PT-141 10mg

PT-141, also known as bremelanotide, is a synthetic peptide derived from the naturally occurring hormone α-melanocyte-stimulating hormone (α-MSH). Unlike other treatments for sexual dysfunction that target the vascular system, PT-141 acts directly on the central nervous system by binding to melanocortin receptors, particularly MC3R and MC4R. This mechanism has been shown to enhance sexual arousal and function in both men and women. 

PT-141 Research

PT-141 and Sexual Arousal

PT-141 is a unique peptide that stimulates the MC-4 receptor (MC-4R), which is known to trigger sexual arousal in the central nervous system and influence sexual behavior. Studies in mice have shown that agonist binding to MC-4R induces sexual arousal and increases copulation in both males and females. Because PT-141 operates through a different mechanism than drugs like Viagra, it may treat sexual arousal disorders in both men and women caused by factors other than reduced blood flow to the genitals.

A study involving men with erectile dysfunction (ED) who did not respond to sildenafil (Viagra) found that about one-third achieved adequate erections for intercourse when treated with PT-141 via nasal spray. The trial also demonstrated a strong dose-dependent response, confirming PT-141’s effectiveness in certain cases. This suggests PT-141 could provide treatment options for ED when sildenafil fails and offer insight into central nervous system causes of hypoactive sexual desire.

Interestingly, PT-141 was withdrawn from clinical trials before approval for use in women with hypoactive sexual desire disorder (HSDD), despite evidence that the drug significantly increased the number of satisfying sexual events per month and reduced female sexual distress scores without notable side effects. Many experts in female sexual dysfunction (FSD) were disappointed by the discontinuation, citing a lack of standardized trial endpoints and sociocultural biases against women’s sexual health as key obstacles preventing approval of these promising therapies. They hope increased attention will lead the FDA to establish clearer guidelines for evaluating treatments like PT-141.

Experts also noted the lack of pharmacological trials combining PT-141 with other established sexual dysfunction therapies, suggesting such combinations might produce synergistic effects. Peptides like PT-141 may help overcome initial barriers and accelerate psychological treatment approaches.

In response to concerns over trial cessation, Phase I "Reconnect" trials began in 2017 using subcutaneous injections of PT-141 for FSD. The latest version of PT-141, known as Rekynda, may soon be available in the United States. At that time, off-label use of PT-141 could legally treat sexual dysfunction in both men and women. These trials employ modified endpoints advocated by FSD experts to facilitate treatment approvals.

PT-141 and Hemorrhage

In 2009, a modified version of PT-141 was investigated as a potential treatment for hemorrhagic shock. Because PT-141 binds both MC-1R and MC-4R, it reduces ischemia and protects tissues from inadequate blood supply during hypovolemic (hemorrhagic) shock. Intravenous administration of the drug produced minimal side effects. The modified peptide, known as PL-6983, reached phase IIb clinical trials.

PT-141 and Infection

The MC-1 receptor has demonstrated important anti-fungal and anti-inflammatory properties in a rat model of fungal infection. This is especially relevant because current antifungal treatments have limited mechanisms of action and often cause serious, treatment-limiting side effects in some patients. An alternative treatment like PT-141 could significantly reduce morbidity and mortality, especially in immunocompromised individuals.

PT-141 and Cancer

The MC-1 receptor stimulates DNA repair pathways, making it relevant in cancer prevention and treatment. Research indicates that individuals with MC-1R variants face increased risks of basal cell and squamous cell carcinomas. Modified PT-141 might correct issues caused by these variants and prevent or treat these cancers.

Currently, PT-141 receives major attention for treating sexual dysfunction, but it also holds significant potential beyond sexual health and hemorrhage. For example, MC-4R defects contribute to as much as 6% of early-onset obesity cases. PT-141 offers a unique approach to exploring this cause of obesity and developing interventions. MC-1R influences pain, inflammation, kidney pathology, and infection spread. Extensive research exists where PT-141 could provide valuable insights.

PT-141 exhibits minimal side effects, low oral bioavailability, and excellent subcutaneous bioavailability in mice. Mouse dosage does not scale directly to humans. PT-141 sold by Peptide Sciences is intended for educational and scientific research only, not for human consumption. Purchases are limited to licensed researchers.

