Last Updated March 19, 2024

 March 19, 2024

Peptide researchers looking to explore the similarities and differences between melanotan 1 vs. melanotan 2 have come to just the right place.

This comprehensive overview compares the two peptides, providing insights into their benefits, side effects, and applications.

Our expert team also provide details on the potential of melanotan 1 and melanotan 2 for uses like:

  • enhancing skin pigmentation and UV tolerance
  • boosting libido and sexual function
  • suppressing appetite and stimulating weight loss
  • Keep reading as we provide the most up-to-date clinical and preclinical data on these two compounds, before recommeding a reliable source for procuring high-quality melanotan 1 and melanotan 2 for research purposes.

Buy Melanotan 1 from our top-rated vendor...

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What is Melanotan 1?

Melanotan 1 (MT1), also known as [Nle4, D-Phe7]-alpha-MSH or afamelanotide (CUV1647), is a synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH) [1].

Alpha-MSH is an endogenous 13 amino acid peptide that plays a pivotal role in regulating melanin synthesis, sexual desire, energy balance, and appetite. These functions are primarily mediated through the melanocortin receptors (MCRs) in various tissues [2].

The structure of MT1 closely resembles that of endogenous alpha-MSH. Here are some more specifics [3]:

  • MT1 comprises a linear chain of 13 amino acids.
  • Notable modifications of MT1 over alpha-MSH include the substitution of methionine and L-phenylalanine at the fourth and seventh positions with norleucine and D-phenylalanine, respectively.
  • MT1 has enhanced half-life and increased affinity for the melanocortin receptor 1 (MC1R), which regulates melanogenesis.

As an MC1R agonist, MT1 facilitates melanin production, leading to a darker skin tone with repeated administration.

Initially developed as a sunless tanning and photoprotective agent, MT1 has shown promise in therapeutic areas such as in treating acute photodermatoses, including erythropoietic protoporphyria and polymorphic light eruption.

In October 2019, the United States Food and Drug Administration (FDA) approved MT1 under the brand name Scenesse for increasing sunlight tolerance and alleviating pain from ultraviolet (UV) light exposure in patients with erythropoietic protoporphyria (EPP) [4].

EPP is caused by enzyme deficiency, leading to a buildup of protoporphyrin IX in the skin and blood. Protoporphyrin IX can absorb UV light to create reactive oxygen species that damage skin and cause pain and scarring.

Scenesse is administered to EPP patients as subcutaneous implants, offering improved pharmacokinetics compared to regular injections.

In addition, MT1 is also available as a research peptide for scientific and educational purposes. In this manner, it is typically shipped in dry powder form for reconstitution and subcutaneous administration.


Melanotan 1 vs Melanotan 2


What is Melanotan 2?

Melanotan 2 (MT2) is another synthetic analog of alpha-MSH, but it differs significantly from MT1 and alpha-MSH in terms of structure [5]:

  • MT2 is a cyclic peptide consisting of seven amino acids, forming a ring due to a lactam bridge established through a linkage between the side-chain carboxyl group of aspartic acid at the second position and the side-chain amino group of the lysine residue at the seventh position.
  • Compared to MT1 and alpha-MSH, the cyclic form of MT2 boosts affinity towards various melanocortin receptors, namely MC1R and MC4R.
  • The enhanced affinity of MT2 to different receptors results in a wider range of potential benefits and side effects.

By targeting MC1R and MC4R, MT2 regulates melanogenesis and sexual behavior, respectively. It also interacts with MC3R, which is linked to metabolic regulation [6].

Originally developed as a tanning agent, ongoing research suggests additional clinical applications for MT2, including the management of erectile dysfunction in men [7].

MT2 is not currently approved for human use and remains the subject of active research for its various potential uses.


Melanotan 1 vs. Melanotan 2 | Benefits and Research Applications

MT1 and MT2 have shown various potential benefits thanks to their action on the melanocortin receptors.

Below, we’ll outline some of the most notable benefits observed with both compounds.

