PT-141.
PT-141, generic name bremelanotide, is a synthetic cyclic heptapeptide that acts as a melanocortin receptor agonist.
PT-141, generic name bremelanotide, is a synthetic cyclic heptapeptide that acts as a melanocortin receptor agonist. PT-141 is fda-approved, and PepCue grades its published evidence B tier (76/100). Also known as bremelanotide · Vyleesi. This is a research reference, not medical or dosing advice.
What it is
PT-141, generic name bremelanotide, is a synthetic cyclic heptapeptide that acts as a melanocortin receptor agonist. It originated from work on the tanning peptide melanotan II (and is closely related to a melanotan-II metabolite, differing chiefly by a hydroxyl rather than an amide group), refined by Palatin Technologies to favor sexual-function effects over skin pigmentation. As the prescription product Vyleesi, it is FDA-approved for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women.
How it works
Bremelanotide is a non-selective agonist of melanocortin receptors with activity at MC1R through MC5R, but its therapeutic effect is attributed primarily to central MC4R (and MC3R) activation in hypothalamic and limbic brain regions that govern sexual motivation and arousal. Unlike PDE5 inhibitors or hormonal agents, it acts on central nervous system pathways rather than directly on vascular or genital tissue, and is thought to modulate dopaminergic signaling in motivation circuits. The FDA label explicitly states that the precise mechanism by which it improves sexual desire and related distress is not fully known. Its activity at peripheral melanocortin receptors (e.g., MC1R) also explains off-target effects such as skin hyperpigmentation and transient cardiovascular changes.
Mechanism pathways
Engaging melanocortin receptors, relevant to pigmentation, sexual arousal, and inflammation.
The melanocortin system consists of five G-protein-coupled receptors, MC1R through MC5R, and their natural ligands derived from proopiomelanocortin, including alpha-melanocyte-stimulating hormone and adrenocorticotropic hormone. Each receptor subtype has a different distribution and a different job, which is why compounds acting on this family produce such varied effects depending on which receptors they touch. MC1R sits on epidermal melanocytes. Activating it raises cyclic AMP and shifts melanin synthesis toward eumelanin, the darker and more photoprotective pigment, independent of ultraviolet exposure. MC3R and MC4R are concentrated in the hypothalamus and limbic regions, where they participate in circuits governing appetite, energy balance, and sexual motivation. MC4R activation in particular is the accepted basis for centrally acting effects on arousal, which operate on motivation pathways rather than on vascular or genital tissue. MC5R is associated with exocrine gland function. Several melanocortin ligands also have anti-inflammatory activity, and this branch is pursued separately. Compounds in this group differ mainly by selectivity, and this is the distinction that determines both intended effect and side effect. A highly MC1R-selective analog is used to increase photoprotective pigmentation and is designed to avoid central receptors. Non-selective agonists bind across most of the family, which is why they produce pigmentation, appetite change, nausea, and arousal effects together rather than separately. A related tripeptide corresponding to the carboxy-terminal fragment of alpha-melanocyte-stimulating hormone retains anti-inflammatory activity but appears to work largely without classical melanocortin receptor engagement, entering cells through a peptide transporter instead. All of these analogs incorporate amino-acid substitutions that resist enzymatic breakdown, since the native hormones are short-lived. Clinical standing varies sharply within the group. Two members are approved medicines in at least some jurisdictions for narrowly defined indications, meaning their receptor mechanisms have been demonstrated in humans. Others in the group have never been approved anywhere and are sold as unregulated research chemicals. Non-selective melanocortin agonism in particular carries documented concerns including nausea, blood pressure effects, and changes to moles and pigmented lesions, and using pigmentation-inducing compounds without dermatological monitoring is widely cautioned against. Receptor pharmacology being well understood does not make an unapproved compound safe. The selectivity point is worth restating, because it is the single most useful thing to know about this family: the difference between a compound that touches one melanocortin receptor and one that touches all five is the difference between a narrow effect and a diffuse one.
The evidence
The strongest human evidence comes from the two identical phase 3 RECONNECT trials (Kingsberg et al., Obstetrics & Gynecology, 2019), randomized, double-blind, placebo-controlled studies in premenopausal women with HSDD that used co-primary endpoints of change in the FSFI desire domain and the FSDS-DAO Item 13 distress score; both showed statistically significant but modest improvements over placebo (integrated desire change ~0.35, distress change ~-0.33, p<0.001), with an open-label extension reporting longer-term safety (Simon et al., Obstet Gynecol 2019). Independent re-analyses (e.g., Spielmans, Journal of Sex Research 2021) argue the effect sizes are small and of uncertain clinical meaningfulness, and roughly 40% of trial participants discontinued. For male sexual dysfunction and other proposed uses, human data are far thinner: earlier intranasal bremelanotide erectile-dysfunction programs were halted partly over blood-pressure concerns, and claims about libido enhancement in men or in postmenopausal women rest largely on small, older, or preclinical studies rather than robust randomized trials. There is no approved or well-evidenced use outside premenopausal-female HSDD.
