol, doses, and vials in one place.
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