# Melanotan II's tested cousin raised melanin 41% in fair skin

URL: https://sciencebased.news/melanotan-ii/
Published: 2026-10-23  Updated: 2026-10-30
Claim: Melanotan II injections give you a tan without the sun. Grade: Weak

What to do:
- Not proven: that melanotan II tans you safely. It was tested for tanning in 3 men, and its safety record is case reports, including melanoma in moles.
- For color without the sun, use a self-tanner with DHA. It dyes only the top layer of skin and needs no injection. It does not block UV, so keep your sunscreen on.
- If sunlight makes your skin burn with pain within minutes, ask a doctor about EPP. The approved melanotan drug, afamelanotide, gave people with it more pain-free hours in the sun.
- Safety: if you have used melanotan II, tell your doctor and show a skin doctor any new mole or one that changed. An erection that will not go down is an emergency.


# Melanotan II's tested cousin raised melanin 41% in fair skin

*Evidence check, October 23, 2026. Updated October 30, 2026.*

> **The claim:** "Melanotan II injections give you a tan without the sun."
>
> **Our grade: Weak.** A close cousin of the drug, tested properly in 79 people, did build a real tan in fair skin and is approved for a rare light disease. Melanotan II itself was tried for tanning in 3 men, and what is known about its safety comes from case reports.

![A small glass vial labeled MELANOTAN II and a capped syringe lie on a striped beach towel in bright sun, beside sunglasses and a bottle of sunscreen](https://sciencebased.news/images/melanotan-ii-hero.jpg)

Your summer tan is fading, you burn in 15 minutes, and your feed keeps showing the "vacation peptide": a few shots and you turn brown without the sunburn.

Does a shot really tan you?

One melanotan drug does. In a 2006 trial in Sydney and Adelaide, 79 fair-skinned adults got daily injections of a melanotan drug or a dummy for 3 months, in autumn and winter, with the sun mostly avoided [3]. The skin of those who burn easily made 41% more melanin, the brown pigment that soaks up UV light. The catch is which melanotan it was, because there are two, and they are not the same drug.


## Where the claim came from

Melanotan II was made in the 1990s as a stronger, ring-shaped copy of α-MSH, the hormone that tells skin cells to make melanin. It never got past early trials, but it is sold online as a powder, as a "research peptide" or nasal spray. It has been nicknamed the "Barbie drug", and on social media the "vacation peptide".

On April 1, 2024, Andrew Huberman covered it in his episode "Benefits & Risks of Peptide Therapeutics for Physical & Mental Health" [1]. He said melanotan peptides "lead to darkening of the skin by way of activating melanocytes", and because they reach the brain, "the pattern is to increase mood and libido and to decrease appetite." He also warned that "folks with melanoma should be very cautious about using any of the peptides that stimulate melanocytes."

On April 13, 2026, Peter Attia gave it a segment of "Peptides—evaluating the science, safety, and hype in a rapidly growing field" [2]. He put it in his group of peptides with a real mechanism that were never fully tested: it was dropped after phase 2 trials, and its maker moved on to a narrower cousin. His summary: "Melanotan-II's lack of regulation, the lack of long-term data, the lack of receptor specificity means that the risks are going to be higher than anything out of the selective ones."

So there are two drugs here. One was tested in hundreds of people. The other is the one in the vials. Which one did the tanning trial use?

## The cousin that was tested

The drug in the 2006 trial was melanotan I, now called afamelanotide [3]. It is a straight-chain copy of α-MSH, made to last longer in the body. Fifty-nine people got it and 20 got a dummy shot, with no one knowing which. Sixty-five finished. A light meter measured melanin at eight places on the body, from the forehead to the calf, before and after.

The palest skin gained the most. In the 30 treated people who burn easily, melanin rose 41% over 3 months. In 17 treated people who rarely burn, it rose 12%. In the dummy groups it fell 12% and 6%, as winter tans faded. Each gap with the dummy groups was far too big to be chance (P<0.0001). Skin samples told the same story: pigment cells in the easy-burners went from 901 to 1,453 per square millimetre, up 61%.

![Bar chart of the change in skin melanin after 3 months in a randomized trial of 65 adults. People who burn easily: afamelanotide plus 41% (30 people), dummy shot minus 12% (14 people). People who rarely burn: afamelanotide plus 12% (17 people), dummy shot minus 6% (4 people).](https://sciencebased.news/images/melanotan-ii-chart.png)
*Redrawn from Figure 2 and the text of Barnetson et al. [3]. Melanin measured by light at 8 skin sites.*

The tan also blocked some damage. After a dose of UV light three times what reddens their skin, the treated easy-burners had over 50% fewer sunburn cells, skin cells that die from UV harm [3]. In 8 treated people, UV damage to DNA in the deepest layer of the skin, where skin cancers start, was 59% lower than before treatment.

