Last Updated November 13, 2023

 November 13, 2023

Curious about Melanotan 2 side effects?

Researchers interested in researching Melanotan’s effect on melanin and tanning may be interested in Melanotan 2 side effects.

This guide will outline all the main research findings into this research chemical and explain what researchers must know before working with Melanotan. 

Below, researchers will find a complete guide to Melanotan’s benefits and side effects including how it has been dosed in past studies and trials. To assist researchers interested in experimenting with Melanotan and exploring its side effects, full details of our preferred Melanotan vendor can be found at the end of this guide.

Buy Melanotan 2 from our top-rated vendor...

Disclaimer: contains information about products that are intended for laboratory and research use only, unless otherwise explicitly stated. This information, including any referenced scientific or clinical research, is made available for educational purposes only. Likewise, any published information relative to the dosing and administration of reference materials is made available strictly for reference and shall not be construed to encourage the self-administration or any human use of said reference materials. makes every effort to ensure that any information it shares complies with national and international standards for clinical trial information and is committed to the timely disclosure of the design and results of all interventional clinical studies for innovative treatments publicly available or that may be made available. However, research is not considered conclusive. makes no claims that any products referenced can cure, treat or prevent any conditions, including any conditions referenced on its website or in print materials.

What is Melanotan 2?

Melanotan 2 is a peptide, which is a chemical signaler that is made up of amino acids. It's like a protein, but shorter. Peptides are found naturally throughout the body and work to regulate a number of different bodily functions.

Melanotan 2 is a synthetic peptide that's been created to have the same chemical structure as alpha-melanocyte-stimulating hormone (α-MSH). The α-MSH peptide is produced naturally in the body and secreted from the pituitary gland. It plays a role in regulating a number of bodily functions through melanocortin receptors [1].

One of the functions of α-MSH is to up-regulate the production of melanin by melanocytes in the skin. Melanin is the skin's pigment—it's what determines skin color. It also helps protect the skin against sunlight. When there is more α-MSH in the body's system, there's more melanin, and the result is darker skin that tans more easily [2].

Because Melanotan has the same chemical structure as α-MSH, it has the same effect: binding to melanocortin receptors and increasing skin pigment [3].

That's just one effect. Other types of melanocortin receptors have other effects. For example, Melanotan 2 has been found to also reduce appetite and improve sexual function [1, 3].

There are two types of Melanotan: Melanotan 1 and Melanotan 2. These are often also called Melanotan I and Melanotan II or MT-1 and MT-2 respectively.

In the next section, we’ll explore the benefits of Melanotan 2. 

Melanotan 2 Side Effects

Benefits of Melanotan 2

Researchers interested in the benefits of Melanotan 2 will note that the following effects have been observed in past studies and trials:

  • Tanning and darker skin. Studies have found that Melanotan increases melanin and darkens skin and hair in test subjects [4]. 
  • Reduce sun damage: Research has shown that Melanotan may help protect against sun damage and skin cancer [5, 6].
  • Improved sexual function. There's consistent evidence that Melanotan can improve libido and sexual function in test subjects, including increasing the quality of erections [4, 7, 8, 9].
  • Decreasing appetite. Several animal studies have found that Melanotan injections can reduce appetite and even shift food preferences towards less fatty foods, resulting in significant weight loss [10]. This is consistent with one of the most commonly observed Melanotan side effects: loss of appetite. Some researchers have even suggested that Melanotan dosage has potential as an effective treatment for obesity [11, 12].
  • Regulation of blood sugar. There is research that Melanotan could eventually be used for people with diabetes to regulate blood sugar, although more research is required in this area [13].
  • Improving impulse control. Animal studies have found that Melanotan 2 injections help control impulsive behaviors in rodents [14].
  • Reducing autistic features. Some research has found that Melanotan dosage can reduce features of autism in animal models [15].

Following this brief summary of Melanotan benefits observed in studies, we will turn our attention to Melanotan 2 side effects. 

Melanotan 2 Side Effects | What Researchers MUST Know

Researchers interested in experimenting with Melanotan 2 may be interested to learn about its safety profile. Below is a thorough guide to the side effects observed during past studies.

Just to frame the discussion around Melanotan side effects, it's important to note that most published research indicates that it is generally well-tolerated by test subjects. One review study of several clinical trials concluded that [4],

“Side effects observed in clinical trials [of Melanotan] are largely minor.”

While Melanotan does have side effects, research suggests these side effects are less dangerous than the side effects of tanning using the sun [16], which includes premature aging, wrinkles, and skin cancer.

Common Melanotan 2 Side Effects

The most common Melanotan 2 side effects observed in past studies include [4]:

  • Flushing
  • Nausea
  • Stretching
  • Yawning
  • Increase in libido and erections
  • Decreased appetite
  • Facial hair darkening
  • Patchy pigmentation
  • Pigmentation of the nails
  • Darkening of moles

Less Common Melanotan 2 Side Effects

Some of the less commonly observed Melanotan 2 side effects include:

  • Lethargy
  • Dizziness

Melanotan 1 Side Effects vs. Melanotan 2

Is there a difference between Melanotan 1 side effects compared to the side effects of Melanotan 2?

