Brain boost? Mitochondrial support? Longevity tool? Here’s what you actually need to know. Methylene blue has been around for well over 100 years, but lately it has exploded in the longevity and biohacking world. So what exactly is it? 🔵 Methylene blue is a synthetic compound and medication — NOT a peptide. Its established medical use includes treating acquired methemoglobinemia, a condition in which hemoglobin can't effectively deliver oxygen to tissues. But the reason you're hearing about it in the wellness world is very different: 🧠 Why are people interested in it? Researchers have studied methylene blue's effects on mitochondrial energy metabolism and the brain. At low concentrations, laboratory and preclinical research suggests it can participate in electron transfer within mitochondria—the little “power plants” inside our cells. That's where the interest in energy, cognition, memory and neuroprotection comes from. There is some human research too. One small randomized, double-blind study involving 26 healthy adults investigated a single low oral dose and found changes in brain activity associated with attention and memory, along with improved memory retrieval. Interesting? Yes. Proof that taking methylene blue long-term prevents cognitive decline or acts as a longevity drug? No. And larger Alzheimer's research using a related form of the methylene-blue molecule has not demonstrated the clear benefit people sometimes imply online. A Phase 3 trial involving 891 people did not meet its primary efficacy outcomes when the treatment was added to standard Alzheimer's medications. 🚨 THIS PART MATTERS: Who should NOT casually take it? Methylene blue can act as a monoamine oxidase (MAO) inhibitor, which means medication interactions can become serious. ⚠️ SSRIs/SNRIs and other serotonergic antidepressants ⚠️MAO inhibitors ⚠️Certain opioids ⚠️Dextromethorphan— found in many cough medicines ⚠️ Other medications that increase serotonin Combining methylene blue with serotonergic drugs can potentially cause serotonin syndrome, which can be life-threatening. The current prescription label carries a boxed warning about this interaction.