Melanotan 1 vs. Melanotan 2 for Skin Health and Tanning

Both MT1 and MT2 have been reported to stimulate MC1R for increased skin pigmentation:

  • MT1 has been reported to cause tanning without exposure to sunlight. Further, the running effect helps reduce sunburn in subsequent sunlight/UV exposure by 47% [5].
  • MT2 significantly upregulates melanin production and results in skin tanning. Researchers have observed an effect that is similar to that observed in previous MT1 studies [8].

While both peptides have been shown to cause sunless tanning, MT1 is considerably more selective towards the MC1R.

Thus, it has been investigated thoroughly as an agent for increasing tolerance to sunlight in several conditions:

  • Polymorphic light eruption (abnormal immune reaction and rash due to sunlight/UV exposure): Phase 3 studies show that MT1 reduces the severity of polymorphic light eruption rashes triggered by sunlight exposure when administered as a 16mg implant for four months [9].
  • EPP: The FDA has approved MT1 as a treatment for EPP based on the results of three phase 3 trials, which included 244 adults with the condition. The peptide effectively increases melanin in the skin, which acts as a natural sunscreen to alleviate pain and scarring in EPP [10].

Melanotan 1 vs. Melanotan 2 for Sexual Function

The benefits of melanocortin agonists for libido and erectile function owe primarily to its activation of MC4R.

Thus, MT2 is considerably more effective for sexual function than MT1 and can boost sex drive in both males and females [11, 12].

Here is some of the most notable research on melanotan 2 for sexual health:

  • In an early study, MT2 improved erectile function in 85% of study volunteers suffering from erectile dysfunction (ED) due to various causes. The average erection duration was 41 minutes in the MT2 group, and 68% of patients reported an increase in sexual desire. Thus, MT2 has been posited as an alternative for commonly used PDE5 inhibitors like sildenafil [13].
  • MT2 has been reported to enhance proactive sexual behavior in rats administered a combination of estradiol benzoate and progesterone, suggesting an increase in sexual desire. Another peptide called PT-141, which is a metabolite of MT2, is already approved for therapy in women with hypoactive sexual desire disorder (HSDD) [14, 15].

Other Benefits of Melanotan 1 vs. Melanotan 2

MT1 and MT2 may also provide additional benefits related to their structure and melanocortin receptor affinity, including:

  • MT1 may provide anti-inflammatory benefits. According to a small clinical study, MT1 helped to reduce inflammation in acne lesions within 56 days of administration via a 16mg implant. More data is needed to confirm this benefit and the potential mechanisms involved [16].
  • MT2 may suppress appetite and induce weight loss. MT2 interacts with MC3R and MC4R, potentially reducing appetite and leading to weight loss. The available research is only preclinical and suggests that the peptide’s appetite-suppressing effect is dose-dependent, leading to reduced energy intake and weight loss [17, 18].

Melanotan 1 vs. Melanotan 2 | Side Effects and Complications

Overall, MT1 appears to be more thoroughly studied regarding potential side effects after short-term and long-term application.

Moreover, the peptide is already approved for human use by the FDA in the form of subcutaneous implants. Nevertheless, MT1 is not free of adverse reactions and risks.

Here are more details on the potential side effects of MT1 [19]:

  • Long-term phase 3 studies of up to 8 months in duration highlight a favorable safety profile for MT1 without noting any significant adverse effects, even after 180-270 days of administration.
  • MT1 is generally safe with minimal side effects. The most frequent issues reported from the phase 3 studies are nausea (19%), fatigue (6%), skin darkening (4%), dizziness (4%), and the development of moles (4%).

Conversely, findings on the safety profile of MT2 are primarily based on short-term studies. Notable findings include:

  • A substantial review involving 80 male participants identified nausea (41%) and stretching/yawning (56%) as the most common side effects. Other effects include flushing, changes in appetite, and sleepiness [13, 20].
  • Although increased erections are often a sought-after effect of MT2, there have been instances of prolonged and painful erections (priapism) reported in case studies [21].
  • Evidence suggests a link between prolonged MT2 use (over one month) combined with other tanning methods, such as sunbeds, and the development of rapidly changing moles or skin cancer [22, 23].