Research Applications

PT-141 is primarily utilized in scientific studies focusing on:

• Sexual Dysfunction: Investigating its effects on erectile dysfunction in men and hypoactive sexual desire disorder in women.
• Neuroendocrine Regulation: Exploring its role in modulating sexual behavior through central nervous system pathways.
• Pharmacodynamics: Studying its interaction with melanocortin receptors and subsequent physiological responses.

Product Specifications

• Form: Lyophilized (freeze-dried) powder for reconstitution.
• Dosage: Each vial contains 10mg of PT-141.
• Purity: Typically ≥99%, ensuring high-quality material for research purposes.
• Packaging: Available in sealed vials containing 10mg of PT-141.
• Storage: Store lyophilized PT-141 at temperatures below -18°C. After reconstitution, store at 4°C and use within 2-7 days.

Safety and Handling

PT-141 is intended strictly for laboratory research and is not approved for human consumption. Handle with care, following appropriate safety protocols. Ensure proper storage conditions to maintain the integrity and efficacy of the compound.

References

• M. Sandrock, A. Schulz, C. Merkwitz, T. Schoneberg, K. Spanel-Borowski, and A. Ricken, “Reduction in corpora lutea number in obese melanocortin-4-receptor-deficient mice,” Reprod. Biol. Endocrinol., vol. 7, p. 24, Mar. 2009. 
• R.C. Rosen, L.E. Diamond, D.C. Earle, A.M. Shadiack, and P.B. Molino, “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., vol. 16, no. 2, pp. 135–142, Apr. 2004. 
• H. Wessels, V.J. Hruby, J. Hackett, G. Han, P. Balse-Srinivasan, and T.W. Vanderah, “Ac-Nle-c{Asp-His-DPhe-Arg-Trp-Lys}-NH2 induces penile erection via brain and spinal melanocortin receptors,” Neuroscience, vol. 118, no. 3, pp. 755–762, 2003. 
• A-S. Rossier, J.G. Pfaus, H.K. Kia, J. Bemabé, L. Alexandre, and F. Giuliano, “The melanocortin agonist, melanotan II, enhances proceptive sexual behaviors in the female rat,” Pharmacol. Biochem. Behav., vol. 85, no. 3, pp. 514–521, Nov. 2006. 
• M.R. Safarinejad and S.Y. Hosseini, “Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo-controlled study,” J. Urol., vol. 179, no. 3, pp. 1066–1071, Mar. 2008. 
• A.H. Clayton et al., “Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial,” Womens Health (Lond. Engl.), vol. 12, no. 3, pp. 325–337, 2016. 
• M.K. Miller, J.R. Smith, J.J. Norman, and A.H. Clayton, “Expert opinion on existing and developing drugs to treat female sexual dysfunction,” Expert Opin. Emerg. Drugs, vol. 23, no. 3, pp. 223–230, 2018. 
• “AMAG Pharmaceuticals and Palatin Technologies Enter Into Exclusive Licensing Agreement for North American Rights to Rekynda™ (bremelanotide), a Potential Treatment for a Common Female Sexual Disorder,” Marketwatch. 
• H. Ji et al., “The Synthetic Melanocortin (CKPV)2 Exerts Anti-Fungal and Anti-Inflammatory Effects against Candida albicans Vaginitis via Inducing Macrophage M2 Polarization,” PLoS ONE, vol. 8, no. 2, Feb. 2013. 
• V. Maresca, E. Flori, and M. Picardo, “Skin phototype: a new perspective,” Pigment Cell Melanoma Res., vol. 28, no. 4, pp. 376–389, Jul. 2015. 
• L. Feller, R.G. Khammissa, B. Kramer, M. Alini, and J. Lemmer, “Basal cell carcinoma, squamous cell carcinoma and melanoma of the head and face,” Head Face Med., vol. 12, p. 11, Feb. 2016.
• T.R. McMillan, M.A. M. Forster, L.I. Short, A.P. Rudecki, D.L. Cline, and S.L. Gray, “Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice,” Exp. Physiol., vol. 106, no. 2, pp. 427–437, Feb. 2021.  
• C. Spana, R. Jordan, and S. Fischkoff, “Effect of bremelanotide on body weight of obese women: Data from two phase 1 randomized controlled trials,” Diabetes Obes. Metab., vol. 24, no. 6, pp. 1084–1093, Jun. 2022.