Methylene blue

Methylene blue is discussed as a possible cognitive and mitochondrial aid, but its benefits are not certain and it carries meaningful safety risks.

• Historical use: It was described as the first pharmaceutical drug prescribed in the United States, in the late 1800s, and as a treatment still used for carbon monoxide poisoning. 1
• Possible actions: It may support mitochondrial function by shuttling electrons, and it is also described as having mild monoamine oxidase inhibitor (MAOI) activity. 2 3
• Emerging interest: The discussion includes interest in possible use related to COVID-19 and mitochondrial health, while noting that such reports are not proof of benefit. 4
• Oral use: It was described as well absorbed orally, with a suggested dose of no more than about 10 mg, taken in the morning. 5
• Effects and risks: It can turn urine or other fluids blue or green; intravenous use may cause painful vein spasms, and excessive use can stain teeth or skin. 6 7
• Evidence and caution: The discussion mentions small pilot trials and anecdotal reports, but cautions that too much may cause harm, including serotonin syndrome; use calls for care, especially alongside serotonergic medications. 8 9