Skin

Melanotan II (MT2): the viral tan jab, and what studies really show

Research purposes only Checked against PubMed and official sources Oct 18, 2026

Quick facts

What it is: a lab-made version of α-MSH, the hormone that switches on skin pigment.
Status: research purposes only. Not FDA-approved.
Human evidence: small 1990s trials: darker skin in a 3-man pilot, erections in two 10-man ED studies.
Side effects in studies: nausea, yawning, fatigue, lower appetite, spontaneous erections.
Known risks: mole changes and rare serious events in case reports.

What is Melanotan II?

Melanotan II (MT2, MT-II) is a lab-made, ring-shaped version of alpha-melanocyte-stimulating hormone (α-MSH), the hormone that tells your skin to make pigment. It was first tested in people at the University of Arizona in the 1990s. It's a non-selective melanocortin-receptor agonist (Peters et al., 2020), which is why it touches tanning, libido and appetite all at once.

Is Melanotan II FDA-approved?

Not FDA-approved (Int J Dermatol, 2017). Its cousin afamelanotide (Melanotan I) is: it's Scenesse, an implant for the rare light-sensitivity condition EPP (FDA approval, 2019).

Not FDA-approved; sold for research only. Known risks: new and darkening moles (case report, 2014), melanoma in a 20-year-old who also used sunbeds (single case, 2014; a review says a link isn't proven, 2017), priapism (case, 2021) and kidney infarction (case, 2020). Choose a tested source.

Dosage

The tiny 1990s studies dosed under medical supervision. There's no established human dose, so we don't list one.

What the research shows

The original tanning study (Dorr et al., Life Sci, 1996): a pilot Phase 1 trial in 3 healthy men. After only 5 low-dose injections, 2 of the 3 had measurably darker skin on the face, upper body and buttocks a week later. Side effects: mild nausea, yawning and stretching, fatigue and spontaneous erections.
Erections in men with psychogenic ED (Wessells et al., J Urol, 1998): double-blind, placebo-controlled crossover, 10 men. 8 of 10 had clinically apparent erections. Strong rigidity lasted 38.0 minutes on MT2 vs 3.0 on placebo. Nausea, yawning and decreased appetite were more common on MT2.
Erections and desire with organic ED (Wessells et al., Urology, 2000): 10 men, placebo-controlled. Erections after 12 of 19 MT2 injections vs 1 of 21 placebo, and sexual desire was significantly higher. Severe nausea followed 4 of 19 injections.
Appetite, in animal studies (Neuropeptides, 2022): in one mouse study, MT2 injected directly into a brain reward area cut food intake and the motivation to work for food, without signs of an aversive state.
The buzz is documented: dermatologists have analyzed melanotan content on TikTok (JEADV, 2025) and its "Barbie drug" marketing (JEADV, 2025). A study of 205 forum users found people mainly used it for a tan before sun holidays and fitness competitions (Dermatology, 2021).

New to these terms? See the glossary.

Melanotan II FAQ

Does Melanotan II really tan you?

It darkened skin in a tiny 1996 pilot: 2 of 3 men had measurably darker skin a week after 5 low-dose injections.

Does Melanotan II increase libido?

In two small 1990s trials in men with erectile dysfunction, it triggered erections, and the 2000 study found sexual desire was significantly higher than on placebo.

Does Melanotan II suppress appetite?

Decreased appetite was reported more often on MT2 than placebo in one small 1998 trial (10 men), and it cut food intake in one mouse study (injected directly into the brain).

Is Melanotan II legal?

It's not FDA-approved. Its cousin afamelanotide is approved as Scenesse for the rare condition EPP.

What are the side effects of Melanotan II?

In studies: nausea, yawning and stretching, fatigue, lower appetite and spontaneous erections. Case reports describe new or darkening moles, a few melanoma cases (a causal link isn't proven), priapism and kidney problems.

What's the difference between Melanotan I and II?

Melanotan I is afamelanotide, the FDA-approved drug in Scenesse. Melanotan II is a different, ring-shaped molecule that also acts on the receptors involved in libido and appetite.

Not medical advice. Education only. Talk to a licensed clinician about your health.

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