Both MT1 and MT2 are contraindicated in subjects who are pregnant, breastfeeding, under 18 years of age, or who have a prior history of skin-related malignancies.


What is the Biggest Difference Between Melanotan 1 vs. Melanotan 2?

MT1 and MT2 exhibit numerous differences in terms of molecular structure, receptor binding affinity, potential side effects, dosage, and regulatory status.

Therefore, there are multiple factors to consider when outlining the biggest differences between the two melanocortin agonists:

  • Molecular Structure: While both MT1 and MT2 are synthetic analogs of alpha-MSH, they have only four amino acids in common: the sequence His-D-Phe-Arg-Trp (positions three to six in MT2).

    Moreover, MT1 is a linear tetradecapeptide, while MT2 is characterized by a cyclic heptapeptide arrangement [3].

    This structural variance significantly affects their interaction with melanocortin receptors in the body, thereby influencing their potential therapeutic impact and side effects [5].

  • Receptor Binding: MT1 predominantly targets MC1R, which plays a role in melanin production. The peptide is recognized for its use in skin tanning and treating UV/sunlight sensitivity disorders [24].

    Conversely, MT2 interacts with several receptors (MC1R, MC3R, and MC4R), with further impact on metabolic and sexual functions. Its research applications extend to sexual dysfunction, behavioral issues, and obesity management [13, 18, 25].

  • Side Effects: MT1 is associated with relatively mild side effects, including localized adverse reactions, nausea, facial flushing, and tiredness [10].

    By contrast, MT2 can lead to diverse effects ranging from mild complaints such as nausea and yawning to potentially serious side effects like increased melanoma risk [13, 21, 22].

  • Legal Status and Dosage: MT1 is approved by the FDA for sunless tanning and treating erythropoietic protoporphyria as a subcutaneous implant. It is commonly dosed at 1-2mg/daily over 10 days, followed by a maintenance dose [5].

    MT2 is not FDA-approved and therefore largely restricted to research use. In tanning studies, its dosage is limited to 0.5mg/daily for up to 14 days. For libido enhancement research, dosages of 1-2mg/daily are administered up to four times monthly, with a minimum 48-hour interval between the administrations [8, 13, 26].


Melanotan 1 vs. Melanotan 2 | Which is Better?

Whethr MT1 or MT2 is the better option for a scientific experiment will depend on the specific research objective and desired outcomes.

MT1 appears to be the top option for researchers looking to investigate the potential of melanocortin agonists for [5, 9, 10, 16]:

  • Sunless tanning
  • Reducing the risk of sunburn
  • Increasing tolerance to UV/sunlight
  • Reducing inflammation

That is because MT1 has considerably higher selectivity towards MC1R, whose activation is the primary factor that mediates the aforementioned effects.

At the same time, selectivity also reduces the risk of certain undesired effects.

While MT2 also has the potential to activate MC1R and stimulate melanogenesis, the peptide has a broader affinity towards other melanocortin receptors.

Thus, it appears to be the better option for researchers looking to investigate the potential of melanocortin agonists for [13, 14, 17, 18]:

  • Increasing libido
  • Improving erections
  • Regulating metabolic rate
  • Suppressing appetite

Melanotan 1 vs Melanotan 2


Where to Order Melanotan 1 and Melanotan 2 Online?

When selecting melanotan for research purposes, it's imperative to prioritize product quality and reliable shipping.

The online market for peptides has unfortunately been flooded with dubious vendors and subpar products. This makes the choice of a reliable supplier a crucial one.

Our expertise at Peptides.org is invaluable in guiding researchers toward trustworthy sources.

Based on its proven reliability and exceptional product standards, we highly recommend the following vendor of research peptides including MT1 and MT2.

