Online 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 to enter within 24 hours.
Health experts warn these promotions create serious risks.
They misuse marketing tactics designed to reduce caution.
One group offered retatrutide, Glow pens, and melanotan II as prizes.
None of these injectable products have UK approval.
UK law allows weight-loss injections only with a prescription.
Unapproved drugs cannot be legally sold or advertised.
Another seller disguises drug sales as fitness coaching programmes.
Platform owners say they ban illegal drug sales.