That cousin went on to an approval. In two randomized trials of 168 people with erythropoietic protoporphyria (EPP), a rare disease in which sunlight causes burning pain within minutes, an implant of afamelanotide under the skin every 2 months gave more time in the sun without pain [4]. In the US trial, people spent a median 69.4 hours in direct sun without pain over 6 months, against 40.8 hours on the dummy implant. In the European trial, painful light reactions fell from 146 to 77. It is approved in Europe and, since 2019, in the US as Scenesse [6]. In 115 patients followed for up to 8 years, side effects were minor, mostly nausea [5].

## What melanotan II itself has shown

So what about melanotan II itself? Its tanning evidence is one small test in 3 men. Its other trials were about erections, which it causes because it also works on brain receptors. That is where the libido talk comes from, and the nausea.

The tanning test, in 1996, gave melanotan II to 3 men on alternating days for 2 weeks, with a salt-water shot on the other days [7]. Two of the 3 had darker skin on the face, upper body and buttocks a week after the last dose. They also had nausea at most doses, sleepiness, yawning and stretching, and erections that came on their own and lasted 1 to 5 hours.

The first melanotan I trial, in 1991, is the fairer comparison: 28 healthy white men, randomized, with a dummy group and 7 weeks of follow-up [21]. Skin darkened in both pale and darker skin types, peaking 1 to 3 weeks after the last shot, and not at all with the dummy.

Two crossover trials, in which each man got the drug and a dummy on different days, tested melanotan II for erection problems. In 10 men whose cause was psychological, most got erections they did not get on the dummy [8]. In 10 men with a physical cause, it worked too, but severe nausea followed 4 of the 19 injections [9].

The erection work became bremelanotide, a close relative given as a shot before sex. It is approved in the US as Vyleesi for low sexual desire in women before menopause, with nausea in 40% of users and dark patches on the face or gums in 1% [10]. It gets its own check.

So the shot in the 2006 trial was not the shot in the vials. The tested cousin built a tan that blocked some UV damage. Melanotan II has never had that test.

## What is not known, and what has gone wrong

The limit is that melanotan II has no tanning trial and no long-term safety data, so what is known comes from people who used it and ended up in a clinic. Case reports cannot say how often a harm happens. They can show what is possible.

Moles are the main worry. A 2017 review counted four melanomas, the deadliest skin cancer, that grew from existing moles during or soon after melanotan use, plus moles that darkened or appeared in a rush [11]. In one report, a 20-year-old woman who burns easily used tanning beds and 3 to 4 weeks of melanotan II shots; three months later a black mole on her buttock was a melanoma [12]. Nobody can say whether the drug caused it. In June 2026, Australian skin specialists said they were seeing abnormal moles in users, most often teenagers and people in their early 20s [17].

Other harms have been reported. A man had an erection that lasted for hours and needed surgery, the third such case in print [13]. A 39-year-old man who injected six times his first dose got muscle breakdown and kidney damage [14]. A Swedish report linked it to a blocked artery in the kidney, and Sweden's poison centre had 215 calls about melanotan II from 2008 to 2019 [15]. The FDA lists it among compounding substances that may be risky, citing melanoma, a brain swelling syndrome, an overdose-like reaction and priapism [16].

The product is a second unknown. What is sold is not checked for purity or strength. Selling it as a medicine is illegal in the UK [18], and the FDA sent warning letters to five online peptide sellers in August 2026 [20].

Even the tested cousin carries a warning on its label: it can darken moles and freckles, and users are told to have a full skin check twice a year [6].

## Our grade

The grade splits in two: the idea of a drug-made tan has a real trial behind it, and the product people inject does not.

| Claim | Evidence | Grade |
|---|---|---|
| Melanotan II darkens skin | 1 small test, 3 men, 2 weeks, salt-water shots on alternate days [7] | Weak |
| Melanotan II causes erections | 2 crossover trials, 10 men each [8, 9] | Promising |
| A melanotan drug (afamelanotide) tans fair skin and cuts UV damage | 1 randomized trial, 79 adults, 3 months [3] | Promising |
| Afamelanotide gives people with EPP more pain-free sun | 2 randomized trials, 168 people, plus 8 years of follow-up [4, 5] | Solid |
| Melanotan II is safe to use for tanning | No trials; case reports of melanoma, new moles, priapism, kidney and muscle damage [11-16] | Unproven |
| Overall: melanotan II gives you a tan without the sun | It probably darkens skin, but that rests on 3 men and an approved cousin; its safety is unknown | Weak |

The case for the other side: melanotan II and afamelanotide work on the same receptor in pigment cells, so it would be odd if melanotan II did not tan. In a study of 205 people posting on UK and Irish forums, users described it as working [22].

A tan can also protect. The 2006 trial showed a drug-made tan blocking some UV damage to DNA, and fair skin burns because it has too little melanin.

Against that, the 2006 trial was paid for by afamelanotide's maker, Clinuvel, and some authors worked for it. The sunburn-cell drop was not clearly bigger than in the dummy group, where it fell 26% (P=0.28), and the DNA result had no dummy group.

