PT-141 (Bremelanotide)

FDA-approved context Sexual Wellness In 1 protocol 3 sources

PT-141, also known as bremelanotide, is a synthetic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It acts as a non-selective agonist of the melanocortin receptors, primarily MC4R, and is FDA-approved for the treatment of generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. Research shows it can also induce erections in men, working through the central nervous system rather than the vascular system.

01Dosing reference

Amount

1.75 mg (FDA approved dose) or 1-2 mg for research

Frequency

As needed, at least 45 minutes before anticipated sexual activity. No more than one dose per 24 hours.

Cycle

No more than 8 doses per month.

Reference figures, not a recommendationThese values reflect amounts described in the literature and vendor documentation this database indexes. Use the reconstitution calculator to convert them into syringe units.

02Mechanism of action

Melanocortin receptor activation

PT-141 binds to and activates melanocortin receptors, primarily MC4R, in the central nervous system.

Central nervous system stimulation

Activation of these receptors in the hypothalamus triggers neural pathways associated with sexual arousal and desire.

Enhanced sexual response

This central activation leads to increased sexual desire in women and can induce erections in men, independent of direct vascular manipulation.

03Human evidence

Bremelanotide significantly increases sexual desire and decreases distress related to low sexual desire in premenopausal women with HSDD.

Demonstrated in large-scale Phase 3 clinical trials (RECONNECT studies) which led to its FDA approval.

PT-141 induces erections in men with erectile dysfunction, including those who do not respond to PDE5 inhibitors.

Observed in early clinical trials in men, though development for male ED was halted due to transient increases in blood pressure.

04Preclinical evidence

Administration of bremelanotide stimulates sexual behavior and arousal in both male and female animal models.

Observed in rodent studies evaluating the behavioral effects of melanocortin receptor agonists.

Activation of MC4R in the brain is directly linked to the initiation of erectile activity and sexual motivation.

Demonstrated in neuropharmacological studies in rats mapping the neural circuits of sexual function.

05What is known vs. unknown

Reasonably established

FDA-approved under the brand name Vyleesi for HSDD in premenopausal women.
Works centrally in the brain via melanocortin receptors, unlike PDE5 inhibitors which work peripherally on blood vessels.
Can cause transient increases in blood pressure and decreases in heart rate.
Common side effects include nausea, flushing, and headache.

Unknowns & limits

Long-term cardiovascular safety with frequent or prolonged use remains a concern and requires further study.
The exact downstream neural pathways following MC4R activation that translate to increased sexual desire are not fully mapped.

06Safety & regulatory context

Regulatory statusPT-141 is FDA-approved (as Vyleesi) for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), administered via subcutaneous injection. It is contraindicated in patients with uncontrolled hypertension or known cardiovascular disease due to its potential to transiently increase blood pressure and decrease heart rate. The most common side effect is nausea, which can be severe enough to require antiemetics. Other side effects include flushing, injection site reactions, headache, and focal hyperpigmentation.

07Compared with Melanotan II (MT-II)

PT-141 (Bremelanotide) vs. Melanotan II (MT-II)

Key difference

PT-141 is a metabolite of MT-II that isolates the sexual arousal effects while minimizing the tanning (melanogenesis) effects, though some overlap remains.

When researchers discuss each

MT-II is primarily discussed for tanning and photoprotection with secondary sexual effects, whereas PT-141 is specifically researched and approved for sexual dysfunction and arousal.

08Appears in protocols

⚖️ Hormonal Optimization Protocol

2 mg as needed (max 2x/week)As needed (max 2x/week)

09Glossary

HSDD

Hypoactive Sexual Desire Disorder, characterized by a persistent lack of sexual fantasies and desire for sexual activity that causes marked distress.

Melanocortin Receptors

A family of receptors in the body; the MC4R subtype is particularly involved in regulating sexual function and appetite.

Agonist

A substance that binds to a receptor and activates it to produce a biological response.

10Knowledge check

Q1How does PT-141 differ from PDE5 inhibitors like sildenafil (Viagra) in its mechanism of action?

Q2What is the most common side effect associated with PT-141 administration?

Q3Which interpretation about PT-141's cardiovascular safety is best supported by the dossier?

Q4According to the dossier's comparison with Melanotan II (MT-II), which statement best captures the key difference?

Q5Which regulatory or safety context about PT-141 is directly supported by the dossier?

11Sources

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Research and educational use onlyNothing on this site is medical advice, a prescription, or a recommendation for human use. Compounds documented here are research chemicals. Consult a qualified clinician before making any health decision.