Hidden sellers promote unlicensed weight-loss drugs through WhatsApp and Telegram giveaways.
They offer injectable medicines as competition prizes.
The Guardian found groups advertising retatrutide, an unapproved experimental drug.
Posts pressure users with 24-hour entry deadlines.
Experts warn these tactics create serious health risks.
They misuse marketing strategies designed to override caution.
One group offered retatrutide, Glow pens, and melanotan II.
None of these injectable products hold UK approval.
UK law allows weight-loss injections only with prescriptions.
Unapproved drugs cannot be legally sold or advertised.
Some sellers disguise drug sales as fitness coaching programmes.
Platform owners say they ban illegal drug sales.
