Understanding Peptides Melanotan 2 and Bremelanotide

Peptides refer to short chains of amino acids linked together by peptide bonds – they’re similar to proteins, but proteins have long amino acid chains. Peptides occur naturally in all living creatures – humans, animals, plants, and fungi – and they perform numerous vital functions . 

Peptides can be synthetically created to mimic the actions of natural peptides. Synthetic peptides cannot survive the digestive process; therefore, they’re combined with a sterile solvent and injected into subjects. 

The FDA has not approved peptides like Melanotan II and PT 141 for use as therapeutic or dietary supplements. They are, however, approved as investigational compounds and can be legally used by researchers for this reason.

What Is Melanotan 2?

Melanotan 2 (MT-2) or sometimes written as Melanotan II is a synthetic form of human α melanocyte stimulating hormone (α MSH). This neuropeptide hormone stimulates skin pigmentation and performs other functions critical to health, such as regulating inflammation, reproduction, and metabolism. Melanotan 2 mimics the actions of α MSH and is being studied to see if the same effects are reproducible.

What Is Bremelanotide? 

Bremelanotide, or PT 141 peptide, is a synthetic melanocortin based peptide that activates the Melanocortin 4 receptor (MC-4R). This receptor is primarily located in the central nervous system and has been linked to sexual function. Bremelanotide mimics the action of this receptor.

Melanocortin

In this study, the researchers investigated the impact of Melanotan II (MTII), a melanocortin analog, on sexual function in both male and females. Melanocortins (MCs) are peptide hormones known for their diverse physiological functions. Previous studies have suggested their involvement in assisting sexual dysfunction in animals.

The results revealed that MTII administration yielded positive effects on sexual function. In males, improved erectile dysfunction, while in females, it increased levels of sexual interest and genital arousal. Notably, unlike other compounds used for sexual enhancement, MTII exerted its effects at the brain level. This mechanism resulted in a more natural sexual response with minimal or no undesirable side effects.

Interestingly, the discovery of MTII’s sexual-enhancement properties was accidental, as the initial focus of the research was on investigating the effects of the peptide and its analogs on human skin pigmentation, particularly tanning. This unexpected finding highlights the multifunctional nature of MCs and their potential for modulating various physiological processes beyond their primary target.

Melanotan 2 and PT 141 Research

Researchers have only begun to explore the potential of Melanotan 2 and PT 141, and most of the available evidence is pre-clinical. Here are five promising areas that can be explored. 

1. Melanogenesis (Skin Tanning) 

Melanotan 2 has shown potential in stimulating skin tanning, or melanogenesis. Melanotan binds to melanocortin receptors (MC-1R and MC-4R), which are found in melanocytes, the cells that are involved in the production of melanin, which is responsible for the darkening of the skin. More clinical trials must be conducted to confirm this finding.

2. Erectile Dysfunction /Libido

Melanotan 2 and PT 141 have demonstrated efficacy in the treatment of erectile dysfunction and poor libido in both males and female test subjects. One study demonstrated the efficacy of Melanotan in 80% of cases that had failed to respond to other treatments in assisting sexual dysfunction.

Studies in mice have shown that bremelanotide causes sexual arousal in both males and females by binding to MC-4R. In recent clinical trials of male subjects, Bremelanotide treated erectile dysfunction in one-third of the subjects, even when they had not responded to other forms of treatment. Bremelanotide is of interest to researchers as a potential solution for treating sexual dysfunction. 

PT 141 and Melanotan 2 work on the nervous system, which means they may be able to treat sexual disorders that are not triggered by the restriction of blood flow to the genitals.

3. Addiction

MT-2 has been implicated in oxytocin signaling and hence impulse control. Clinical studies in mice have demonstrated that the administration of MT-2 reduced alcohol intake and triggered an increase in water intake. Other studies have shown that MT-2 works in synergy with Naltrexone – a compound used to manage opioid and alcohol addiction.

4. Autism and Alzheimer’s

Melanotan 2 peptides have been shown to minimize the accumulation of beta-amyloid and reduce the A1 subtype of reactive astrocytes, factors that have been linked to the cause of Alzheimer’s disease. The alpha melanocyte stimulating hormone mimetic MT-2 has also been shown to increase oxytocin receptor expression and signaling and hence reduce repetitive behaviors associated with ASD.

5. Satiety and Weight Loss

Animal studies have demonstrated PT-141’s ability to increase energy expenditure and improve resting metabolism by activating the MC-4R receptor.

6. Insulin

In clinical studies conducted on Otsuka Long-Evans Tokushima Fatty (OLETF) male rats and female rats, the researchers examined the effects of melanotan II (MTII), a melanocortin agonist, on insulin sensitivity and glucose tolerance following peripheral administration. The OLETF rats were subjected to subcutaneous administration of MTII via osmotic mini-pumps, resulting in a decrease in their food intake and body weight.

During the insulin tolerance tests conducted on day 9, the MTII group exhibited greater sensitivity to insulin compared to both the group allowed to eat ad libitum and the pair-fed group. Furthermore, during the glucose tolerance tests conducted on days 11 and 23, the MTII group demonstrated significantly lower glucose values in comparison to the ad libitum group. These findings indicate that MTII administration enhanced insulin sensitivity and improved glucose tolerance in the OLETF rats.

Adverse Effects

Effects related to blood pressure and other heart and vascular system-related issues were not discussed in the above articles. More research needs to be conducted on PT 141 and Melanotan 2 to ensure the side effects are well studied. More testing on nervous system involvement should be completed as well to gain a better understanding of how sexual desire and sexual dysfunction are changed with the incorporation of these chemical compounds.

Pitfalls to Avoid 

You can legally purchase peptides online for investigational purposes in the U.S. It is, however, very easy to get duped into buying inferior products or even those that lack an active ingredient. Use these tips to keep you safe when purchasing peptides.

Avoid Cheap Peptides

Everyone likes a good bargain, but saving a few bucks now can be costly in the long term. Quality peptides are expensive to produce, so take note when the price seems too good to be true.

Reputable peptide vendors will always subject their products to third-party testing by an independent laboratory. This shows a commitment to quality, and it’s also a mark of transparency.  

Remember that peptides are only legal for investigational purposes and are therefore not FDA-approved as drugs or supplements. 

Melanotan 2 and PT 141 have shown significant potential. Skin tanning, sexual performance, impulse control, neurological function, and weight loss are areas of particular interest to researchers.