Peptides

PT-141 / bremelanotide: the one "women's peptide" that is an approved drug — and the gray market trading on its name

By the US Health Digest editorial team · Published August 12, 2026 · Every claim linked to its primary source

Bremelanotide — the peptide sold online as "PT-141" — is the rare compound in the peptide market with an actual FDA approval for a women's indication. FDA approved it on June 21, 2019, as Vyleesi, for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. The approval is real; so are the limits. In the phase 3 trials, desire scores rose 0.5–0.6 points versus 0.2 on placebo, on a scale spanning 4.8 points, and 40% of treated women reported nausea. And the "research use only" PT-141 vials and nasal sprays sold online are not this product — they are unapproved copies with no verified manufacturing behind them. We publish no dosing for gray-market products.

The approval, precisely

Vyleesi (bremelanotide injection) is a melanocortin receptor agonist approved under NDA 210557 — Drugs@FDA records the original approval on June 21, 2019. The approval letter defines the indication narrowly: premenopausal women with acquired, generalized HSDD — low sexual desire causing marked distress or interpersonal difficulty that is not due to a medical or psychiatric condition, relationship problems, or a medication. The label's stated limitations of use: not indicated for postmenopausal women or for men, and not indicated to enhance sexual performance.

The approved product is specific: a 1.75 mg/0.3 mL single-dose autoinjector, injected under the skin of the abdomen or thigh as needed, at least 45 minutes before anticipated sexual activity — no more than one dose per 24 hours, and more than 8 doses per month is not recommended. The label also tells prescribers to stop the drug after 8 weeks if symptoms have not improved. Subcutaneous injection is the only approved form; no bremelanotide nasal spray has ever been approved.

What the trials showed — the honest version

The approval rests on RECONNECT: two identical randomized, double-blind, placebo-controlled phase 3 trials, published by Kingsberg and colleagues in Obstetrics & Gynecology in 2019. Of 1,267 premenopausal women randomized 1:1 to as-needed bremelanotide 1.75 mg or placebo for 24 weeks, 1,202 formed the modified intent-to-treat (MITT) efficacy population. The co-primary endpoints were change in the FSFI desire domain (a 1.2-to-6.0 scale built from two questions about how often and how strongly you felt desire) and FSDS-DAO item 13 (how often you felt bothered by low desire, scored 0–4).

The results were statistically significant and numerically small. Per the FDA label's tables (MITT population, versus placebo): desire scores rose a mean of 0.5 points in Study 1 and 0.6 in Study 2, against 0.2 on placebo in both — from a baseline near 2.0 on that 1.2-to-6.0 scale. Distress scores fell 0.7 points versus 0.4 on placebo in both studies, on the 0–4 scale. The integrated placebo-adjusted differences in the published paper: +0.35 for desire and −0.33 for distress (both p<.001, MITT). The median tells the same story more plainly: the median treated woman's desire score rose 0.6 points; the median placebo patient's did not change at all.

Two more label facts belong in any honest account. First, dropout was lopsided: 40% versus 13% (Study 1) and 39% versus 25% (Study 2) of MITT patients on drug versus placebo quit the 24-week double-blind period early. Second, use was occasional, not daily: the median woman took 10 injections over 24 weeks — fewer than twice a month on average. In the 52-week open-label extension (684 enrolled, 272 completed; all analyses descriptive, no placebo arm), improvements persisted in those who stayed.

