The internet is abuzz with tributes to a liquid chemical called methylene blue[1] that is being sold as a health supplement.
Over the past five or 10 years, methylene blue has come to be touted online as a so-called nootropic agent[2] – a substance that enhances cognitive function. Vendors claim that it amps up brain energy, improves memory, boosts focus and dispels brain fog, among other supposed benefits.
Health...