Libido
PT-141, simplified.
Also called Bremelanotide, Vyleesi
Approved RxA prescription peptide for low sexual desire that works on the brain, not blood flow.
- Size
- 7 amino acids (ring-shaped)
- How it is taken
- Injection as needed
- Status
- FDA-approved for one use
- Available sizes
- Vials: 10 mg
What is it?
PT-141 acts on melanocortin receptors in the brain, which are involved in desire. That is different from drugs like Viagra, which work on blood flow.
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Official prescribing information
Vyleesi is FDA-approved. The official label shows how it was dosed in the trials that led to approval, along with warnings and who should not use it.
Doses on the label are for the approved product under a prescriber’s care. Talk with your doctor before starting anything.
What studies show
- In peopleIn two large trials of premenopausal women with low desire, it modestly improved desire and reduced distress compared with placebo.
What we don’t know yet
- How well it works in men. Studies are small.
Side effects and cautions
- Nausea is common, affecting about 4 in 10 people in trials.
- It can briefly raise blood pressure.
- Repeated use can darken patches of skin.
Is it legal?
FDA-approved for premenopausal women with low sexual desire. Other uses are off-label.
Dosage & schedule evidence
How to read published schedules
An FDA-approved bremelanotide product has indication-specific labeling. This does not validate third-party peptide protocols or other formulations.
| Measurement | Meaning |
|---|---|
| 1 mg | 1,000 mcg (mass) |
| 100 U-100 units | 1 mL (volume, not dose) |
See third-party published protocols ↗ for research context. North Star does not validate these schedules.
Consult your doctor before considering any peptide for personal use. Educational only, not administration guidance.
Common questions
What is PT-141?
A prescription peptide for low sexual desire that works on the brain, not blood flow. PT-141 acts on melanocortin receptors in the brain, which are involved in desire. That is different from drugs like Viagra, which work on blood flow.
What does the research say about PT-141?
In two large trials of premenopausal women with low desire, it modestly improved desire and reduced distress compared with placebo.
Is PT-141 FDA approved?
FDA-approved for premenopausal women with low sexual desire. Other uses are off-label.
What are the side effects of PT-141?
Nausea is common, affecting about 4 in 10 people in trials. It can briefly raise blood pressure. Repeated use can darken patches of skin.
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This page explains published research in plain language. It is not medical advice, a diagnosis, or a recommendation to take anything, and it does not give dosing. Most peptides here are not FDA-approved, and products sold online vary widely in purity. Rules around peptides are changing, so check the current status and talk with a licensed clinician before starting anything. Last reviewed 2026-10-19.