PT-141 10mg

PT-141, known as bremelanotide, has earned the nickname “female Viagra” due to its involvement in phase IIb human clinical trials aimed at treating female hypoactive sexual desire disorder (HSDD). This melanocortin peptide primarily binds to melanocortin 4 receptor (MC-4R) and MC-1R. Additionally, in 2009, PT-141 was explored as a potential treatment for acute hemorrhage. Notably, PT-141 is a derivative of another synthetic melanocortin, melanotan 2 (MT-2).

Source: PubChem

Sequence: Ac-Nle-Asp(1)-His-D-Phe-Arg-Trp-Lys(1)
Molecular Formula: C₅₀H₆₈N₁₄O₁₀
Molecular Weight: 1025.182 g/mol
PubChem CID: 9941379
CAS Number: 189691-06-3

PT-141 and Sexual Arousal

PT-141 stands out as a unique peptide due to its stimulation of the MC-4R, a receptor known for triggering sexual arousal in the central nervous system and influencing sexual behavior [1], [2]. Mice studies have demonstrated that binding to the MC-4R through an agonist induces sexual arousal and heightened copulation in both male and female subjects [3], [4]. Notably, PT-141 operates via a distinct mechanism from drugs like Viagra, making it a potential treatment for sexual arousal disorders in both men and women, even those not stemming from reduced blood flow to the genitals.

In a study involving men with erectile dysfunction (ED) who failed to respond to sildenafil (Viagra), approximately one-third of the participants achieved sufficient erections for sexual intercourse with PT-141 administered via nasal spray. Additionally, the trial displayed a robust dose-dependent response, indicating the effectiveness of PT-141 in certain cases[]. These findings suggest that PT-141 may hold promise in addressing ED in situations where sildenafil has proven ineffective and could provide valuable insights into understanding the central causes of hypoactive sexual desire.

Duration of penile base rigidity greater than 60% for placebo compared to various doses of PT-141.
Source: Nature

PT-141, a drug with potential for treating women suffering from HSDD, was intriguingly withdrawn from clinical trials before receiving approval. Despite demonstrating a statistically significant increase in the number of satisfying sexual events per month and a decrease in female sexual distress scores without significant side effects[6], it did not progress for use in this condition. Many experts treating female sexual dysfunction (FSD) were disappointed by this decision, attributing it to the absence of established endpoints for FSD trials and socio-cultural biases against women’s sexual health. These hurdles hinder the approval of much-needed therapies like PT-141[7].

These experts advocate for increased attention to the topic and the establishment of more concrete guidelines by the FDA to evaluate beneficial therapies like PT-141. They also express regret that pharmacological treatments were not tested alongside other established means of treating sexual dysfunction, believing that combining therapies may prove synergistic. Additionally, they view peptides like PT-141 as valuable for overcoming initial barriers and initiating psychological treatment modalities.

In response to the outcry against earlier trials’ cessation, Phase II Reconnect trials using subcutaneous injections of PT-141 for FSD were launched in 2017. The latest version of PT-141, known as Rekynda, is expected to soon be available for use in the United States. This would permit off-label use of PT-141 to treat both male and female sexual dysfunction[8]. The new trials have incorporated modified endpoints, a move welcomed by experts in FSD, as it enhances the chances of approval for such treatments.

PT-141 and Hemorrhage

In 2009, PT-141 underwent slight modifications and was studied as a potential treatment for hemorrhagic shock. Given its binding affinity to both MC-1R and MC-4R, PT-141 demonstrated the ability to mitigate ischemia and safeguard tissues from inadequate blood supply in cases of hypovolemic (hemorrhagic) shock. Intravenous administration of the drug resulted in minimal side effects. The modified variant of PT-141 is now recognized as PL-6983 and has been evaluated in phase IIb trials.

PT-141 and Infection

In a rat model of a specific fungal infection, the MC-1R has been discovered to exhibit significant anti-fungal and anti-inflammatory properties[9]. This finding holds particular significance as existing anti-fungal treatments have limitations in their mechanism of action and often lead to severe and treatment-restricting side effects in certain individuals. The identification of an alternative approach for treating fungal infections could have a profound impact, reducing both morbidity and mortality rates, especially among patients with compromised immune systems.

PT-141 and Cancer

The MC-1R receptor plays a crucial role in stimulating DNA repair pathways, making it a significant point of interest in cancer treatment and prevention[10]. Studies indicate that individuals with variants of MC-1R face an elevated risk for basal cell and squamous cell carcinoma[11]. Modified PT-141 shows promise in potentially addressing the issues arising from these variants, offering potential avenues for preventing or treating these types of cancers.