Xcel Peptides

Xcel Peptides is a US-based peptide vendor that stands out for numerous reasons, earning its reputation as a preferred supplier within the scientific community:

  • Exceptional Peptide Quality: Every Xcel Peptides product adheres to the highest quality benchmarks, as evidenced by rigorous third-party testing. Their website proudly displays lab test results for both MT1 and MT2, confirming a minimum purity of 99%.
  • Competitive Pricing: Xcel Peptides offers premium-grade peptides at unbeatable prices. 10mg vials of MT1 are currently priced at only $45 each, while MT2 retails for $39 per 10mg vial.
  • Hassle-Free Checkout: The SSL-encrypted website facilitates a secure and quick checkout process, accepting various payment methods including credit cards and Zelle.
  • Free Shipping & Outstanding Customer Service: Xcel Peptides boasts a responsive support team that addresses inquiries within one business day. Orders over $200 even qualify for free shipping.

Xcel Peptides exemplifies the standards of reliability and quality that researchers should seek when procuring peptides for their work.

Be sure to also sign up to the vendor’s informative email newsletter for a special 10% off!

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Melanotan 1 vs. Melanotan 2 | Overall

Melanotan 1 and melanotan 2 are two alpha-MSH analogs with significant research potential in the fields of sunless tanning, skin health, appetite suppression, and erectile dysfunction.

MT1 is particularly suited for investigations into its protective effect against sunlight and UV light, while MT2 shows promise in areas like appetite suppression and enhancement of sexual function in both men and women.

Researchers looking to include MT1 and/or MT2 in their studies are encouraged to visit our top recommended peptide vendor for quality peptides at unbeatable prices.


