Sexual and Reproductive Health
Approved versus promoted peptides for sexual and reproductive health: bremelanotide (PT-141) trials and label, oxytocin, kisspeptin research, and Melanotan II warnings, with limits and funding.
Content last updated . This page has not been medically reviewed.
Evidence labels used here. Approved medicine: a regulator approved it for a named use. Promising but limited: some human data, small or short. Mixed: results disagree. No good evidence of benefit: a good trial found no difference from placebo. Insufficient evidence: too little to judge. Proper evidence not found: we looked and found nothing usable. Brain-scan activity or a hormone level is a biomarker; more satisfying sex or less distress is a clinical outcome.
For everyday guidance, see Low Libido in Men, Erectile Dysfunction, Vaginal Dryness and Sexual Wellness and Perimenopause and Menopause. Other approved reproductive peptide medicines are on Endocrine and Reproductive Peptide Medicines.
Bremelanotide, also called PT-141
Identity and naming. Bremelanotide is a synthetic peptide analog of the natural hormone alpha-MSH. [1] A 2006 trial paper names it "bremelanotide (PT-141)", so PT-141 is a development name for the same compound. [2] A seller using "PT-141" does not make a product the approved Vyleesi pen, and this page cannot confirm what an online product contains.Regulatory (United States). The DailyMed label for Vyleesi (initial US approval 2019, read 2026-10-22) covers premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), meaning low desire that causes marked distress and is not explained by another condition, relationship problems or a medication. [3] The label says it is not indicated for HSDD in postmenopausal women or in men, and not to enhance sexual performance. [3] Other countries were not checked here.
Trial evidence.
| Study | Population and design | Result | Funding and limits |
|---|---|---|---|
| RECONNECT, two identical phase 3 trials (2019) | 1,267 premenopausal women with HSDD randomized 1 to 1 to bremelanotide or placebo for 24 weeks [4] | Desire scores rose about 0.35 more than placebo and distress scores fell about 0.33 more (integrated results); nausea, flushing and headache occurred in 10% or more [4] | Funded by Palatin Technologies and AMAG Pharmaceuticals. [4] Mostly white (85.6%) women from US sites (96.6%). [4] The main outcomes were questionnaire scores. |
| Single-dose nasal study (2006) | 18 premenopausal women with arousal disorder, double-blind crossover [2] | More women reported moderate or high desire after bremelanotide than placebo; physical vaginal blood-flow change was not significant [2] | Small, one dose, nasal route, whereas the approved product is an injection. [3] |
Evidence label: approved medicine for the labeled group; promising but limited in terms of how large the average benefit is. A meta-analysis of female sexual dysfunction drug trials, which included bremelanotide among other products, estimated that about 68% of the treatment effect on the Female Sexual Function Index was accounted for by placebo. [5]
Major label safety information. The label lists contraindication in uncontrolled high blood pressure or known cardiovascular disease. [3] It transiently raises blood pressure and lowers heart rate after each dose. [3] Nausea was reported by 40% of patients in the label's data, and focal hyperpigmentation (patches of darker skin, including face, gums and breasts) was reported in 1% in phase 3 trials. [3] Prescribing questions belong to a clinician.
