The Short Version
Methylene blue has not been shown to slow the aging process in humans. Peer-reviewed research describes it as a *potential* anti-aging candidate based on mechanistic studies and limited preliminary findings — mostly in cells, animals, or small cognitive studies. Key human trials are still ongoing, and authoritative sources like MedicalNewsToday and Harvard Health explicitly note that large-scale human evidence is lacking. The claim's phrasing — "has been shown" — significantly overstates the current science.