Methylene blue
Summary
Methylene blue is a synthetic dye and the first synthetic medicine. It acts as a strong oxidizing/reducing agent, particularly affecting mitochondrial disorders.
In healthy respiratory chains, methylene blue reduces ATP production. But in disrupted respiratory chains in Complex I, II, III, or IV of the mitochondria, methylene blue can have a positive effect.
Methylene blue also acts as an MAO-A inhibitor, increasing risk of serotonin toxicity and hypertension, but also acting as an antidepressant and anti-anxiety medication.