Dozens of social-media influencers are promoting banned tanning products to millions of followers, a BBC News investigation has found.
It is illegal in the UK to sell nasal sprays or injectables made with “melanotan-2”, an artificial hormone that can accelerate tanning.
The unlicensed drug is dangerous, dermatologists say, and users should stop immediately.
And there is evidence the untested products may be linked to skin cancer.
The Advertising Standards Agency says all influencers must act responsibly, including ensuring products and the companies they link to are not acting illegally.
When influencers and friends started sporting golden-brown skin, they wanted to know their secret.
Soon, Liv was ordering tanning injections from a UK-based website.
Elaina opted for a nasal spray, which she bought on social media.
For two months, Liv, from Leeds, jabbed her stomach and then went on a sunbed, which she had been told would “activate” the drug.
It gave her headaches but she felt it was worth it – until, eight months later, she found a strangely shaped mole on her thigh.
“It was dark and raised, about the size of a pea,” she says.
“I’m not a ‘moley’ person, so I knew something wasn’t right.”
Doctors agreed with Liv.
But shortly after the mole was removed, she was diagnosed with stage-one melanoma, a skin cancer that can be life-threatening.
Liv needed surgery to remove the cancerous tissue around the area where the mole had been and her dermatologist told her the injections were the likely cause.
“A cancer diagnosis is terrifying, never mind when you’re 27 years old,” she says.