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Not medical advice. The Atlas is not a substitute for a clinician who can examine you.

PT-141

Bremelanotide · Melanocortin Agonist (Vyleesi)

Evidence grade 4 of 5, Strong. Read how the Atlas grades evidence.

For the narrow FDA-approved indication (acquired, generalized HSDD in premenopausal women), bremelanotide rests on two identical phase 3 RCTs (RECONNECT, studies 301/302, N~1,267, Kingsberg et al., Obstet Gynecol 2019) that met both co-primary endpoints for desire and distress, which supports grade 4. The effect is modest and contested: FSFI-desire differences versus placebo were about 0.30 to 0.42, LiverTox describes the improvement as 'rather modest,' and a critical re-analysis (Spielmans, J Sex Res 2021) found participants preferred placebo overall and reported a number-needed-to-harm of 6 for adverse-event discontinuation, so it does not reach grade 5. The gray-market injectable 'PT-141' marketed for general libido or male erectile dysfunction is off-label and unapproved and rests on far weaker human evidence (grade 1 to 2).

FDA
FDA approved June 2019 as Vyleesi (bremelanotide injection, 1.75 mg subcutaneous) for acquired, generalized HSDD in premenopausal women; off-label injectable PT-141 for male ED or general libido is unapproved, and compounded PT-141 (including nasal spray) is not FDA-approved.
WADA
Not prohibited (not named on the 2026 WADA Prohibited List)

Reference only. Not medical advice.

What can go wrong

Nausea (~40%, dominant), flushing (~20%), injection-site reactions (~13%), headache (~11%); transient BP rise with reflex heart-rate drop; focal hyperpigmentation (~1%, face/gums/breasts, not always reversible).

Talk to a clinician before taking this, particularly if you have a heart condition. The Atlas can tell you what has been studied about PT-141. It cannot tell you how it would interact with your body, your history, or anything else you are taking, and nothing on this page is a reason to start.

A melanocortin receptor agonist derived from Melanotan II research. FDA-approved in 2019 (Vyleesi) for hypoactive sexual desire disorder in premenopausal women, and widely used off-label by men. Works centrally in the brain rather than peripherally like Viagra.

The only FDA-approved peptide for sexual dysfunction, and the one most used off-label.

What people take it for

What it is taken for. Approval, where it exists, covers only some of these.

  • Female HSDD (FDA approved)
  • Male erectile dysfunction / libido (off-label)
  • Arousal in both sexes
HSDD in premenopausal women (Vyleesi)
FDA-approved in June 2019 for acquired, generalized hypoactive sexual desire disorder, dosed 1.75 mg under the skin about 45 minutes before activity, up to eight times a month. One of only two approved drugs for female sexual dysfunction.

How it works

PT-141 works in the brain, not the bloodstream, which sets it apart from every Viagra-style drug. It activates melanocortin receptors, chiefly MC4R, in regions of the hypothalamus and limbic system that govern sexual motivation and reward. The result is an increase in desire and arousal driven centrally, through the wanting side of sexuality, rather than by widening blood vessels the way PDE5 inhibitors do. Because the effect is on drive itself and is independent of estrogen or testosterone, it can work in people whose hormone levels look normal but whose central sexual drive is low.

PT-141, or bremelanotide, is a small cyclic peptide of seven amino acids, a constrained analog of the natural hormone alpha-MSH, developed by Palatin Technologies. Its small, ring-shaped structure gives it predictable absorption under the skin and lets it cross the blood-brain barrier in meaningful amounts, which is essential for a drug that has to act centrally. It is chemically a refinement of the tanning peptide Melanotan II: the part most responsible for skin pigmentation was trimmed to focus the molecule on sexual function, though it still touches the pigmentation receptor enough to matter.

Type
Melanocortin agonist
Size
7 amino acids
Acts on
MC4R (central)
Route
Subcutaneous
Timing
~45 min before
Status
Approved (Vyleesi)

Approved For Few, Bought By Many

PT-141 is the most medically validated peptide in the consumer sexual-health space, and that pedigree is precisely what gets stretched. Its FDA approval is narrow: premenopausal women with acquired, generalized low desire. Yet most of the gray-market and telehealth use is in men, for erectile and libido complaints, and in recreational "desire on demand," where Phase 3 evidence simply does not exist; the human data outside the approved female indication is Phase 2 at best. The second omission is effect size. Even in its approved use the benefit is real but modest, roughly a quarter of women counted as responders versus about a sixth on placebo. And the side effects are not trivial: nausea in about 40% of users, a transient rise in blood pressure that rules it out in heart disease, and skin and gum darkening with repeated use. A real drug, a real but moderate effect, used far beyond the narrow group it was actually proven in.

