PT-141 (Bremelanotide)

PT-141 (Bremelanotide) is a synthetic peptide and approved drug from the melanocortin peptide family. It is an analog of the body's own α-melanocyte-stimulating hormone (α-MSH). In the US it is marketed as Vyleesi (Palatin/AMAG) as a subcutaneous injection approved by the FDA in June 2019 (NDA 210557) for hypoactive sexual desire disorder (HSDD) in premenopausal women. There is no EMA approval in the EU.

How does Bremelanotide work?

PT-141 is a non-selective agonist at melanocortin receptors MC1, MC3, MC4, and MC5, with its main effect taking place centrally in the hypothalamus. Through the MC3/MC4 axis it modulates sexual desire and arousal - in contrast to PDE5 inhibitors like sildenafil, which act peripherally on blood flow.

What is the evidence?

FDA approval is based on two identical phase III trials (RECONNECT) in 1247 premenopausal women over 24 weeks. The treatment produced statistically significant but clinically modest improvements in desire and distress scores. Independent re-analyses - notably Spielmans (2021) and Mintzes (2021) - question the clinical meaningfulness of the effect sizes and critically review the regulatory precedent.

What side effects are documented?

• Transient increase in blood pressure (max +6 mmHg systolic, +3 mmHg diastolic) and decrease in heart rate (up to -5 bpm), peaking 2-4 hours post-injection and usually resolving within 12 hours.
• Common: nausea, flushing, and headache.
• Contraindicated in uncontrolled hypertension and known cardiovascular disease.
• Use in severe hepatic impairment is not recommended (data lacking).

How is PT-141 used?

The Vyleesi label specifies 1.75 mg subcutaneously "as needed" about 45 minutes before sexual activity, maximum once within 24 hours. The half-life per FDA review is approximately 2.7 hours. This is not a dosing instruction - always discuss indication, suitability, and safety with your prescribing physician.

PT-141 vs. Melanotan II - what's the difference?

Bremelanotide comes from the same pharmacological family as Melanotan II - both are synthetic α-MSH analogs. Unlike Melanotan II, PT-141 is an approved drug with a defined purity profile and a reviewed safety dataset. Unapproved "PT-141" from research-chemical sources is no substitute for the FDA-reviewed Vyleesi - quality, dosing accuracy, and sterility are then unknown.

Frequently asked questions

Does PT-141 work in men?

FDA approval is explicitly limited to HSDD in premenopausal women. Studies in men have been conducted, but the drug is not approved for male sexual dysfunction.

How is PT-141 different from sildenafil?

Sildenafil (a PDE5 inhibitor) acts peripherally on blood flow. Bremelanotide acts centrally via hypothalamic melanocortin receptors on desire and arousal - not primarily on erection mechanics.

Is PT-141 legally available in the EU?

No. There is no EMA approval. In Germany and the EU, pharmaceutical-grade PT-141 falls under medicines law and is not legally available as a freely sold "peptide." Authorities warn of the same risks as with illegal Melanotan products.

This entry is for informational purposes only and does not constitute medical advice or a recommendation.