Yes, there are some slight differences. Research has shown that Melanotan 1 causes fewer side effects when administered to test subjects, compared with Melanotan 2.  

Other Potential Melanotan 2 Side Effects

Some other potential side effects that have been observed during past Melanotan studies include:

  • Pain, itching, and discomfort at the injection site.
  • Bacterial infections (from improperly sterilizing injection equipment before use)

Long-Term Melanotan 2 Side Effects

What about the long-term Melanotan 2 side effects?

Few studies into the long-term side effects of MT-1 or MT-2 exist and little is known about the long-term effects of these research chemicals [4]. Like most drugs, and especially most peptides, research is still in the early phases.

Melanotan 2 and Cancer?

Research involving Melanotan 2 has shown that it increases skin pigment and darkens the skin, potentially darkening the color of moles, but there is no definitive research showing that it contributes to the development of melanoma or skin cancer.

Some research has found that, in test subjects that have presented with melanoma, they have previously been administered Melanotan 2. However, in each of these cases, there was also extensive use of tanning beds, which are known to increase the risk of skin cancer [4].

Other studies have actually found that Melanotan can protect against sun damage and skin cancer. Some research has found that it has an inhibitory effect on the development of skin cancer in vitro [4, 5, 17]. One study concluded that Melanotan 1 has no carcinogenic potential [18].

In conclusion, there is some evidence that Melanotan can be protective against cancer, but its effects aren't entirely known yet.


There is no research showing what dose of Melanotan 2 would be considered an “overdose”. In past studies, most researchers have dosed MT-2 at 500 micrograms (mcg) to 1 mg per test subject. 

Data from these studies indicates that higher doses of Melanotan 2 have been linked with the following side effects:

  • Body aches [19]
  • Sweating [19]
  • Anxiety [19]
  • Agitation [20]
  • High heart rate [20]
  • Palpitations [4]
  • Hyperventilation [4]
  • Abdominal pain [4]
  • Priapism (painful erections) [20]
  • Renal (kidney) disfunction [19]

To date, there are no recorded fatalities associated with Melanotan 2 administration in test subjects [4].

Melanotan Safety

In summary, most research involving Melanotan 2 has concluded that Melanotan is well-tolerated by test subjects and produces few minor side effects [4, 7, 9, 18, 21, 22, 23]. To assist researchers interested in working with Melanotan, details of our preferred vendor will be given in the following section.

Melanotan 2 Side Effects

Where to Buy Melanotan 2 Online? | 2024 Edition

Researchers interested in researching melanotan 2 side effects may be curious about where to buy this research chemical online.

Unfortunately, finding a legitimate supplier of research-grade peptides can be challenging.

After placing small test orders with several leading melanotan 2 vendors, our team has concluded that the following company offers the best service and value for money.


Here are a few specific reasons why we rate PureRawz so highly:

  • 99%+ Pure Peptides: PureRawz posts third-party lab analysis results on their website, allowing researchers to verify the purity of a melanotan 2 product before placing an order.
  • Convenient, Secure Payments: This vendor uses SSL technology to ensure that customer data remains secure, and accepts a range of convenient payment options including credit cards and cryptocurrencies.
  • Quick Shipping: US-based researchers can expect their order to arrive in 2-3 days while internationally-based researchers can expect delivery within 7-21 days. Shipping fees on orders over $100 are waived.
  • Great customer service: PureRawz offers comprehensive customer support via phone, email, and chat to researchers interested in buying peptides online.

Researchers looking to buy melanotan online 2 are advised to visit this top-recommended vendor.

Buy research peptides from Pure Rawz today...

Bacteriostatic Water and Melanotan 2

One of the keys to successful research is having the right toolkit. Particularly when dealing with Melanotan 2, researchers must have a distinct set of tools on hand to facilitate proper storage, reconstitution, and more.

Requisite items like sterile vials and bacteriostatic water may be challenging to collect. The time spent searching for these products may detract from research.

However, they are vital to proper peptide research.

Generally, a researchers' lab may require items like:

  • Bacteriostatic Water
  • Sterile Empty Glass Vials
  • Insulin Syringes
  • Alcohol Prep Pads

If the required supplies are not available, it is recommended to check authorized vendors and sources for the materials.

Side Effects of Melanotan 2 | Verdict

Based on the available research, Melanotan 2 side effects appear to be minor, especially compared to the known side effects of tanning using sunlight or tanning beds, which have been linked to premature aging, wrinkles, and potential skin cancer. However, our review of the evidence has highlighted many areas where a paucity of data exists. 

Researchers interested in exploring Melanotan 2 side effects further are advised to consult the relevant literature regarding the administration of this research chemical. 

Buy Melanotan 2 from our top-rated vendor...


