# Doctor PT-141 — Independent summaries of bremelanotide research

> An editorial reading room for bremelanotide (PT-141), the FDA-approved melanocortin-4 receptor agonist for premenopausal HSDD. Trials, mechanism, label dosing, safety — distilled.

**PT-141, distilled: the trial record on the only FDA-approved melanocortin agonist for sexual desire**

Bremelanotide (PT-141) is a centrally-acting MC4R agonist approved in 2019 for premenopausal hypoactive sexual desire disorder. This reading room summarizes what the RECONNECT trials, the label, and the surrounding literature actually show.

## What PT-141 is

PT-141 is the research code name for bremelanotide, a synthetic cyclic seven-amino-acid peptide derived from alpha-melanocyte-stimulating hormone (alpha-MSH) [1]. It is the only melanocortin-receptor agonist currently approved by the US Food and Drug Administration for a sexual-function indication: premenopausal acquired, generalized hypoactive sexual desire disorder (HSDD), approved June 21, 2019 under NDA 210557 [9].

The approved formulation is a 1.75 mg subcutaneous injection delivered by single-use autoinjector into the abdomen or thigh, taken as-needed at least 45 minutes before anticipated sexual activity [9]. Two doses must be separated by at least 24 hours, and no more than eight doses are recommended in any 28-day period [9][11].

Unlike phosphodiesterase-5 inhibitors such as sildenafil, which work peripherally on smooth-muscle blood flow, bremelanotide works centrally. Its primary therapeutic action is agonism at melanocortin-4 receptors (MC4R) in the hypothalamus — the brain region that organizes sexual motivation and the appetitive component of desire [5][16].

## Why a separate site for an approved drug

Most peptides circulating in online discussions are unapproved research chemicals. PT-141 is not. It has a Phase 3 program (RECONNECT, N=1,202), a 52-week open-label extension, a 3,500-subject safety database, and an FDA label that runs to specific contraindications, dose caps, and adverse-event frequencies [1][2][3][9][11].

That makes the literature both richer and more tightly scoped than for typical research peptides. Everything on this site is sourced from peer-reviewed publications, regulatory documents, or named investigator press releases — each claim links to the underlying citation on the references page.

This is not a clinic. It is an editorial project. We do not sell PT-141, we do not provide medical advice, and we do not refer patients to anyone who does. The information here is meant to make the published record easier to read.

## What the RECONNECT trials showed

RECONNECT was the umbrella name for two identically-designed Phase 3 trials (Studies 301 and 302; NCT02333071 and NCT02338960) enrolling 1,202 premenopausal women with HSDD across the United States and Canada [1].

Women randomized to 1.75 mg bremelanotide on-demand showed a least-squares mean improvement of +0.35 points on the FSFI-Desire domain and -0.33 on the FSDS-DAO Item 13 (distress) over 24 weeks, both versus placebo, both at P<0.0001 [1]. Secondary FSFI analyses subsequently published in 2025 found arousal-domain scores improved 23-25% over baseline at four weeks (vs 5-10% on placebo) and orgasm scores 16-21% (vs 0-9%), with the gap widening through 24 weeks [14].

A 52-week open-label extension followed: 684 of the roughly 856 women who completed the double-blind phase elected to continue, and 272 finished the full extension [2][18]. No new safety signals emerged, and women who had received drug during the double-blind phase continued to improve [2].

## Safety profile in one paragraph

The two dominant adverse events are nausea (about 40% of users vs ~1% on placebo, median onset within one hour, median duration ~2.4 hours) and flushing (about 20% vs ~1%) [3][12]. Headache, injection-site reactions, and a small transient blood-pressure increase (approximately +3 mmHg systolic, +2 mmHg diastolic, resolving within 8-12 hours) round out the common profile [3][10]. Focal hyperpigmentation — discrete darkening of skin, gums, or breasts — occurs in about 1% of patients and is the reason the label caps dosing at eight per 28-day period [11]. The label contraindicates use in uncontrolled hypertension or known cardiovascular disease [10].

## Where to go from here

The [research](/research) page is the long form: mechanism, RECONNECT design and results, neuroimaging evidence, and the in-progress obesity and combination-ED programs. The [dosage](/dosage) page summarizes the label-specified regimen, pharmacokinetics, and the historical dose-finding work that led to it. The [FAQ](/faq) addresses the questions that come up most often — including the difference between PT-141 and the brand-name approved product, off-label use, and how the central mechanism differs from PDE5 inhibitors.

## References

[1] Kingsberg SA, Clayton AH, Portman D, Williams LA, Krop J, Jordan R, Lucas J, Simon JA. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstetrics & Gynecology. 2019. — doi: 10.1097/AOG.0000000000003500 — https://pubmed.ncbi.nlm.nih.gov/31599839/
[2] Simon JA, Kingsberg SA, Portman D, Williams LA, Krop J, Jordan R, Lucas J, Clayton AH. Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder. Obstetrics & Gynecology. 2019. — doi: 10.1097/AOG.0000000000003514 — https://pubmed.ncbi.nlm.nih.gov/31599847/
[3] Clayton AH, Kingsberg SA, Portman D, Sadiq A, Krop J, Jordan R, Lucas J, Simon JA. Safety Profile of Bremelanotide Across the Clinical Development Program. Journal of Women's Health. 2022. — doi: 10.1089/jwh.2021.0191 — https://pubmed.ncbi.nlm.nih.gov/35230116/
[5] Thurston L, Hunjan T, Mills EG, Wall MB, Ertl N, Phylactou M, Muzi B, Patel B, Alexander EC, Suladze S, Modi M, Eng PC, Bassett PA, Abbara A, Goldmeier D, Comninos AN, Dhillo WS. Melanocortin 4 receptor agonism enhances sexual brain processing in women with hypoactive sexual desire disorder. The Journal of Clinical Investigation. 2022. — doi: 10.1172/JCI152341 — https://www.jci.org/articles/view/152341
[9] Bremelanotide injection US Prescribing Information. US FDA Approved Label, NDA 210557. 2019. — https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
[10] Bremelanotide Prescribing Information: Section 5 Warnings and Precautions. US FDA Approved Label, NDA 210557. 2019. — https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
[11] Bremelanotide Prescribing Information: Section 5.2 Focal Hyperpigmentation. US FDA Approved Label, NDA 210557. 2019. — https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
[12] Edinoff AN, Sanders NM, Lewis KB, Apgar TL, Cornett EM, Kaye AM, Kaye AD. Bremelanotide for Treatment of Female Hypoactive Sexual Desire. Neurology International. 2022. — doi: 10.3390/neurolint14010006 — https://www.mdpi.com/2035-8377/14/1/6
[14] RECONNECT investigators. Positive Effects of Bremelanotide on Female Sexual Arousal and Orgasm in Premenopausal Women with HSDD: FSFI Data from the RECONNECT Trials. The Journal of Sexual Medicine (Supplement). 2025. — doi: 10.1093/jsxmed/qdaf068.108 — https://academic.oup.com/jsm/article/22/Supplement_1/qdaf068.108/8119524
[16] Pfaus JG, Sadiq A, Spana C, Clayton AH. The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women. CNS Spectrums. 2022. — doi: 10.1017/S109285292000219X — https://pubmed.ncbi.nlm.nih.gov/33455598/
[18] Simon JA, Kingsberg SA, Portman D, et al. Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder (open-label extension enrollment data). Obstetrics & Gynecology. 2019. — doi: 10.1097/AOG.0000000000003514 — https://pubmed.ncbi.nlm.nih.gov/31599847/

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Not medical advice. This site does not sell any product and is not affiliated with any vendor or manufacturer.