What it does, plainly. Inside your cells, mitochondria pass electrons down a chain to make ATP, your body's energy currency. Methylene blue is one of the few things you can swallow that joins that chain directly, lifting complex IV activity about 30% and oxygen use by more than a third ¹. It also mops up the stray electrons that would otherwise become damaging free radicals, and keeps doing it without being used up ².

The human read. Twenty-six healthy adults on a single dose recalled 7% more and lit up more of their attention circuitry on a scanner an hour later ³. In bipolar patients already on mood stabilisers, it eased residual depression and anxiety ⁴, ⁵. The big Alzheimer's bet went the other way: a related derivative failed its phase 3 trial across thousands of patients ⁶.

Screen yourself before you dose. Both screens are hard gates.

Expect bright blue-green urine and a blue tongue for an hour or two. Both are harmless. Surfaces and clothing stain semi-permanently, so mind where the bottle goes.

What you actually feel. An hour after a low dose, an attention task you would have drifted through goes a little cleaner. No jitter, no crash, no racing heart — it reads less like coffee and more like your brain on a good night's sleep. The scanner data back the felt version: real activation in the regions that run sustained attention and recall, for a few hours ³.

• Same day: the bump is acute. Skip a dose and it isn't there.
• Over a month: the average day looks a touch sharper, but not dramatically.
• Years out: cell and animal work hints it slows mitochondrial decline ¹, but no human trial has run long enough to prove that.