  1. Plant, T. M. & Zeleznik, A. J. (2014). Knobil and Neill's Physiology of Reproduction: Two-Volume Set. Academic Press. pp. 2230–2231.
  2. O’Leary, R. E., Diehl, J., & Levins, P. C. (2014). Update on tanning: More risks, fewer benefits. Journal of the American Academy of Dermatology, 70(3), 562-568.
  3. King, S. H., Mayorov, A. V., Balse-Srinivasan, P., Hruby, V. J., Vanderah, T. W., & Wessells, H. (2007). Melanocortin receptors, melanotropic peptides and penile erection. Current topics in medicinal chemistry, 7(11), 1111-1119.
  4. Brennan, R., Wells, J. G., & Van Hout, M. C. (2014). An unhealthy glow? A review of melanotan use and associated clinical outcomes. Performance Enhancement & Health, 3(2), 78–92.
  5. Barnetson, R. S., Ooi, T. K., Zhuang, L., Halliday, G. M., Reid, C. M., Walker, P. C., … & Kleinig, M. J. (2006). [Nle4-D-Phe7]-α-melanocyte-stimulating hormone significantly increased pigmentation and decreased UV damage in fair-skinned caucasian volunteers. Journal of Investigative Dermatology, 126(8), 1869-1878.
  6. FitzGerald, L. M., Fryer, J. L., Dwyer, T., & Humphrey, S. M. (2006). Effect of MELANOTAN®, [Nle4, D-Phe7]-α-MSH, on melanin synthesis in humans with MC1R variant alleles. Peptides, 27(2), 388-394.
  7. Wessells, H., Fuciarelli, K., Hansen, J., Hadley, M. E., Hruby, V. J., Dorr, R., & Levine, N. (1998). Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. The Journal of Urology, 160(2), 389-393.
  8. Hakim, L. S. (1998). Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: Double-blind placebo controlled crossover study. International Journal of Impotence Research, 10(4), 263-263.
  9. Wessells, H., Levine, N., Hadley, M. E., Dorr, R., & Hruby, V. (2000). Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II. International journal of impotence research, 12(4), S74-S79.
  10. van der Klaauw, A., Keogh, J., Henning, E., Stephenson, C., Trowse, V. M., Fletcher, P., & Farooqi, S. (2015). Role of melanocortin signalling in the preference for dietary macronutrients in human beings. The Lancet, 385, S12.
  11. Lee, Y. S. (2009). The role of leptin-melanocortin system and human weight regulation: lessons from experiments of nature. Annals Academy of Medicine Singapore, 38(1), 34.
  12. Bjørbæk, C., & Hollenberg, A. N. (2002). Leptin and melanocortin signaling in the hypothalamus. Vitamins and Hormones, 65, 281-311.
  13. Guo, F., Bakal, K., Minokoshi, Y., & Hollenberg, A. N. (2004). Leptin signaling targets the thyrotropin-releasing hormone gene promoter in vivo. Endocrinology, 145(5), 2221-2227.
  14. York, D. A., Boghossian, S., & Park-York, M. (2011). Melanocortin activity in the amygdala influences alcohol intake. Pharmacology Biochemistry and Behavior, 98(1), 112-119.
  15. Minakova, E., Lang, J., Medel-Matus, J. S., Gould, G. G., Reynolds, A., Shin, D., … & Sankar, R. (2019). Melanotan-II reverses autistic features in a maternal immune activation mouse model of autism. PloS one, 14(1), e0210389.
  16. Levine, N., Sheftel, S. N., Eytan, T., Dorr, R. T., Hadley, M. E., Weinrach, J. C., … & Hruby, V. (1991). Induction of skin tanning by subcutaneous administration of a potent synthetic melanotropin. JAMA, 266(19), 2730-2736.
  17. Jiang, J., Sharma, S. D., Nakamura, S., LAI, J. Y., Fink, J. L., Hruby, V. J., & Hadley, M. E. (1995). The Melanotropic Peptide,[Nle4, d‐Phe7] α‐MSH, Stimulates Human Melanoma Tyrosinase Activity and Inhibits Cell Proliferation. Pigment Cell Research, 8(6), 314-323.
  18. Hadley, M. E., & Dorr, R. T. (2006). Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides, 27(4), 921-930.
  19. Nelson, M. E., Bryant, S. M., & Aks, S. E. (2012). Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. Clinical Toxicology, 50(10), 1169-1173.
  20. Devlin, J., Pomerleau, A., & Foote, J. (2013). Melanotan II overdose associated with priapism. Clinical Toxicology, 51(4), 383.
  21. Ugwu, S. O., Blanchard, J., Dorr, R. T., Levine, N., Brooks, C., Hadley, M. E., … & Hruby, V. J. (1997). Skin pigmentation and pharmacokinetics of Melanotan‐I in humans. Biopharmaceutics & drug disposition, 18(3), 259-269.
  22. Dorr, R. T., Lines, R., Levine, N., Brooks, C., Xiang, L., Hruby, V. J., & Hadley, M. E. (1996). Evaluation of Melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sciences, 58(20), 1777-1784.
  23. Dorr, R. T., Ertl, G., Levine, N., Brooks, C., Bangert, J. L., Powell, M. B., … & Alberts, D. S. (2004). Effects of a superpotent melanotropic peptide in combination with solar UV radiation on tanning of the skin in human volunteers. Archives of dermatology, 140(7), 827-835.

Scientifically Fact Checked by:

David Warmflash, M.D.

Table of Contents
    Add a header to begin generating the table of contents