Melanotan II
Melanotan II is a separate compound, not Vyleesi. On the FDA bulk-compounding page (content current as of 04/22/2026, read 2026-10-22) FDA says published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism (a painful, prolonged erection). [6] Evidence label: insufficient evidence of benefit, with harm reports in case reports. Approval status elsewhere was not verified. Please see a clinician urgently for a prolonged, painful erection, severe headache with vision changes or confusion, or a changing mole.Kisspeptin
Kisspeptin is a natural hormone that activates the reproductive hormone axis. [7] Two UK placebo-controlled crossover trials gave a single 75-minute infusion into a vein. [7][8] In 32 women with HSDD, brain-scan responses to erotic and face images changed, and no adverse effects were reported. [7] In 32 men with HSDD, brain activity changed and penile tumescence in response to sexual stimuli increased compared with placebo. [8] These are biomarker studies in a lab, with a short exposure and small groups. Evidence label: promising but limited; insufficient evidence for lasting benefit. The trials used kisspeptin-54. FDA's bulk-compounding page lists a different form, Kisspeptin-10, in category 2 for 503A compounding (date added September 29, 2023), citing immunogenicity concerns. [6] Forms are not interchangeable.Oxytocin
Oxytocin has an approved role in pregnancy care: the Pitocin label covers starting or improving uterine contractions for labor, and says it is not indicated for elective induction. [9] That is a different use and route from nasal sprays sold for bonding or sex. In a crossover trial of 30 pre- and postmenopausal women with sexual dysfunction, both oxytocin and placebo improved function over time with no difference between them. [10] Evidence label: no good evidence of benefit for this use in that trial. A large autism trial of intranasal oxytocin was also negative; see Neurological and Cognitive Research.Reproductive health beyond sexual function
Kisspeptin-54 has also been tested inside fertility clinics as an injected trigger for egg maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS, a complication of IVF). A 2015 phase 2 trial randomized 60 such women to four dose levels with no placebo group: oocyte maturation occurred in 95%, live births per embryo transfer were 45% across doses, and no woman developed moderate or severe OHSS. [11] A 2017 placebo-controlled trial of 62 women found that a second dose raised the share with a high egg yield (71% versus 45%). [12] These were single-center, specialist-supervised studies of a defined molecule, not evidence for products sold online. Evidence label: promising but limited.Other peptide medicines used in reproductive care have their own labels; see the Endocrine and Reproductive page linked above. For male fertility see Male Fertility.
Frequently asked questions
Is PT-141 the same as Vyleesi?
PT-141 is a development name for bremelanotide, the active ingredient in Vyleesi. A product sold as PT-141 is not necessarily the approved medicine. [2][3]
Who is bremelanotide approved for?
In the US, premenopausal women with acquired, generalized HSDD. It is not indicated for men or postmenopausal women. [3]
Does it work well?
In two large trials it improved desire and distress scores more than placebo, by small average amounts, and a pooled analysis shows placebo accounts for much of the effect seen with many such drugs. [4][5]
Is kisspeptin a proven treatment for low desire?
No. Early crossover studies showed changes in brain activity and arousal measures after one infusion. [7][8]
Is Melanotan II safe?
FDA's page cites case reports of serious adverse events and lists it as a compounded-drug safety concern. [6]
References
- Bremelanotide: First Approval. Drugs 2019. PubMed abstract read 2026-10-22.
- An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist. J Sex Med 2006. PubMed abstract read 2026-10-22.
- VYLEESI (bremelanotide) injection, prescribing information (DailyMed, Cosette Pharmaceuticals; version published 2025-11-18). Read 2026-10-22.
- Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol 2019. PubMed abstract read 2026-10-22.
- Female Sexual Dysfunction and the Placebo Effect: A Meta-analysis. Obstet Gynecol 2018. PubMed abstract read 2026-10-22.
- FDA, Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (page content current as of 04/22/2026). Read 2026-10-22.
- Effects of Kisspeptin Administration in Women With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open 2022. PubMed abstract read 2026-10-22.
- Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open 2023. PubMed abstract read 2026-10-22.
- PITOCIN (oxytocin) injection, prescribing information (DailyMed, Par Health; version published 2026-05-21). Read 2026-10-22.
- Effect of long-term intranasal oxytocin on sexual dysfunction in premenopausal and postmenopausal women: a randomized trial. Fertil Steril 2015. PubMed abstract read 2026-10-22.
- Efficacy of Kisspeptin-54 to Trigger Oocyte Maturation in Women at High Risk of Ovarian Hyperstimulation Syndrome (OHSS) During In Vitro Fertilization (IVF) Therapy. J Clin Endocrinol Metab 2015. PubMed abstract read 2026-10-22.
- A second dose of kisspeptin-54 improves oocyte maturation in women at high risk of ovarian hyperstimulation syndrome: a Phase 2 randomized controlled trial. Hum Reprod 2017. PubMed abstract read 2026-10-22.