PT-141 (Bremelanotide) Dosage

PT-141 is a synthetic peptide designed to enhance libido and participate in treating various forms of sexual dysfunctions. It is also known as Bremelanotide, and the origin of the name is explained by the fact that its primary mechanism of action involves the activation of Melanocortin receptors. The results of scientific studies indicate that PT-141 achieves equally good results in treating sexual dysfunctions in both sexes, some of the most common being erectile dysfunction in men and hypoactive sexual desire in women. Additionally to achieving long-lasting effects fairly quickly from the start of administration, this peptide can improve sexual satisfaction, boost self-confidence, and reduce symptoms of anxiety related to sexual intercourse.

Dosage Chart

About the Peptide

PT-141 - Bremelanotide is a synthetic peptide primarily used to treat sexual dysfunction in men and women. Unlike other similar compounds, the mechanism of action of this peptide is not based on the modulation of vascular permeability but instead on direct stimulation of the part of the central nervous system responsible for sexual desire and reaction to sexual stimuli.

Scientists assume that this peptide primarily binds to Melanocortin receptors (especially MC4R), further activating them. After binding, many substances are released in large amounts, which is responsible for increasing sexual desire, such as Domanin. These substances are typically produced during sexual intercourse and lead to ejaculation in men, so the system of treating dysfunction is mainly based on potentiating vital release.

One of the primary sexual drive disorders in men is erectile dysfunction. It is characterized by difficulty achieving an erection, as well as the inability to maintain it for a long time. This is a relatively common diagnosis, and causes vary. They can be psychogenic or somatic when it often appears as a symptom of severe diseases. PDE5 inhibitors (inhibit the enzyme phosphodiesterase type 5) are frequently the first-choice therapy for such patients. However, patients usually do not respond to this treatment. As it works by regulating blood flow through the blood vessels, patients with cardiovascular diseases or diabetes mellitus can’t use the drug. That is why PT-141 has proven to be particularly potent, as it acts directly on the central nervous system. The results have been confirmed in practical terms through clinical studies when most patients reported improvement in symptoms, regular achievement of erections, and maintenance. In addition to these effects, men felt more confident during intercourse, with a complete absence of fear.

When it comes to women, hypoactive sexual desire is the most common sexual desire disorder. It is characterized by the absence of spontaneous sexual thoughts, a lack of desire for intimate relationships, and the inability to enjoy them. The reasons vary and can be psychological, somatic, or the result of long-term therapy. However, this kind of problem can cause issues in the relationship, mainly when it occurs in young women. It was found that with a similar mechanism of action, PT-141 can cause significant improvement by increasing sexual desire and enabling the enjoyment of intercourse. Patients reported an easier onset and normal course of the intimate act after therapy.

List of Uses

Treating Erectile Dysfunction

Erectile dysfunction is a form of penile dysfunction when a man has trouble achieving or maintaining an erection. In such cases, intercourse ends very quickly, and the patient feels insecure and embarrassed. The etiological reasons for the occurrence of this condition are numerous and can be psychological when the patient feels anxious or depressed. Stress also makes it impossible to maintain an erection because, in such situations, large amounts of adrenaline are secreted, which increases the pressure in the body. Therefore, impotence can be a consequence of the consumption of certain medications such as antidepressants (especially if the therapy lasts longer), sedatives, diuretics, antihypertensives, or muscle relaxants. If the patient uses alcohol or substances such as marijuana, methadone, cocaine, and other opioids, erectile dysfunction can also occur as a result. We should not forget that impotence can be a symptom of more serious diseases such as diabetes mellitus, vascular diseases, kidney diseases, or hormonal disorders.

The most commonly used therapy so far is the PDE5 inhibitors, which inhibit the enzyme phosphodiesterase type 5, reducing the level of cyclic guanosine monophosphate. When this is inhibited, cGMP concentrations increase, which leads to increased flow through the blood vessels of the penis and makes it easier to achieve an erection. However, many patients did not respond to this therapy. In addition, conditions from the cardiovascular disease group represent a direct contraindication, as this therapy works by regulating blood flow.

On the other hand, PT-141 acts directly on the central nervous system, binding to Melanocortin receptors (primarily MC4R), which are located near the hypothalamic and limbic regions responsible for perceiving sexual desire. The peptide can also potentially stimulate the production of α-Melanocyte-stimulating hormone (α-MSH), which also binds to MC4R receptors and exerts beneficial effects, including increased sexual desire.

As a result of this mechanism of action, patients in scientific studies have reported mostly beneficial effects. After the therapy, they began to feel a surge in sexual desire, easy erection achievement, and retention. In addition, they were freed from feelings of fear and shame and continued to function much better than before therapy with this peptide.

