Shocking Truth: Long-Term Melanotan II User Reveals the Hidden Dangers You Need to Know

A man who says he has used the tanning peptide Melanotan II for almost two decades has issued a warning to people thinking about trying the controversial product, claiming one common mistake could put users at greater risk. One of the many advantages of holidaying in the sun is returning with a deep, golden tan — a look synonymous with both health and superficial desirability. Online popularity around tanning products As awareness grows around the dangers of excessive sun exposure, many people are turning to alternatives in order to attain a bronzed complexion. While most opt for traditional fake tan products, some are using Melanotan II, an unregulated synthetic peptide designed to stimulate the body's production of melanin. Often referred to online as the "Barbie drug" or "Vacation peptide," Melanotan II can be injected or administered as a nasal spray. However, as of 2026, it remains untested, unregulated and illegal to sell in many countries, including the UK. User issues warning Despite this, online communities dedicated to the drug continue to grow, with one Reddit user claiming to have relied on Melanotan II for approximately 17 years. Posting under the username n3glv, the long-term user has regularly shared photos documenting his dramatic change in skin tone, while also offering advice to newcomers considering the peptide. After nearly two decades of use, he said the biggest error he sees is people assuming the drug immediately protects them from the effects of the sun. "Biggest issue I have seen is people thinking [Melanotan] is instant UV protection and jumping into UV already," he wrote. "Don't make that mistake." Although Melanotan II can darken the skin on its own, exposure to ultraviolet (UV) light is generally what deepens a person's tan. According to n3glv, the peptide takes time to build up in the body, explaining that it took around two weeks of "loading" before he noticed significant results. He also stressed that the drug should never be viewed as a substitute for sun protection. "It doesn't do anything to protect you [from the sun], what it does is trigger your body to make more melanin," he explained. "So be careful with sun exposure in the beginning. It will take around two weeks before you can take ANY sun." Melanotan II has not been approved for cosmetic tanning and has not undergone the level of safety testing required for licensed medicines. The NHS warns that commonly reported side effects include: Nausea Drowsiness Vomiting Loss of appetite More serious complications have also been linked to its use, including an increased risk of skin cancer, kidney infections and renal failure. One published case report described a 55-year-old man who experienced a prolonged erection lasting 30 hours after using Melanotan, as certain versions of the peptide have also been investigated as potential treatments for erectile dysfunction. Because the drug is sold through unregulated sources, experts also warn that users cannot be certain what ingredients are actually contained in the products they purchase. Dr Donald Grant, a GP and Senior Clinical Advisor at The Independent Pharmacy, advised : "Unlike regulated medicines, these products have not been properly tested for safety, quality or effectiveness, and people often don't know exactly what they are putting into their bodies." Featured Image. Credit: mrs / Getty