Collagen supplements – in powders, pills, drinks and gummies – have become one of the most aggressively marketed nutraceuticals of the past decade. Promoted for everything from wrinkle reduction and joint health to gut repair and even brain function, collagen is now firmly embedded in wellness culture. Yet despite its popularity, no authorised health claims currently exist for collagen in the UK or EU. This hasn’t stopped social media platforms such as TikTok and Instagram from being saturated with paid adverts suggesting that collagen supplementation can reverse ageing, strengthen hair and nails, or ‘replace’ lost collagen as we age. For nutrition professionals, this raises important questions: what does the evidence actually support and where does marketing run ahead of science?