Small molecule
Methylene Blue
Methylene blue (methylthioninium chloride) is an FDA-approved medication (trade names Provayblue, Proveblue) for the treatment of methemoglobinemia. It is one of the oldest synthetic medicines, first synthesized in 1876. In recent years, it has gained attention in biohacking communities for proposed cognitive enhancement and mitochondrial function benefits at low doses. The FDA-approved formulation is prescription-only; non-pharmaceutical-grade products sold online raise significant quality and purity concerns.
Regulatory watch
Last reviewed 2026-07-01
Next review 2026-07-29