Product Description
Peptide buccal strips for in vitro research applications, each containing PT-141 (1 mg) and Oxytocin (25 mcg).
PT-141, also known as bremelanotide, is a synthetic peptide that mimics the structure of alpha-melanocyte-stimulating hormone (α-MSH). It functions as a melanocortin receptor agonist, meaning it binds to and activates specific melanocortin receptors, primarily the MC3 and MC4 receptors. These receptors are part of a family of proteins involved in regulating various physiological processes, such as sexual function and appetite control.
Oxytocin is a peptide hormone, specifically a nonapeptide, meaning it is composed of nine amino acids. Its chemical structure is characterized by the sequence Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2. This hormone is produced in the hypothalamus, a region of the brain, and is released by the posterior pituitary gland, an endocrine structure involved in hormone secretion.
Peptide Specifications
| Property | PT-141 | Oxytocin |
|---|---|---|
| Peptide Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH | Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH₂ |
| Molecular Formula | C50H68N14O10 | C43H66N12O12S2 |
| Molecular Weight | 1025.2 g/mol | 1007.2 g/mol |
| CAS Number | 1607799-13-2 | 50-56-6 |
| PubChem CID | 9941379 |
439302
|
Research Overview
The research on PT-141 (bremelanotide) demonstrates a clear mechanistic rationale for research into sexual dysfunction, with robust preclinical and clinical evidence supporting its efficacy in increasing sexual desire and arousal, particularly in premenopausal women with HSDD.
Oxytocin demonstrates correlations with sexual arousal, orgasm, and social bonding, with clear evidence of increased levels during activity.
Mechanisms of Action
PT-141 is a synthetic analogue of α-melanocyte-stimulating hormone (α-MSH) and acts as an agonist at melanocortin receptors, especially MC3R and MC4R, which are predominantly expressed in the central nervous system. Activation of these receptors in the hypothalamus, particularly the medial preoptic area (mPOA), is thought to increase dopamine release in research models[1].
Oxytocin acts via the oxytocin receptor (OXTR), a G protein-coupled receptor, triggering signaling cascades (MAPK, PKC, PLC, CaMK) that affect neuronal activity, neurotransmitter release, and gene expression. Beyond the brain, oxytocin impacts the cardiovascular, gastrointestinal, immune, and metabolic systems[2].
PT-141 in Sexual Dysfunction Research
Bremelanotide has been evaluated in multiple phase II and III clinical trials investigating HSDD in premenopausal women and erectile dysfunction in men.
In women, bremelanotide demonstrated measurable effects on sexual desire and distress metrics associated with low desire, with effects observed across various subgroups (age, BMI, hormonal contraceptive use)[3].
In men, PT-141 induced dose-dependent increases in erectile activity, including in those with erectile dysfunction previously unresponsive to other interventions[4].
Preclinical Applications of PT-141
Beyond sexual dysfunction, the melanocortin system is being explored as a research target for metabolic disorders such as obesity and cachexia, with bremelanotide and related agents demonstrating activity in preclinical models[5].
Recent studies have also investigated bremelanotide’s effects in oncology, specifically glioblastoma, where it induces cell death via MC3R/MC4R-mediated pathways[6].
Oxytocin and Sexual Desire Research
Oxytocin is released during sexual arousal and orgasm in both men and women, suggesting a role in reproductive behaviors and physiological responses[7].
In animal studies, oxytocin acts in the brain and spinal cord to influence erectile function and sexual activity, often working alongside other neurotransmitters[8].
The hormone’s effects are modulated by sex hormones (estrogen, progesterone, testosterone), which may explain differences in physiological response and the variability of oxytocin’s effects between sexes[9].
References
- Pfaus, J., Sadiq, A., Spana, C., & Clayton, A. The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women. CNS Spectrums.2021; 27. https://doi.org/10.1017/S109285292100002X.
- Ueda, Y. Oxytocin: An expansive review of its mechanisms, functions, and therapeutic potential. World Journal of Advanced Research and Reviews.2023 https://doi.org/10.30574/wjarr.2023.19.1.1499.
- Mayer, D., & Lynch, S. Bremelanotide: New Drug Approved for Treating Hypoactive Sexual Desire Disorder. Annals of Pharmacotherapy.2020; 54. https://doi.org/10.1177/1060028019899152.
- Molinoff, P., Shadiack, A., Earle, D., Diamond, L., & Quon, C. PT‐141: A Melanocortin Agonist for the Treatment of Sexual Dysfunction. Annals of the New York Academy of Sciences.2003; 994. https://doi.org/10.1111/j.1749-6632.2003.tb03167.x.
- Sweeney, P., Gimenez, L., Hernandez, C., & Cone, R. Targeting the central melanocortin system for the treatment of metabolic disorders. Nature Reviews Endocrinology.2023; 19. https://doi.org/10.1038/s41574-023-00855-y.
- Suzuki, S., Kitanaka, C., & Okada, M. Melanocortin Receptor Agonist Bremelanotide Induces Cell Death and Growth Inhibition in Glioblastoma Cells via Suppression of Survivin Expression. AntiCancer Research.2024; 44. https://doi.org/10.21873/anticanres.17214.
- Carmichael, M., Humbert, R., Dixen, J., Palmisano, G., Greenleaf, W., & Davidson, J. Plasma oxytocin increases in the human sexual response.. The Journal of clinical endocrinology and metabolism.1987; 64 1. https://doi.org/10.1210/JCEM-64-1-27.
- Melis, M., & Argiolas, A. Oxytocin, Erectile Function and Sexual Behavior: Last Discoveries and Possible Advances. International Journal of Molecular Sciences.2021; 22. https://doi.org/10.3390/ijms221910376.
- Quintana, D., Glaser, B., Kang, H., Kildal, E., Audunsdottir, K., Sartorius, A., & Barth, C. The interplay of oxytocin and sex hormones. Neuroscience & Biobehavioral Reviews.2024; 163. https://doi.org/10.1016/j.neubiorev.2024.105765.