Safety in detail

Vyleesi carries a warning for transient increases in blood pressure and reductions in heart rate after each dose; it is contraindicated in uncontrolled hypertension or known cardiovascular disease, and is limited to no more than one dose per 24 hours and eight per month. Focal hyperpigmentation was reported in about 1% of trial patients and did not always resolve after discontinuation, and one possible case of drug-associated acute hepatitis was recorded (LiverTox likelihood D). Adverse-event-driven discontinuation was substantially higher than placebo, and unregulated gray-market PT-141 carries additional purity and dosing risks.

  • Nausea is by far the most common effect, in roughly 40% of users, usually within hours and resolving the same day; anti-nausea pretreatment can help but may blunt the effect.
  • A transient rise in blood pressure with a small fall in heart rate is expected, which is why it is limited to eight doses a month and is not for people with uncontrolled hypertension or established cardiovascular disease.
  • Focal hyperpigmentation, darkening of skin or gums, can occur with repeated use, more so in people with darker skin, from its activity at the pigmentation receptor.
  • Headache and flushing are common; injection-site reactions occur.
  • Safety beyond the approved female HSDD population and dosing is not well established, including long-term repeated use.
  • For gray-market vials, the usual unverified identity, dose and purity risks apply.
  • It is not specifically listed on the WADA Prohibited List, though athletes should always check the current code.

Children and teenagers

PT-141 is a sexual-function drug with no pediatric indication, no pediatric data, and no medical rationale for use in anyone under 18. It is approved only in adult premenopausal women and otherwise used in adults off-label. Any use in a minor would be inappropriate and unstudied, and the gray-market sourcing risks would apply on top. There is simply no context in which a melanocortin sexual-desire agonist belongs in pediatric use.

What people get wrong

Nothing recorded here yet. There is almost certainly something people get wrong about this one, and the blank space means we have not written it down, not that the record is clean.

Who profits, and who pushes back

Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.

Unlike a purely gray-market peptide, PT-141 has an approved product, Vyleesi, whose commercial rights have passed through Palatin and AMAG to Cosette Pharmaceuticals, so a regulated manufacturer profits from the female HSDD indication. The larger and faster-growing money, though, is off-label: men's-health telehealth platforms that prescribe it for erectile and libido complaints, compounding pharmacies preparing bremelanotide, and online research vendors selling vials. The approved use anchors its legitimacy; the off-label male and recreational market is where most of the volume and revenue now sit.

How we got here

PT-141 was derived from Melanotan II at Palatin Technologies after researchers observed unexpected sexual-arousal activity in the broader melanocortin agonist during pigmentation studies. Palatin refined that activity into the cleaner cyclic heptapeptide bremelanotide, which the FDA approved in June 2019 as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. The compound also circulates on the gray market under its original PT-141 code as an injectable libido peptide.

PT-141 grew out of melanocortin science and an accidental discovery. Researchers studying the tanning peptide Melanotan II noticed it produced unexpected erections, which pointed to a central role for melanocortin receptors in sexual function. Palatin Technologies developed bremelanotide from that lineage, trimming the tanning activity to focus on desire. An early intranasal version was set aside over blood-pressure concerns, and the program pivoted to a subcutaneous injection for premenopausal women with HSDD, a condition with no approved drug at the time. Vyleesi won FDA approval in June 2019. In the years since, off-label use in men and recreational use have grown rapidly through telehealth and compounding, far outpacing the approved indication.

  1. 1990s-2000sMelanocortin research; Melanotan II’s unexpected erectile effect points to a central pathway.
  2. 2000sPalatin develops bremelanotide; early intranasal version shelved over blood-pressure concerns.
  3. 2010sPivot to subcutaneous injection and the female HSDD indication; RECONNECT Phase 3 trials run.
  4. Jun 2019Vyleesi approved by the FDA for premenopausal women with HSDD.
  5. 2020sOff-label male and recreational use expand rapidly via telehealth and compounding.

The numbers behind the grade

Approved
Vyleesi, 2019
Mechanism
Central (MC4R)
Approved for
Premenopausal women, HSDD
Nausea
~40%
WADA
Not listed
Parent
Melanotan II

The people taking it

The most medically validated peptide in the consumer sexual-health world and, in practice, the best-known "libido peptide." Its fame now rests as much on widespread off-label male and recreational use as on its narrow approved indication in women.

There is a striking gap between who PT-141 is approved for and who uses it. The approved population is premenopausal women with diagnosed HSDD. The actual user base is heavily male, men using it off-label for erectile and desire problems, often through telehealth, plus recreational users of both sexes and couples seeking on-demand desire enhancement. The female-HSDD patients move through regulated prescriptions; the larger male and recreational use runs through telehealth, compounding and gray-market channels, where there is little reliable demographic data.