The safety facts on the label

Nausea is the headline number: reported by 40% of treated patients in the placebo-controlled trials, requiring anti-emetic therapy in 13% and driving 8% to quit the trials — in the extension study it was 40.4%, and the only severe adverse event reported by more than one participant in both studies. Beyond nausea, the label documents:

• Blood pressure. Every dose transiently raises blood pressure — maximal increases of 6 mmHg systolic and 3 mmHg diastolic, peaking 2–4 hours post-dose, with heart rate dropping up to 5 beats per minute, usually resolving within 12 hours. The drug is contraindicated in uncontrolled hypertension or known cardiovascular disease, and not recommended at high cardiovascular risk.
• Focal hyperpigmentation. Dark patches on the face, gums, or breasts in 1% of patients at up to 8 doses a month — but 38% of patients dosed daily for just 8 days, with higher risk in darker skin, and resolution "not confirmed in all patients" after stopping. This is the label's core argument against the frequent-use patterns gray-market sellers imply.
• Drug interactions. It slows gastric emptying (affecting absorption of oral drugs) and can sharply reduce exposure to oral naltrexone — a real hazard for women taking naltrexone for alcohol or opioid use disorder.

Is it still on the market? Yes — under a new owner

Developer Palatin Technologies announced on December 20, 2023, that it had completed the sale of Vyleesi — $12 million upfront plus up to $159 million in sales milestones — to Cosette Pharmaceuticals, which confirmed the acquisition on January 3, 2024 and stated its commitment to keep marketing it. The federal records agree: Drugs@FDA lists Cosette as the current applicant with prescription marketing status, and the current label on DailyMed carries Cosette's name. So an FDA-approved, prescription bremelanotide product exists right now — which makes the gray market a choice, not a necessity.

The gray market: "PT-141" vials and sprays

Search "PT-141" and you will find vials of lyophilized powder and "nasal sprays" sold with research-use-only disclaimers. FDA has stated what that disclaimer is worth when a storefront's own marketing tells the real story: in a March 2026 warning letter to a peptide vendor, the agency wrote that despite "Research Use Only" labeling, "evidence obtained from your website establishes that your products are intended to be drugs for human use." And FDA has named this peptide directly at least once: an April 2020 warning letter to Tailor Made Compounding LLC lists "Bremelanotide (PT-141)" among more than twenty substances the pharmacy compounded with, in violation of section 503A's conditions — conduct FDA observed at a 2018 inspection, before Vyleesi's approval, when no bremelanotide product was a component of any approved drug.

What is actually in such vials? No published test-purchase study has assayed gray-market PT-141 specifically — we searched PubMed and found none. The evidence from the online peptides researchers did buy and test is not reassuring. A 2015 study purchased melanotan II — the unapproved tanning peptide bremelanotide was developed from — from three internet shops and found every vial underfilled, holding 4.32 to 8.84 mg against the 10 mg each label claimed. A 2024 study in the Journal of Medical Internet Research bought "semaglutide" — a different peptide — from illegal online pharmacies and measured it: purity of 7.7% to 14.37% against the 99% claimed on the labels, with bacterial endotoxin detected in every sample. That is what "research grade" has meant in the cases researchers checked. Our guide to certificates of analysis and peptide safety covers why a vendor's own purity paperwork does not resolve this.

The compounding picture differs from peptides like CJC-1295 and ipamorelin, which are unapproved substances fighting for a place on FDA's bulk-substances lists — bremelanotide does not appear anywhere on FDA's compounding risk-category page, because as a component of an approved drug it does not need a nomination. Instead the constraint runs the other way: under section 503A, compounders may not regularly produce drugs that are "essentially copies of a commercially available drug product." With Vyleesi commercially available, a compounded or "research" copy is not filling a gap — it is duplicating an approved drug without the manufacturing oversight.

The bottom line

PT-141 is the unusual case where the peptide market's promise — "this one is FDA-approved" — is true, for one product, one population, one indication. The honest numbers are a roughly one-third-of-a-point average gain in desire over placebo, a 40% nausea rate, blood-pressure effects that rule out some women entirely, and a pigmentation risk that grows with exactly the kind of frequent use no prescriber would sanction. Anyone considering it should be talking to a clinician about the approved autoinjector — not reconstituting a vial sold under a disclaimer. For the wider context, start with what peptides actually are, what peptide clinics charge, and why the proven end of this class — the GLP-1 drugs — went through the trials this market skips.