Tongue trend: Influencers including Renee Belz (main) and Luba Cohen (inset) have been hawking the benefits of the anti-fungal dye methylene blue. Instagram Doctors are slamming fitness influencers ...

Methylene Blue, chemically known as methylthioninium chloride, is a cationic dye, redox indicator, and photosensitizer. In aquaculture, it acts as an anti-fungal and anti-parasitic drug and is often ...