methylthioninium chloride

Methylthioninium chloride, commonly known as methylene blue, is a small molecule oxidizing-reducing agent developed by Provepharm and marketed under the brand name Proveblue. It is specifically indicated for the treatment of acquired methemoglobinemia in both adult and pediatric patients. Proveblue was the first methylene blue product to receive FDA approval (in 2016) through the modern regulatory pathway, which ensures a high-purity formulation with significantly lower levels of organic impurities and heavy metals (such as mercury, arsenic, and lead) compared to older USP-grade versions. The drug functions by acting as an exogenous electron donor; in the presence of NADPH and the enzyme NADPH-methemoglobin reductase, it is converted to leucomethylene blue, which then reduces the ferric iron (Fe3+) in methemoglobin back to the functional ferrous state (Fe2+) in hemoglobin, thereby restoring the blood's oxygen-carrying capacity.

Brand names

Proveblue

Other names

methylene bluemethylthioninium chloride hydratetetramethylthionine chloride