PT-141 calculator
A melanocortin receptor agonist approved for hypoactive sexual desire disorder in premenopausal women.
Also known as: Bremelanotide, Vyleesi
FDA status FDA-approved as Vyleesi (bremelanotide) for acquired, generalized hypoactive sexual desire disorder in premenopausal women. Research-grade PT-141 sold outside that product is not FDA-approved.
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What PT-141 is
PT-141, generically bremelanotide, is a melanocortin receptor agonist approved as Vyleesi for acquired, generalized hypoactive sexual desire disorder in premenopausal women. Unlike PDE5 inhibitors such as sildenafil, it acts on the nervous system rather than on blood flow.
Research depth: 5/5 Complete phase 3 program (RECONNECT) supporting FDA approval, plus earlier trials in other populations. Human trials: Phase 3 trials. This measures how much has been studied — counting animal and laboratory work — not whether it works for you.
How PT-141 works
It activates melanocortin receptors — chiefly MC4R — in the central nervous system, influencing the dopamine pathways that govern sexual desire. Because the mechanism is neurological rather than vascular, it is taken in anticipation of activity rather than working on demand through circulation.
PT-141 side effects
Commonly reported
- Nausea, sometimes significant, especially with a first dose
- Flushing
- Headache
- Injection-site reactions
- Temporary darkening of the skin or gums with repeated use
Serious — seek medical care
- Transient increases in blood pressure and decreases in heart rate — not recommended with uncontrolled hypertension or cardiovascular disease
- Focal hyperpigmentation that may not fully resolve
- Severe nausea requiring anti-nausea treatment
This list is not exhaustive. Report anything unexpected to the clinician who prescribed it. If you have severe abdominal pain, trouble breathing, or signs of an allergic reaction, seek care the same day. See also our guide to peptide side effects by class.
A worked example
A 10 mg vial reconstituted with 2 mL of bacteriostatic water gives 5 mg/mL. A 1000 mcg dose is then 0.2 mL — about 20 units on a 100-unit insulin syringe, giving roughly 10 doses per vial before accounting for residual volume left in the vial and syringe.
Prefer paper? Download the printable PT-141 dosing chart (PDF) — every vial size and water volume in syringe units, with the same review byline as this page. All charts →
Commonly cited dose range
Figures circulating for PT-141 run from 500 mcg to 1750 mcg. The approved product is a fixed-dose autoinjector. Figures here reflect commonly discussed reconstituted vial use.
Read this as reference information, not instruction. These numbers describe what is commonly discussed, not what is right for any individual. Dose, frequency, and whether to use PT-141 at all are decisions for a licensed clinician who knows your history.
Common questions
How many units is 1 mg of PT-141?
With a 10 mg vial in 2 mL of bacteriostatic water (5 mg/mL), 1 mg is 0.2 mL — 20 units on a 100-unit insulin syringe.
Is PT-141 the same as Vyleesi?
Vyleesi is the FDA-approved bremelanotide product, supplied as a fixed-dose autoinjector. Loose PT-141 vials sold as research material are not the approved product and are not reviewed by FDA.