A Reddit user has caught widespread attention after sharing before-and-after photos that appear to show a dramatic change in his skin tone over nearly 17 years of using Melanotan II, an unapproved tanning peptide. While the images started discussion online, medical experts continue to warn that Melanotan II is an unregulated product that has not been approved for cosmetic use and may pose serious health risks.

Melanotan II is an unapproved peptide that is sold through unregulated sources.

The Reddit user, who posts under the name “n3glv,” said he has been using Melanotan II for approximately 17 years. He shared before-and-after photos showing a much darker complexion than in earlier images, with the transformation quickly gaining attention on social media.

According to his Reddit posts, he has spent years discussing his experience with the peptide and answering questions from other users interested in achieving a similar tan. However, these claims are based on his own account and have not been independently verified.

The images have renewed interest in Melanotan II, a synthetic peptide that is often promoted online as a way to achieve a darker skin tone without relying entirely on sun exposure.

Melanotan II is a laboratory-made peptide designed to mimic alpha-melanocyte-stimulating hormone (α-MSH), a natural hormone involved in stimulating melanin production. Melanin is the pigment that gives skin, hair, and eyes their color.

Although Melanotan II is widely sold through online marketplaces, it has not been approved by the U.S. Food and Drug Administration (FDA) for any use. Health organizations also warn that products sold online are largely unregulated, meaning buyers cannot be certain of their ingredients, purity, or dosage.

Medical experts say a darker tan should not be viewed as protection against the harmful effects of UV radiation.

In one Reddit discussion, the user said one of the biggest mistakes people make is assuming Melanotan II immediately protects them from ultraviolet (UV) radiation.

He wrote that users should not believe the peptide provides instant UV protection and claimed it took about two weeks before he noticed results after beginning treatment. He also said that Melanotan II does not replace sun protection and advised people not to expose themselves to significant sunlight immediately after starting the product.

These statements reflect the user’s personal experience and should not be considered medical advice.

The Skin Cancer Foundation states that Melanotan II has not been proven to be safe or effective and should not be used as an alternative to established sun-protection measures. Dermatologists continue to recommend sunscreen, protective clothing, and limiting excessive UV exposure to reduce the risk of skin damage.

One of the biggest concerns surrounding Melanotan II is the lack of long-term safety data.

Published medical literature has reported cases of melanoma developing after Melanotan II use, as well as rapid changes in moles and pigmented skin lesions. However, these reports do not prove that the peptide directly caused the cancer. Case reports can identify possible safety concerns but cannot establish a cause-and-effect relationship.

Experts are also concerned that darker skin pigmentation or changes in existing moles could make it more difficult to detect early signs of skin cancer.

Another issue is that, unlike properly licensed medicines, products like Melanotan haven’t been tested for safety, quality, or effectiveness, meaning people who use them take on unknown risks.