A video of Robert F Kennedy Jr squirting inky blue liquid into a glass went viral before his swearing-in as US health secretary. The substance was widely believed to be methylene blue, a synthetic fabric dye now popular in wellness circles.
Influencers including Joe Rogan and Bryan Johnson have promoted the dye, claiming it boosts cognition, energy, and has anti-ageing effects. On TikTok, users display blue tongues after taking the substance orally.
Methylene blue was first synthesised in the late 19th century and used as an antimalarial during World War II. Today, it is listed by the World Health Organization as an essential medicine for treating methaemoglobinemia and certain poisonings.
However, experts warn there is no evidence it improves health in healthy individuals. Dr Ian Musgrave of the University of Adelaide says human trials for Alzheimer's have largely failed, and Dr Slade Matthews notes that toxicity has been reported.
Australian poisons centres have seen a rise in calls related to methylene blue ingestion, with some patients developing significant symptoms. The Victorian Poisons Centre states: 'There is no current evidence that methylene blue improves health or brain function in healthy individuals.'