Approved and prescribed for premenopausal women with HSDD, and used widely off-label in men for erectile and desire problems and recreationally by both sexes for on-demand desire. Acts centrally rather than on blood flow. Not specifically prohibited in sport.

Set against the alternatives

PT-141 is best understood against three reference points. Versus PDE5 inhibitors like sildenafil and tadalafil, it is mechanistically opposite: those drugs improve the plumbing of an erection through blood flow, while PT-141 acts on desire in the brain, which is why it can help people, including men, who do not respond to PDE5 inhibitors and why the two are sometimes seen as complementary rather than competing. Versus flibanserin (Addyi), the other approved drug for female low desire, PT-141 is taken on demand before activity rather than daily, a different trade-off in convenience and side effects. And versus its own parent molecule Melanotan II, PT-141 keeps the sexual effect while shedding most of the tanning, making it the more targeted of the two. Among consumer sexual-health peptides, none can match its regulatory validation.

What we do not know

  • Whether PT-141 will ever be formally approved for men, given solid Phase 2 data but no pursued Phase 3.
  • What the long-term safety of repeated use is, particularly the pigmentation and blood-pressure effects.
  • How meaningful the modest average effect is for individual users versus placebo.
  • How to weigh the large recreational and on-demand use that sits outside any studied indication.
  • Whether on-demand desire enhancement in people without a diagnosed disorder is wise.

What could change

Male approval questionWhether anyone pursues formal approval for men, given the existing Phase 2 signal.On-demand sexual-health marketContinued growth of telehealth-driven, on-demand use beyond the approved population.Melanocortin classBroader interest in melanocortin agonists for metabolic and other effects, distinct from sexual function.Combination usePairing with PDE5 inhibitors for people who need both desire and erectile support.

The market for this

What follows describes how this is bought and sold. It is not a buying guide and it is not an endorsement of any seller.

The regulated routes are a Vyleesi prescription for the approved female indication, or an off-label prescription, often via men’s-health telehealth, filled as compounded bremelanotide by a licensed pharmacy. The unregulated route is an online research vendor selling vials as research-use-only, where an independent certificate of analysis is the only quality check. For anything resembling medical use, a prescription route is the sensible one.

The branded Vyleesi auto-injector is the most expensive route, priced per dose as a specialty prescription. Compounded bremelanotide through a pharmacy is typically cheaper and common for off-label male use. Gray-market research vials are the cheapest per milligram and the least accountable. As elsewhere, the lowest price comes with the least assurance of what is actually in the vial.

The approved product is pharmaceutical-grade and traceable. Compounded bremelanotide comes from licensed pharmacies with more oversight than vendor vials. Gray-market material is synthesized mostly in China and sold for research use, with the usual uncertainty about identity, dose and purity, so a current certificate of analysis matters for anyone going that route.

Approved product (regulated)Vyleesi is manufactured as an FDA-approved auto-injector under cGMP and dispensed by prescription, a fully traceable chain.Compounding pharmaciesLicensed 503A pharmacies can prepare patient-specific compounded bremelanotide on a prescription, common for off-label male use.China and research vendorsBulk and finished research vials are synthesized mostly in China and sold online as research-use-only, the least accountable route.Telehealth channelMen’s-health and wellness platforms bridge prescribers and compounders, driving much of the off-label supply.

At a glance

Approval
Vyleesi, 2019
Indication
Female HSDD
Mechanism
Central (brain), not vascular
Parent
Melanotan II

What this entry does not yet cover

What follows is unfinished work on our side, not a finding about PT-141.

Nothing outstanding on this one.

Sources

The studies that matter

  • RECONNECT Phase 3 trials2016-2019

    Two randomized trials in 1,267 premenopausal women with HSDD showed statistically significant gains in desire and reductions in distress, the basis for FDA approval, with a modest absolute benefit (about 25% responders versus 17% on placebo).

  • Phase 2 in men with erectile dysfunction2000s-2010s

    Dose-dependent improvement in erectile function, including in men who did not respond to PDE5 inhibitors, via the central arousal pathway, but no Phase 3 and no approval in men was pursued.

  • Preclinical melanocortin work (Pfaus and others)2000s

    Animal studies established that melanocortin agonism increases sexual solicitation behavior, confirming the central mechanism.

  • Evidence outside the approved uselimited

    There is no Phase 3 evidence for men, for postmenopausal women, or for the older intranasal route; use beyond the Vyleesi indication relies on Phase 2 data and clinical practice.