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.
Liv and Elaina both long for a tan like the models on their social-media feeds.
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.
Within minutes of her first nasal spray, Elaina’s face “burned up” and turned bright red.
“I was told my body just needed to get used to it,” she says.
“A week later, my throat started to close up – I literally couldn’t breathe.”
The 19-year-old, from Stockton-on-Tees, Durham, needed hospital treatment and was diagnosed with a serious throat and sinus infection.
Doctors told her inhaling the tanning product was the cause and they had seen other patients develop similar symptoms after using it.
BBC News has spoken to 20 people who have experienced complications, including lesions, fungal infections and abscesses.
Melanotan-2 can increase the production of melanin, the pigment that darkens skin, but it has never had rigorous safety testing.
Social-media sites have propelled the drug, previously sold in some gyms and salons, into the mainstream, with the trend mainly driven by young, white women.
The recent introduction of a nasal spray can also make it seem more appealing.
The British Association of Dermatologists is now on the alert for patients with warning signs of “unusual orange tans” and “disordered moles”.
Some sellers claim their products are safe – but Dr Catherine Borysiewicz, from the association, says the only safe tan is fake tan.
“We have evidence these products are potentially dangerous and can potentially lead to cancer,” she says.
“We have cases which have shown melanoma developing after trying them.
“I talk about skin risks – but who knows what else it might be doing?”
Dozens of influencers have posted about using melanotan-2.
It is not illegal to use or promote these tanning products, despite the health risks, but it is illegal to sell them.
Geordie Shore star Bethan Kershaw recently told her 700,000 followers she had used nasal sprays from a company called Real Tan.
Both she and the company declined to comment.
Other influencers are more explicit – TikTok star Lauren demonstrated on camera how to inhale the drug.
A company had offered the 26-year-old, from Glasgow, free nasal sprays if she would promote their products.
But after two months, she stopped taking them because they made her feel sick.
“As an influencer, I need to be more careful what I’m promoting,” Lauren says.
“I have got to look out for my followers, a lot of them are young.”
BBC News has also seen many examples of celebrities directing their followers to businesses selling melanotan-2 products.
The most high-profile example is reality-TV star Charlotte Crosby, who on one occasion told her followers to “check out” Real Tan and tagged the company in a separate post talking about her tan.
A representative for Ms Crosby, who has 7.6 million Instagram followers, says she “would never knowingly promote a company illegally selling unlicensed products”.
We are told she has only ever used items from Real Tan which do not contain melanotan-2; these are moisturising creams “gifted to her” and gels she posted about as a favour, to promote their launch.
But these clarifications were not mentioned in her posts.
And there was no mention of creams or gels in Real Tan’s price list after Ms Crosby posted about the seller, only injections and nasal sprays.
A more recent price list says “sun accelerator creams available soon”.
BBC News asked research chemists at Imperial College London to analyse 10 tanning kits.
They would expect to find about 10 ingredients in a licensed medicine but were shocked to discover some of the products contained more than 100 unidentified ingredients.
They also confirmed the presence of melanotan-2.
“If you don’t know what you’re taking, you should probably avoid it,” Prof Tony Cass says.
He likened the risk to Russian roulette but added: “It’s more like using a machine gun than a pistol.”
The Medicines and Healthcare products Regulatory Agency says it has spent 10 years targeting melanotan products.
Instagram and TikTok say selling the drug on their platforms is banned and promotional content will be taken down.
But despite this, the illegal tanning industry is thriving.
Some contributors’ surnames have been withheld
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