A man who's spent nearly two decades using a synthetic peptide to chase an extreme tan has shared before-and-after photos on Reddit, sparking fresh debate about a drug health authorities have been warning against for over a decade.
What the "Barbie drug" actually is
Melanotan II, nicknamed the "Barbie drug" and sometimes the "vacation peptide," is a synthetic hormone-like substance that's either injected or taken as a nasal spray. According to Cancer Research UK, it works by stimulating pigment cells in the skin to produce more melanin, giving users a darker tan without needing sun exposure to trigger it directly. It's illegal to sell or supply in the UK, and has never been approved by the FDA in the US either.
Nearly two decades of use
Posting under the username n3glv, the man behind the viral before-and-after images has said he's been injecting Melanotan II for roughly 17 years, using a loading phase to let his body adjust before spending time in the sun. He's described the process as slow, saying it can take close to two weeks before sun exposure produces visible results, and has been clear that the drug itself offers no protection from sunburn during that window.
He's also warned other users to keep a close eye on their moles while taking it, since changes in size or shape can become harder to spot once a deeper tan sets in.
A drug regulators have been flagging for over a decade
The UK's medicines regulator, the MHRA, first issued a public warning about Melanotan products back in 2009, and has continued raising concerns since. In one earlier crackdown, the agency worked with internet providers to shut down more than 70 websites illegally selling the drug to UK customers within a single three-month period, after receiving multiple reports of adverse reactions including stomach, heart, blood, and eye problems.
Government records show the regulator has continued logging adverse reaction reports linked to Melanotan II in the years since, covering a range of side effects reported through its official reporting scheme. A 2013 case report published in a US medical journal also linked the drug to a rare but serious neurological condition affecting the brain's blood vessels, broadening concerns beyond skin and cardiovascular effects.
What doctors say about the risks
Dr Donald Grant, a GP and senior clinical advisor at The Independent Pharmacy, has warned that because Melanotan II isn't a regulated medicine, users often have no way of knowing exactly what they're injecting into their bodies. He's flagged an increased skin cancer risk, since the drug can darken existing moles or trigger new ones, along with side effects ranging from nausea to kidney or muscle damage.
A study of 28 users published in the British Journal of Dermatology recorded common side effects including nausea and increased libido, alongside rarer but more serious outcomes, including abnormal mole growth and renal infarction, a medical emergency involving disrupted blood flow to the kidneys.
Despite the risks, some long-term users, including the man behind the viral photos, say they've stuck with it because of the results. Whether that's a trade-off worth making is something health experts are united in advising against.
