Understanding PT-141

PT-141 is also known as Bremelanotide. A melanocortin, PT-141, binds to melanocortin 4 and 1 receptors (MC-4R and MC-1R).

In 2009, scientists tested a hypothesis on PT-141 peptide for its ability to treat acute bleeding. Notably, PT-141 is a derivative of Melanotan 2, a synthetic melanocortin (MT-2).

How Does PT-141 Peptide Work?

PT-141, a cyclic heptapeptide analog, activates melanocortin. Melanocortin activation is specific to the central nervous system, and can induce erections and potentially improve sexual functions.

The peptide acts on the central nervous system but takes longer to exert its effects than PDE5 inhibitors.

PT-141, on the other hand, has a variety of mechanisms of action and functions; however, the following are its functions and how it works. 

How PT-141 Peptide can Impact Sexual Arousal and its Mechanism of Action

• PT-141 influences and stimulates the MC-4R, causing sexual arousal in the central nervous system and modulating sexual behaviors. Clinical studies show that PT-141 peptide binds to MC-4R antagonistically, which can induce sexual arousal and increase copulation in both males and females^[2].
• Despite evidence that the peptide increased various gratifying sexual events per month and significantly reduced female sexual distress scores, PT-141 was withdrawn from clinical trials in women with HSDD before FDA approval. Despite the positive results, female sexual dysfunction (FSD) specialists were disappointed because the peptide was not advanced. According to the professionals, the primary factors impeding peptide approval are a lack of established endpoints for FSD trials and sociocultural biases against women’s sexual health.
• In response to the discontinuation of earlier trials in 2017, phase II reconnects launched difficulties with subcutaneous injections of PT-141 for FSD.

MC-1R has anti-inflammatory and antifungal properties in mice models with a specific fungal infection. This is critical because standard anti-fungals limit the mechanism of action and have adverse and treatment-limiting effects in some patients. 

The MC-1R is a potent stimulator of DNA repair pathways that can potentially be used to treat and prevent cancer. Clinical studies show that people with the MC-1R variant are more likely to develop squamous and basal cell carcinoma.

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing. Bodily introduction of any sort is strictly prohibited by law. All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Kim S, Cho MC, Cho SY, Chung H, Rajasekaran MR. Novel Emerging Therapies for Erectile Dysfunction. World J Mens Health. 2021 Jan;39(1):48-64. doi: 10.5534/wjmh.200007. Epub 2020 Mar 16. PMID: 32202086; PMCID: PMC7752520.
2. Molinoff PB, Shadiack AM, Earle D, Diamond LE, Quon CY. PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Ann N Y Acad Sci. 2003 Jun;994:96-102. doi: 10.1111/j.1749-6632.2003.tb03167.x. PMID: 12851303.
3. Diamond LE, Earle DC, Rosen RC, Willett MS, Molinoff PB. Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction. Int J Impot Res. 2004 Feb;16(1):51-9. doi: 10.1038/sj.ijir.3901139. PMID: 14963471.
4. Rosen RC, Diamond LE, Earle DC, Shadiack AM, Molinoff PB. Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra. Int J Impot Res. 2004 Apr;16(2):135-42. doi: 10.1038/sj.ijir.3901200. PMID: 14999221.