Hidden sellers promote unlicensed weight-loss drugs through WhatsApp and Telegram giveaways.
The Guardian observed groups advertising retatrutide, an experimental drug without approval.
Posts pressure users with 24-hour deadlines and free-entry claims.
Experts warn these tactics create serious health risks.
One group offered retatrutide, Glow pens, and melanotan II as prizes.
None of these injectable products hold UK approval.
UK law allows weight-loss injections only with prescriptions from licensed providers.
Another seller disguises drug sales as fitness coaching.
Telegram and Meta say their rules ban illegal drug sales.