The evidence, in brief
Bremelanotide is a melanocortin-receptor agonist that is FDA-approved (Vyleesi, 2019) for acquired, generalized hypoactive sexual desire disorder in premenopausal women, supported by the RECONNECT phase-3 trials. Approved for a specific indication; nausea and transient blood-pressure effects are documented.
- Kingsberg SA et al.: Bremelanotide for Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials (RECONNECT)Obstet Gynecol, 2019 (PMID 31599840)
- Vyleesi (bremelanotide): FDA prescribing informationFDA / DailyMed
Evidence maturity
An evidence-only reading: approval status, human vs preclinical data, mechanism and safety. Popularity never raises it. Research file #052
Meaningful human evidence; not yet definitive.
FDA-approved for a specific indication: the strongest lane.
Claim receipts
Popular claims about PT-141, checked against the state of the evidence. The verdict describes evidence maturity, never an invented study result.
Bremelanotide (Vyleesi) is FDA-approved for HSDD in premenopausal women, with trial support.
Effect varies; approval is for a specific population and indication.
Safety profile
The most common adverse effects in trials were nausea (around 40%), flushing, injection-site reactions, and headache; nausea was a frequent reason for discontinuation. Bremelanotide transiently raises blood pressure (peak systolic increase of about 6 mm Hg) and lowers heart rate for several hours after each dose, and the FDA label contraindicates it in people with uncontrolled hypertension or known cardiovascular disease and advises against use in those at high cardiovascular risk. Focal hyperpigmentation of the face, gingiva, and breasts occurred in about 1% of treated patients and becomes more likely with more frequent dosing, and may not fully resolve. Safety beyond the studied population (men, postmenopausal women, and people using non-pharmaceutical "research" peptide products of unverified purity) is not established, and gray-market injectable PT-141 carries additional risks of contamination and inaccurate content.
Compound notes
- PT-141 (bremelanotide) is a melanocortin-receptor agonist that acts centrally (on MC4R pathways in the brain) on sexual-desire signaling.
- It is FDA-approved (brand Vyleesi) for hypoactive sexual desire disorder (HSDD) in premenopausal women, with trial support.
- Its central mechanism is different from PDE5 inhibitors, which act on blood flow.
PT-141 works centrally on desire pathways; sildenafil-type drugs work peripherally on vascular blood flow. Different mechanisms, different intended effects.
- Approved for a specific population and indication; effect varies and it is not a universal libido fix.
- Transient blood-pressure rise and nausea are documented; see the FDA label.
Regulatory status
Bremelanotide was FDA-approved in June 2019 as Vyleesi (subcutaneous injection) for acquired, generalized HSDD in premenopausal women, and is considered a first-in-class melanocortin-receptor agonist for this indication. It is not approved for men, postmenopausal women, erectile dysfunction, or general libido enhancement; PT-141 sold as a "research peptide" outside this approved product is investigational/research-use and not an approved therapy.
Approved by the FDA for at least one indication.
By the numbers
- 01Generic name bremelanotide; brand Vyleesi; a synthetic cyclic heptapeptide derived from melanotan II lineage
- 02First-in-class melanocortin receptor agonist FDA-approved (June 2019) for premenopausal HSDD
- 03Acts centrally via MC4R/MC3R, not directly on genital vasculature like PDE5 inhibitors
- 04RECONNECT phase 3 trials showed statistically significant but modest improvements in desire and distress vs placebo
- 05Contraindicated in uncontrolled hypertension or known cardiovascular disease due to transient blood-pressure increase
- 06Focal hyperpigmentation (~1%) and nausea (~40%) are notable adverse effects
PT-141: research formats
Choose the format you are researching to see route-specific notes.
Vyleesi is an FDA-approved auto-injector; research use from 10 mg vials also exists.
PT-141 (bremelanotide) is FDA-approved as Vyleesi (1.75 mg/0.3 mL auto-injector) for hypoactive sexual desire disorder in premenopausal women. Research contexts also use lyophilized 10 mg vials reconstituted with BAC water.
Research-use vials: 10 mg + 2.0 mL BAC water = 5,000 mcg/mL. At this concentration, 250–500 mcg = 5–10 units on a U-100 syringe.
The FDA label for Vyleesi specifies SC administration in the abdomen or thigh, at least 45 minutes before anticipated sexual activity. No more than one dose per 24 hours.
Sources
Every factual claim above resolves to a real, published source.
- Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 TrialsObstetrics & Gynecology, 2019, PMID 31599840
- Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire DisorderObstetrics & Gynecology, 2019, PMID 31599847
- VYLEESI (bremelanotide injection) Full Prescribing InformationFDA Label, Initial U.S. Approval 2019 (NDA 210557)
- Re-Analyzing Phase III Bremelanotide Trials for 'Hypoactive Sexual Desire Disorder' in WomenJournal of Sex Research, 2021, PMID 33678061
Cite this page
PepCue. “PT-141: the evidence.” PepCue, reviewed June 1, 2026. https://www.pepcue.app/p/pt-141.
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