References

  1. Mahiques-Santos L. (2012). Melanotan [Melanotan]. Actas dermo-sifiliograficas, 103(4), 257–259. https://doi.org/10.1016/j.ad.2011.08.002
  2. Moscowitz, A. E., Asif, H., Lindenmaier, L. B., Calzadilla, A., Zhang, C., & Mirsaeidi, M. (2019). The Importance of Melanocortin Receptors and Their Agonists in Pulmonary Disease. Frontiers in medicine, 6, 145. https://doi.org/10.3389/fmed.2019.00145
  3. Minder, E. I., & Schneider-Yin, X. (2015). Afamelanotide (CUV1647) in dermal phototoxicity of erythropoietic protoporphyria. Expert review of clinical pharmacology, 8(1), 43–53. https://doi.org/10.1586/17512433.2014.956089
  4. Al Shaer, D., Al Musaimi, O., Albericio, F., & de la Torre, B. G. (2020). 2019 FDA TIDES (Peptides and Oligonucleotides) Harvest. Pharmaceuticals (Basel, Switzerland), 13(3), 40. https://doi.org/10.3390/ph13030040
  5. Dorr, R. T., Ertl, G., Levine, N., Brooks, C., Bangert, J. L., Powell, M. B., Humphrey, S., & 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. https://doi.org/10.1001/archderm.140.7.827
  6. Modi, M. E., Inoue, K., Barrett, C. E., Kittelberger, K. A., Smith, D. G., Landgraf, R., & Young, L. J. (2015). Melanocortin Receptor Agonists Facilitate Oxytocin-Dependent Partner Preference Formation in the Prairie Vole. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 40(8), 1856–1865. https://doi.org/10.1038/npp.2015.35
  7. 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), 1098–1106.
  8. 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. https://doi.org/10.1016/0024-3205(96)00160-9
  9. A Phase III, randomised, double blind, placebo controlled study to evaluate the safety and efficacy of subcutaneous implants of afamelanotide (16 mg) in patients suffering from polymorphic light eruption (PLE). (2009) EUCTR2009‐010843‐15‐NL. Retrieved from https://trialsearch.who.int/Trial2.aspx?TrialID=EUCTR2009-010843-15-NL. Added to CENTRAL: 31 March 2019 | 2019 Issue 3.
  10. US Food and Drug Administration. (n. d.). Drug Trials Snapshots: SCENESSE. Retrieved [November 10, 2023], from https://www.fda.gov/drugs/drug-approvals-and-databases/drug-trials-snapshots-scenesse
  11. Hadley M. E. (2005). Discovery that a melanocortin regulates sexual functions in male and female humans. Peptides, 26(10), 1687–1689. https://doi.org/10.1016/j.peptides.2005.01.023
  12. Ückert, S., Bannowsky, A., Albrecht, K., & Kuczyk, M. A. (2014). Melanocortin receptor agonists in the treatment of male and female sexual dysfunctions: results from basic research and clinical studies. Expert opinion on investigational drugs, 23(11), 1477–1483. https://doi.org/10.1517/13543784.2014.934805
  13. 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 Suppl 4, S74–S79. https://doi.org/10.1038/sj.ijir.3900582
  14. Rössler, A. S., Pfaus, J. G., Kia, H. K., Bernabé, J., Alexandre, L., & Giuliano, F. (2006). The melanocortin agonist, melanotan II, enhances proceptive sexual behaviors in the female rat. Pharmacology, biochemistry, and behavior, 85(3), 514–521. https://doi.org/10.1016/j.pbb.2006.09.023
  15. Edinoff, A. N., Sanders, N. M., Lewis, K. B., Apgar, T. L., Cornett, E. M., Kaye, A. M., & Kaye, A. D. (2022). Bremelanotide for Treatment of Female Hypoactive Sexual Desire. Neurology international, 14(1), 75–88. https://doi.org/10.3390/neurolint14010006
  16. Böhm, M., Ehrchen, J., & Luger, T. A. (2014). Beneficial effects of the melanocortin analogue Nle4-D-Phe7-alpha-MSH in acne vulgaris. Journal of the European Academy of Dermatology and Venereology : JEADV, 28(1), 108–111. https://doi.org/10.1111/j.1468-3083.2012.04658.x
  17. Baldini, G., & Phelan, K. D. (2019). The melanocortin pathway and control of appetite-progress and therapeutic implications. The Journal of endocrinology, 241(1), R1–R33. https://doi.org/10.1530/JOE-18-0596
  18. Côté, I., Sakarya, Y., Kirichenko, N., Morgan, D., Carter, C. S., Tümer, N., & Scarpace, P. J. (2017). Activation of the central melanocortin system chronically reduces body mass without the necessity of long-term caloric restriction. Canadian journal of physiology and pharmacology, 95(2), 206–214. https://doi.org/10.1139/cjpp-2016-0290
  19. Highlights of prescribing information … SCENESSE. (n.d.). Retrieved October 10, 2023, from https://scenesse.com/wp-content/uploads/2022/11/us-prescribing-information-clean-202210.pdf
  20. Wessells, H., Gralnek, D., Dorr, R., Hruby, V. J., Hadley, M. E., & Levine, N. (2000). Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. Urology, 56(4), 641–646. https://doi.org/10.1016/s0090-4295(00)00680-4
  21. Dreyer, B. A., Amer, T., & Fraser, M. (2019). Melanotan-induced priapism: a hard-earned tan. BMJ case reports, 12(2), e227644. https://doi.org/10.1136/bcr-2018-227644
  22. Cousen, P., Colver, G., & Helbling, I. (2009). Eruptive melanocytic naevi following melanotan injection. The British journal of dermatology, 161(3), 707–708. https://doi.org/10.1111/j.1365-2133.2009.09362.x
  23. Hjuler, K. F., & Lorentzen, H. F. (2014). Melanoma associated with the use of melanotan-II. Dermatology (Basel, Switzerland), 228(1), 34–36. https://doi.org/10.1159/000356389
  24. Mun, Y., Kim, W., & Shin, D. (2023). Melanocortin 1 Receptor (MC1R): Pharmacological and Therapeutic Aspects. International journal of molecular sciences, 24(15), 12152. https://doi.org/10.3390/ijms241512152
  25. Minakova, E., Lang, J., Medel-Matus, J. S., Gould, G. G., Reynolds, A., Shin, D., Mazarati, A., & Sankar, R. (2019). Melanotan-II reverses autistic features in a maternal immune activation mouse model of autism. PloS one, 14(1), e0210389. https://doi.org/10.1371/journal.pone.0210389
  26. 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.

Scientifically Fact Checked by:

David Warmflash, M.D.

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