Product Description

PT-141, also known as bremelanotide, is a cyclic peptide that interacts with melanocortin receptors. Much of the research around PT-141 has focused on what happens in the central nervous system, particularly through MC4R signalling.

This is an important part of the story.

Sexual response is not controlled by blood flow alone. Neural pathways matter too, and bremelanotide gave researchers a way to study that side of the process. The activity of PT-141 at melanocortin receptors in the brain has therefore been investigated in relation to sexual desire, arousal and erectile response.

The mechanism is still not fully understood. What studies do show is that melanocortin signalling — especially pathways involving MC4R — plays a role in the biological processes behind sexual response.

Researchers have used PT-141 to explore whether sexual desire and arousal can be influenced through neural signalling rather than simply through changes in blood flow. Early experimental work moved into human studies, including research involving both men and women.

Why Study PT-141?

Much of the research started with a fairly direct question: can melanocortin signalling in the brain influence sexual response?

Evidence suggested that it could.

A preliminary double-blind study looked at bremelanotide in healthy men and in men who had mild-to-moderate erectile dysfunction. At doses above 7 mg, erectile responses from intranasal PT-141 peptide were noticeably greater than those from placebo. The first noticeable response happened around thirty minutes after the spray. The common side effects were nausea and flushing. These early findings made intranasal PT-141 particularly interesting to researchers studying erectile response.

The mechanism was unusual enough to keep researchers interested. It wasn't simply another vascular approach.

In a separate randomized trial, 342 men with erectile dysfunction who did not respond to sildenafil were studied. 33.5% of participants receiving bremelanotide, reported positive clinical results compared to 8.5% of participants receiving placebo. The active-treatment group also reported higher satisfaction with intercourse, but drug-related adverse effects were more common.

Then research grew substantially in women.

In a small early study, premenopausal women with sexual arousal disorder reported moderate to high sexual desire more often after treatment with bremelanotide, than placebo. Satisfaction with their level of arousal was also significantly greater for those who attempted intercourse in the 24 hours following the peptide. Interestingly, the measured vaginal vasocongestion response was not significantly different from placebo.

That finding raised another question. Subjective desire and physiological response may not be the same thing.

Larger studies followed.

Research Applications

Melanocortin Receptor Signalling

PT-141 has been studied as a tool for understanding the melanocortin receptor system, particularly signalling associated with MC4R in the central nervous system.

MC3R and MC4R are often called neural melanocortin receptors because of their substantial expression in the CNS. This makes melanocortin agonists such as bremelanotide useful research compounds for investigating how receptor activation can translate into behavioural and neuroendocrine responses.

The pathway is broader than sexual function alone. Melanocortin signalling is involved in several areas of physiology, which is one reason receptor selectivity and downstream signalling remain active research topics for PT-141 and related melanocortin ligands.

Female Sexual Desire and Arousal

This became the largest clinical research programme involving PT-141.

A randomized dose-escalation study randomized 327 women to placebo or different doses of subcutaneous bremelanotide. The combined 1.25 mg and 1.75 mg groups had an increase of 0.7 satisfying sexual events per month, compared with 0.2 with placebo. The Female Sexual Function Index score improved by 3.6 points vs 1.9 points with placebo, and the sexual distress score also improved to a greater extent.

Then came the two Phase 3 RECONNECT trials.

Together they randomized 1,267 premenopausal women with hypoactive sexual desire disorder (HSDD). Statistically significant improvements in sexual desire scores and reduction in distress associated with low desire were observed in bremelanotide groups compared with placebo.

Male Sexual Response

Earlier PT-141 research also explored the melanocortin pathway in men with erectile dysfunction.

This was scientifically interesting because the approach differed from phosphodiesterase-5 inhibitors such as sildenafil. Instead of concentrating primarily on peripheral vascular signalling, researchers were investigating a centrally acting pathway involved in sexual response.

Results from early placebo-controlled studies of bremelanotide, showed measurable erectile responses and provided evidence for further investigation. Later research, however, shifted much more strongly toward female HSDD.

Central Nervous System Research

The activity of PT-141 also makes it relevant for broader studies of central melanocortin signaling.

To investigate receptor pharmacology, neural signaling, and the biological functions of MC3R and MC4R, researchers use melanocortin receptor agonists. Bremelanotide is an analog of α-MSH and part of a larger family of synthetic melanocortin ligands for research purposes.

Available Forms

PT-141 can appear in several formats depending on whether the material is intended as a laboratory reference compound or exists as a regulated pharmaceutical formulation.

Common forms include:

Lyophilized peptide vial – a freeze-dried format commonly used for laboratory research and controlled experimental preparation.
Liquid vial – a pre-prepared solution used by some research suppliers.
Nasal spray – an intranasal formulation used in several early clinical studies of the compound.
Peptide pen / syringe pen – a convenient format that can provide measured delivery, reduce manual preparation steps and make repeated handling more consistent.
Prefilled autoinjector – the format used by the FDA-approved bremelanotide medicine Vyleesi.

Researchers looking to buy PT-141 peptide online may encounter different research formats, depending on the supplier and the intended laboratory workflow.

The pharmaceutical autoinjector and research PT-141 products should not be treated as interchangeable. They differ in regulatory status, manufacturing requirements and intended use.

Research Use Only

Research-grade bremelanotide, is intended solely for laboratory and scientific research. It is not the same thing as an approved pharmaceutical product and should not be presented as a substitute for one.

Published human studies discussed on this page describe the scientific history and clinical investigation of bremelanotide as a compound. They do not establish the safety, efficacy or suitability of research-grade PT-141 peptide material for human or veterinary use.

Listings describing PT-141 injections for sale should therefore be evaluated according to the specific product format, intended research use and accompanying documentation.

Laboratory work should follow appropriate institutional protocols, handling procedures and applicable regulations.

Scientific References

Kingsberg et al. Obstet Gynecol, 2019 – RECONNECT Phase 3. PubMed
Clayton et al. Women's Health, 2016 – Dose-finding study. PubMed
Diamond et al. J Sex Med, 2006 – Female desire and arousal. PubMed
Diamond et al. Int J Impot Res, 2004 – Intranasal PT-141 in men. PubMed
Safarinejad & Hosseini. J Urol, 2008 – Erectile dysfunction study. PubMed

PT-141 (Bremelanotide Peptide)