PT-141
Other
In short
- Also known as bremelanotide. FDA-approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women.
- A melanocortin receptor agonist — it acts centrally in the brain rather than on vascular tissue like PDE5 inhibitors.
- Derived from Melanotan II, but developed and approved as a distinct medicine.
- Nausea is the dominant side effect, affecting roughly 40% of participants in trials.
- Transient blood pressure increases are documented; contraindicated in uncontrolled hypertension and cardiovascular disease.
Structure
How it works
Bremelanotide is a cyclic heptapeptide agonist at melanocortin receptors, with activity primarily at MC4R and MC1R. MC4R signalling in the hypothalamus is involved in sexual desire and arousal pathways.
This is a fundamentally different mechanism from sildenafil and related drugs, which act peripherally on smooth muscle and blood flow. PT-141 acts on the central drive rather than the plumbing, which is why it was pursued for desire disorders rather than erectile mechanics.
What the research shows
The RECONNECT phase 3 programme in premenopausal women with HSDD showed statistically significant improvements in desire and reductions in distress versus placebo. Effect sizes were modest and the clinical meaningfulness of the change has been debated in the literature.
Earlier development for erectile dysfunction, including intranasal formulations, was discontinued after blood pressure increases were observed.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — approved label (Vyleesi), premenopausal women with HSDD | 1.75 mg as needed, at least 45 minutes before anticipated activity; maximum one dose per 24 hours and eight per month | subcutaneous autoinjector | FDA label |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported, both sexes | 0.5–2 mg as needed | subcutaneous |
The label limits of one dose per 24 hours and eight per month exist because of the blood pressure effect and were part of the approved safety profile. Use in men is outside the approved indication and outside the trial evidence.
Handling and storage
The approved product is a single-use autoinjector into the thigh or abdomen, taken at least 45 minutes before anticipated sexual activity.
Research-market vials require reconstitution and manual measurement. The effect is commonly reported as slow in onset and long in duration relative to PDE5 inhibitors.
Side effects
Nausea is by far the most common, reported by roughly 40% of trial participants and occasionally severe enough to cause discontinuation. Flushing, injection-site reactions, and headache are also common.
Transient increases in blood pressure and decreases in heart rate occur after each dose; this is why it is contraindicated in uncontrolled hypertension and known cardiovascular disease.
Focal hyperpigmentation can occur with repeated use, reflecting MC1R activity — more likely with more frequent dosing than the label allows.
Combinations
Combining with PDE5 inhibitors was specifically cautioned during development because both can lower blood pressure, and the interaction was a factor in the discontinuation of the erectile dysfunction programme.
Combining with Melanotan II duplicates melanocortin agonism and compounds both nausea and pigmentation effects.
Research status
Two phase 3 randomised placebo-controlled trials (RECONNECT) supported the 2019 approval. Earlier intranasal development was halted over blood pressure signals. Ongoing interest exists in melanocortin agonism more broadly.
Legal status
FDA-approved and prescription-only in the US as Vyleesi for a specific indication in premenopausal women. Research-market PT-141 sold for other uses is unapproved and unregulated.
WADA status
Not specifically named on the WADA Prohibited List as of this review date. Verify against the live list before competition.
Conclusion
PT-141 is an approved medicine with a genuine mechanism and a genuine side-effect profile, most of which is nausea. The approval is narrow, and the dosing frequency limits in the label are there for a documented cardiovascular reason rather than caution for its own sake.
If you use it outside that indication, the blood pressure effect is the part worth taking seriously.
Sources
Track your own PT-141 protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.