Methylene blue is one of the oldest compounds in medicine and one of the newest in longevity. A mitochondrial electron carrier, studied at low doses for cellular energy and cognition β and the only compound on this shelf that has been in the pharmacopoeia since the 1890s. π΅ Methylene Blue Capsules Old drug, new question. What it is, in plain English Mitochondria make energy by passing electrons down a chain. When that chain runs poorly β with age, with illness, under stress β output falls. Methylene blue can accept and donate electrons directly, effectively providing a bypass around a sluggish step. That property is why a 19th-century textile dye ended up in modern research on brain energy metabolism. How it helps π Acts as an alternative electron carrier in mitochondria π§ Studied for memory and cerebral oxygen consumption π§ͺ A century-long safety record at pharmaceutical doses π Oral capsule β no needle, no mixing Why people reach for it Interest in methylene blue sits alongside NAD+ for the same reason: both are aimed at mitochondrial output rather than at a hormone or an appetite signal. People already running NAD+ often add it as the second lever on the same system. NAD+ Methylene Blue Target NAD+ pool and sirtuin signalling Electron transport chain directly Route offered here Injection, patch, sublingual, nasal Oral capsule Research base Modern, still emerging Over a century of clinical use Two things worth knowingMethylene blue stains β it will tint urine blue-green, and it can stain the mouth if a capsule is opened. More importantly, it has meaningful serotonergic activity, which is the reason for the interaction warning below rather than a theoretical caution. Is it a fit? Methylene blue suits an interest in mitochondrial function and cognition, particularly alongside NAD+. Anyone on an antidepressant should treat the warning below as a hard stop until a provider has reviewed it. Take the 60-second peptide quiz or message our team, and our providers can point the way. π¬ For the science-minded Methylene blue (methylthioninium chloride) is a redox-cycling phenothiazine that can shuttle electrons to cytochrome c, bypassing complexes IβIII. Low-dose research has examined effects on cerebral metabolic rate, memory consolidation and mitochondrial function; at high doses the redox behaviour reverses and becomes pro-oxidant, which is why the low-dose window matters. It is also a potent monoamine oxidase inhibitor. Methylene blue is a monoamine oxidase inhibitor and can cause serotonin syndrome when combined with SSRIs, SNRIs, MAOIs, triptans or other serotonergic drugs. It is also contraindicated in G6PD deficiency. Anyone taking an antidepressant must clear this with a provider before starting. Educational only β not medical advice. Peptides discussed here are research compounds; whether any is appropriate is a decision between a patient and their licensed provider.