Currently, PT-141 has garnered considerable attention as a treatment for sexual dysfunction. However, its potential extends beyond addressing sexual issues and hemorrhage, offering opportunities for diverse research applications. For instance, MC-4R, a target of PT-141, is associated with certain cases of obesity, potentially contributing to up to 6% of early-onset obesity cases. Exploring PT-141’s impact on this specific cause of obesity may unveil intervention pathways. Additionally, MC-1R, another receptor affected by PT-141, plays roles in pain, inflammation, kidney pathology, and infection spread, presenting various research avenues.

It’s crucial to note that PT-141 exhibits minimal side effects and displays excellent bioavailability when administered subcutaneously in mice. However, dosage considerations must be adjusted from mice to humans. PT-141 available at Peptide Sciences is solely intended for educational and scientific research purposes and is not suitable for human consumption. Purchases should only be made by licensed researchers.

The above literature was researched, edited and organized by Dr. Logan, M.D. Dr. Logan holds a doctorate degree from Case Western Reserve University School of Medicine and a B.S. in molecular biology.

Dr. Sheryl A. Kingsberg is the chief of behavioral medicine at University Hospitals Case Medical Center and professor in Reproductive Biology and Psychiatry at Case Western Reserve University. Her areas of clinical specialization include sexual medicine, female sexual disorders, cognitive behavioral psychotherapy, menopause, pregnancy and postpartum mood disorders, psychological aspects of infertility, and psychological and sexual aspects of cancer. Dr. Kingsberg’s primary research interests are in treatments for female sexual disorders and the psychological aspects of infertility and menopause.

She led a randomized, placebo-controlled dose-finding trial for PT-141. She has numerous publications in many national and international journals, sits on the editorial board of Menopause and has authored numerous chapters on topics including perimenopause and sexuality, oocyte donation, infertility and aging, the treatment of psychogenic erectile dysfunction and sexuality after cancer.

Dr. Kingsberg received her PhD from the University of South Florida in Tampa and completed her fellowship in sexual medicine at University Hospitals Case Medical Center. She is an active member in a number of national and international organizations including the American Psychological Association and the American Society for Reproductive Medicine. She currently sits on the Board of Trustees of The North American Menopause Society, and serves as the current treasurer of the Society for Assisted Reproductive Technologies. Dr. Kingsberg s a past president of The International Society for the Study of Women’s Sexual Health.

Dr. Sheryl A. Kingsberg is being referenced as one of the leading scientists involved in the research and development of PT-141. In no way is this doctor/scientist endorsing or advocating the purchase, sale, or use of this product for any reason. There is no affiliation or relationship, implied or otherwise, between Peptide Sciences and this doctor. The purpose of citing the doctor is to acknowledge, recognize, and credit the exhaustive research and development efforts conducted by the scientists studying this peptide. Dr. Kingsberg is listed in [12] under the referenced citations.

1. M. Sandrock, A. Schulz, C. Merkwitz, T. Schöneberg, K. Spanel-Borowski, and A. Ricken, “Reduction in corpora lutea number in obese melanocortin-4-receptor-deficient mice,” Reprod. Biol. Endocrinol. RBE, vol. 7, p. 24, Mar. 2009.
2. R. C. Rosen, L. E. Diamond, D. C. Earle, A. M. Shadiack, and P. B. Molinoff, “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. [PubMed]
3. H. Wessells, 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. [PubMed]
4. A.-S. Rössler, J. G. Pfaus, H. K. Kia, J. Bernabé, 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. [PubMed]
5. 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. [PubMed]
6. 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. [PubMed]
7. 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. [PubMed]
8. “AMAG Pharmaceuticals and Palatin Technologies Enter Into Exclusive Licensing Agreement for North American Rights to RekyndaTM (bremelanotide), a Potential Treatment for a Common Female Sexual Disorder – AMAG Pharmaceuticals.” . [MarketWatch]
9. 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. [PLOS ONE]
10. V. Maresca, E. Flori, and M. Picardo, “Skin phototype: a new perspective,” Pigment Cell Melanoma Res., vol. 28, no. 4, pp. 378–389, Jul. 2015. [PubMed]
11. L. Feller, R. a. G. Khammissa, B. Kramer, M. Altini, 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. [PubMed]
12. Clayton AH, Althof SE, Kingsberg S, et al. Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. Womens Health (Lond). 2016;12(3):325–337. doi:10.2217/whe-2016-0018
13. 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, doi: 10.1113/EP088838.”
14. 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, doi: 10.1111/dom.14672. ”

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The products offered on this website are furnished for in-vitro studies only. In-vitro studies (Latin: in glass) are performed outside of the body.  These products are not medicines or drugs and have not been approved by the FDA to prevent, treat or cure any medical condition, ailment or disease.  Bodily introduction of any kind into humans or animals is strictly forbidden by law.