What would change the grade: a randomized trial of melanotan II for tanning, with skin checks for moles over years, or a clean product with a label. Neither exists.

## What this means for you

If you want a tan without the burn, the sure way is a self-tanner with DHA, a sugar that browns the top layer of dead skin cells. The FDA allows it on the skin, and it needs no injection [19]. It washes off in days and does not block UV, so sunscreen and shade still do the protecting.

If sun gives you burning pain within minutes, ask a doctor about EPP. That is the one group with a proven melanotan drug, and it bought patients a median of about 29 more pain-free hours in the sun over 6 months [4].

If you have used melanotan II, tell your doctor and show a dermatologist your moles, especially any that are new, darker or changing. Melanoma found early is far easier to treat.

The hopeful part is real: a drug can teach pale skin to make its own melanin, and a tan made that way blocked some of the damage the sun does. That idea was tested and approved. The safe way to borrow it today is a bottle of self-tanner and a good sunscreen.



## What's next

The FDA's advisers are due to discuss melanotan II, with GHK-Cu and other peptides, by the end of February 2027 [20]. That review is the first official look at what the vials hold and whether pharmacies may make it. We will update this article when it reports.

This is the ninth of our one-by-one checks on the peptides in [our guide to the best peptides](/peptide-guide/), after [GHK-Cu](/ghk-cu/), [TB-500](/tb-500/) and [AOD-9604](/aod-9604/). Our [peptides article](/peptides/) covers BPC-157. Bremelanotide, melanotan II's cousin for desire, has [its own check](/pt-141/).

## Sources

1. Huberman Lab. Benefits & Risks of Peptide Therapeutics for Physical & Mental Health. Podcast episode, April 1, 2024. https://www.hubermanlab.com/episode/benefits-risks-of-peptide-therapeutics-for-physical-mental-health
2. Attia P. #387 AMA #83: Peptides—evaluating the science, safety, and hype in a rapidly growing field. *The Peter Attia Drive*, April 13, 2026. https://peterattiamd.com/ama83/
3. Barnetson RS, Ooi TK, Zhuang L, et al. [Nle4-D-Phe7]-α-melanocyte-stimulating hormone significantly increased pigmentation and decreased UV damage in fair-skinned Caucasian volunteers. *Journal of Investigative Dermatology*, 2006. 79 adults, randomized, placebo-controlled, 3 months; some authors worked for or advised Clinuvel, the drug's maker. https://doi.org/10.1038/sj.jid.5700317
4. Langendonk JG, Balwani M, Anderson KE, et al. Afamelanotide for erythropoietic protoporphyria. *New England Journal of Medicine*, 2015. Two randomized, placebo-controlled trials, 74 and 94 patients, 6 to 9 months; funded by Clinuvel. https://doi.org/10.1056/NEJMoa1411481
5. Biolcati G, Marchesini E, Sorge F, et al. Long-term observational study of afamelanotide in 115 patients with erythropoietic protoporphyria. *British Journal of Dermatology*, 2015. 115 patients, observational, up to 8 years. https://doi.org/10.1111/bjd.13598
6. US Food and Drug Administration. Scenesse (afamelanotide) implant, prescribing information. 2019. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210797s000lbl.pdf
7. Dorr RT, Lines R, Levine N, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. *Life Sciences*, 1996. 3 men, single-blind, 2 weeks. https://doi.org/10.1016/0024-3205(96)00160-9
8. Wessells H, Fuciarelli K, Hansen J, et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. *Journal of Urology*, 1998. 10 men, randomized crossover. https://pubmed.ncbi.nlm.nih.gov/9679884/
9. Wessells H, Gralnek D, Dorr R, et al. Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. *Urology*, 2000. 10 men, randomized crossover. https://doi.org/10.1016/s0090-4295(00)00680-4
10. US Food and Drug Administration. Vyleesi (bremelanotide) injection, prescribing information. 2019. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
11. Habbema L, Halk AB, Neumann M, et al. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. *International Journal of Dermatology*, 2017. Review of case reports. https://doi.org/10.1111/ijd.13585
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13. Mallory CW, Lopategui DM, Cordon BH. Melanotan tanning injection: a rare cause of priapism. *Sexual Medicine*, 2021. Case report, 1 man. https://doi.org/10.1016/j.esxm.2020.100298
14. Nelson ME, Bryant SM, Aks SE. Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. *Clinical Toxicology*, 2012. Case report, 1 man. https://doi.org/10.3109/15563650.2012.740637
15. Peters B, Hadimeri H, Wahlberg R, Afghahi H. Melanotan II: a possible cause of renal infarction: review of the literature and case report. *CEN Case Reports*, 2020. Case report and Swedish poison centre data. https://doi.org/10.1007/s13730-020-00447-z
16. US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
17. ABC News (Australia). Abnormal moles seen developing in patients chasing perfect suntan by using peptide melanotan-II. June 5, 2026. https://www.abc.net.au/news/2026-06-05/melanotan-ii-peptides-warning-by-specialists-abormal-moles/106749628
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