Hidden-market sellers promote unlicensed weight-loss drugs through WhatsApp and Telegram giveaways.
They offer injectable medicines such as retatrutide as competition prizes.
Experts warn these promotions pose serious health risks.
UK law bans the sale or advertising of unapproved prescription medicines.
Some sellers disguise drug sales as fitness or coaching programmes.
Researchers say these tactics bypass safeguards and endanger the public.