Treating Hypoactive Sexual Desire Disorder in Women (HSDD)

This form of sexual disorder in women is characterized by decreased sexual desire, spontaneous sexual thoughts, actions, or fantasies. A common cause of this condition can be the side effects of certain medications, such as antidepressants or antihypertensives, which can have a significant impact on sex drive in women. However, the reason can also be medical, such as in patients diagnosed with neurological disorders, hormonal dysregulation, nervous diseases, hypertension, or hyperthyroidism. After childbirth, during breastfeeding, or in states of stress and depression, women often have no desire for sexual intercourse. However, six months of symptomatology must pass before a diagnosis can be made.

Through numerous studies, PT-141 has emerged as a possible therapeutic option, as it acts directly on the central nervous system and is responsible for the perception of feelings and sexual desire. Using the exact mechanisms of action, binding to MC4R receptors in the brain and boosting the production of the α-MSH hormone, the peptide achieves beneficial results such as increased sexual desire, reduced feelings of anxiety and fear, increased self-confidence, and restored normal daily activities. Participants in scientific studies who suffer from this disorder generally reported an improvement in their condition, a return of sexual desire, spontaneous sexual thoughts, and reduced feelings of anxiety when initiating sexual intercourse.

Dosing Calculator

Dosage always depends on the indication, although in this case, PT-141  Bremelanotide is most often used to treat sexual dysfunction in men and women. The optimal dose is usually 0.5 mg per day, administered as a single subcutaneous injection. However, doctors typically recommend a dose of 1.25 mg to 1.5 mg spread over two to three days. The amount of active substance is the same in both cases. However, when the dose is spread out, the effect of the peptide is enhanced, allowing the body more time for the adaptation period.

After a specific period, the dose can be slightly increased to 1 mg per day or 2 mg distributed over two to three days. The method of administration remains the same (subcutaneous injection), and the injection site is most often the abdomen. The mentioned dose must never be exceeded or adjusted independently, as severe side effects may occur otherwise.

Conclusion

PT-141 is a synthetic peptide known for its beneficial effects in treating sexual dysfunction disorders in men and women. Based on clinical studies, it has been determined that if used in the optimal dose, it can be a crucial part of the therapy of erectile dysfunction and hypoactive sexual desire disorder in women. Regardless of the achievements so far, PT-141 will undoubtedly remain a subject of future research.

References:

1. Molinoff, P. B., Shadiack, A. M., Earle, D., Diamond, L. E., & Quon, C. Y. (2003). PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Annals of the New York Academy of Sciences, 994, 96–102. https://doi.org/10.1111/j.1749-6632.2003.tb03167.x
2. Pfaus, J., Giuliano, F., & Gelez, H. (2007). Bremelanotide: an overview of preclinical CNS effects on female sexual function. The journal of sexual medicine, 4 Suppl 4, 269–279. https://doi.org/10.1111/j.1743-6109.2007.00610.x
3. Vemulapalli, R., Kurowski, S., Salisbury, B., Parker, E., & Davis, H. (2001). Activation of central melanocortin receptors by MT-II increases cavernosal pressure in rabbits by the neuronal release of NO. British journal of pharmacology, 134(8), 1705–1710. https://doi.org/10.1038/sj.bjp.0704437
4. Thurston, L., Hunjan, T., Mills, E. G., Wall, M. B., Ertl, N., Phylactou, M., Muzi, B., Patel, B., Alexander, E. C., Suladze, S., Modi, M., Eng, P. C., Bassett, P. A., Abbara, A., Goldmeier, D., Comninos, A. N., & Dhillo, W. S. (2022). Melanocortin 4 receptor agonism enhances sexual brain processing in women with hypoactive sexual desire disorder. The Journal of clinical investigation, 132(19), e152341. https://doi.org/10.1172/JCI152341
5. Clayton AH, Althof SE, Kingsberg S, DeRogatis LR, Kroll R, Goldstein I, Kaminetsky J, Spana C, Lucas J, Jordan R, Portman DJ. Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. Womens Health (Lond). 2016 Jun;12(3):325-37. doi: 10.2217/whe-2016-0018. Epub 2016 May 16. PMID: 27181790; PMCID: PMC5384512.
6. James Pfaus, François Giuliano, Hélène Gelez, Bremelanotide: An Overview of Preclinical CNS Effects on Female Sexual Function, The Journal of Sexual Medicine, Volume 4, Issue Supplement_4, November 2007, Pages 269–279, https://doi.org/10.1111/j.1743-6109.2007.00610.x
7. McMillan TR, Forster MAM, Short LI, Rudecki AP, Cline DL, Gray SL. Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice. Exp Physiol. 2021 Feb;106(2):427-437. doi: 10.1113/EP088838. Epub 2020 Dec 17. PMID: 33332767.