Methylene Blue
Supplement Dosage
Oral methylene blue is dosed as a flat daily amount, not as a calculation against your body weight. Start at 5mg per day, hold for at least a week, then move to 10mg per day and stay there. 20mg per day is the routine ceiling. Here is the schedule, and an honest account of how much evidence sits behind it.
Three Numbers, One Schedule
5mg/day — hold at least 7 days
Take 5mg in the morning with food. This is the entry dose for everyone — it does not scale with how much you weigh. The week is for assessing tolerance: GI comfort, headache, sleep. Blue-green urine is normal and expected, and is not a signal to change anything. If anything else shows up, hold longer or stop.
10mg/day — hold 14 days, then stop titrating
After a well-tolerated week at 5mg, move to 10mg per day. This is the destination, not a waypoint — there is no scheduled step above it. It is also the serving size most methylene blue capsules on the market are sold at, which means it is a dose you can actually buy and repeat without splitting anything.
20mg/day — routine upper bound
20mg per day is the routine ceiling, and it does not move for heavier or more experienced users. Be clear about what this number is: editorial judgment anchored to what is actually sold as a daily serving, not a threshold from a study. For the titration laid out against dates, use our interactive dosage calculator.
How Much Evidence Is Behind This
No published randomized controlled trial has tested chronic daily oral methylene blue in healthy adults for cognitive or mitochondrial endpoints. The 5–10mg schedule above is an extrapolation, and so is every competing number you will find on a supplement site — most just don't say so.
What the human oral literature does establish is narrower and worth knowing:
- •Oral methylene blue has roughly 72% absolute bioavailability in healthy adults (Walter-Sack et al., 2009, European Journal of Clinical Pharmacology).
- •10mg orally is well absorbed in healthy men (DiSanto & Wagner, 1972, Journal of Pharmaceutical Sciences).
- •Single large oral doses produce measurable cognitive effects — a 280mg dose improved memory-retrieval accuracy by about 7% versus placebo in 26 healthy adults (Rodriguez et al., 2016, Radiology). That is 28 times the 10mg target, and does not transfer to a daily capsule.
- •Chronic oral dosing at far higher amounts (69–228mg/day for 24 weeks) was tolerated in an elderly patient population (Wischik et al., 2015).
None of that adds up to a validated daily dose for a healthy adult. It adds up to a defensible place to start and a reason not to climb.
Why Capsules for Dosing
Liquid drops require measuring each dose with a dropper — and dropper accuracy varies by 10-25% depending on angle, speed, and viscosity. Over a 90-day protocol, that variability compounds into inconsistent dosing that makes it difficult to evaluate whether the supplement is working.
Capsules eliminate that variable entirely. A fixed-dose capsule delivers the same milligrams every day with nothing to measure, and because the schedule here is a flat 5mg then 10mg, a 5mg and a 10mg capsule cover the whole titration without splitting anything. For a detailed breakdown of format trade-offs, see our complete guide to taking methylene blue.
Safety Considerations
- !MAOIs and SSRIs: Never combine methylene blue with monoamine oxidase inhibitors or selective serotonin reuptake inhibitors. Methylene blue inhibits MAO-A, creating serotonin syndrome risk — a potentially life-threatening condition.
- !G6PD Deficiency: Individuals with glucose-6-phosphate dehydrogenase deficiency should avoid methylene blue entirely. It may trigger hemolytic anemia in G6PD-deficient individuals.
- !No weight scaling: Do not adjust the dose up or down for your body weight. Every human oral study used a flat fixed dose. The mg/kg figures quoted elsewhere are intravenous clinical doses (the methemoglobinemia antidote is 1-2 mg/kg IV) or rodent injection doses, and neither converts into an oral supplement amount.
- !Know which threshold you are reading: serotonin toxicity has no established safe floor and is categorical with any serotonergic drug; paradoxical methemoglobinemia is documented at 7 mg/kg or more of cumulative intravenous methylene blue; G6PD hemolysis can occur at any dose; and the “dose reversal” effect quoted online comes from rats injected with roughly 50 mg/kg. Four different endpoints, four different routes — not one toxic number.
Frequently Asked Questions
What is the right methylene blue supplement dosage?+
Start at 5mg per day, taken in the morning with food, and hold there for at least 7 days. If it is well tolerated, move to 10mg per day — that is the target, not a step toward something larger, and it matches the serving size most capsules on the market are sold at. Hold 10mg for 14 days and stop titrating. 20mg per day is the routine ceiling. These are flat doses: oral methylene blue is not scaled to body weight.
Is methylene blue dosed by body weight?+
No. Every human oral study of methylene blue used a flat fixed dose. The mg/kg numbers that circulate in dosing guides come from intravenous clinical medicine — the methemoglobinemia antidote is 1-2 mg/kg IV — or from rodent injection studies. Neither converts into an oral supplement dose. Use the same 5 / 10 / 20mg schedule regardless of what you weigh.
Can you take too much methylene blue?+
Yes, but the numbers people quote usually describe four unrelated things. Serotonin toxicity has no established safe floor and is categorical with any serotonergic drug — SSRIs, SNRIs and MAOIs are an absolute no. Paradoxical methemoglobinemia is documented at 7 mg/kg or more of cumulative intravenous methylene blue, and severe hemolysis at 20 mg/kg IV. Hemolysis in G6PD deficiency can occur at any dose, which is why G6PD deficiency is a contraindication rather than a dosing question. The 'dose reversal' effect quoted in biohacker writeups comes from rats injected with roughly 50 mg/kg and is not a human oral number. For daily oral use, 20mg is the routine ceiling.
How much evidence is behind a 5-10mg daily dose?+
Less than most dosing guides imply, and this is worth stating plainly: no published randomized controlled trial has tested chronic daily oral methylene blue in healthy adults for cognitive or mitochondrial endpoints. The 5-10mg range is an extrapolation. What human oral data does establish is that oral methylene blue is about 72% absolutely bioavailable (Walter-Sack et al., 2009), that 10mg orally is well absorbed in healthy men (DiSanto & Wagner, 1972), and that far higher chronic oral doses were tolerated over 24 weeks in an elderly patient population (Wischik et al., 2015). The 20mg ceiling is editorial judgment anchored to market serving sizes, not a study result.
Methylene Blue Ultra launches Q3 2026
USP 99.9% purity, capsule format, no blue staining. Join the waitlist for preferred pricing at launch.