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MtApproved drug

Methylene blue protocol

Methylene blue is an old dye that the US FDA approves as an IV drug for acquired methemoglobinemia, a blood condition. Low-dose oral use for aging is not approved or proven.

Approved in the US (IV): Provayblue, for acquired methemoglobinemiaNot approved for aging, memory or any oral useBoxed warning: serotonin syndrome with some antidepressants and opioids
ProtocolMixingResultsSide effectsHow it worksSources

The protocol at a glance

The US label dose is 1 mg per kg given into a vein over 5 to 30 minutes. A second dose of up to 1 mg per kg can follow one hour later if needed.

UseAmount
US label, IV1 mg/kg over 5 to 30 minutes
Repeat doseUp to 1 mg/kg one hour later if blood levels stay above 30% or symptoms continue
Moderate or severe kidney problemsOne 1 mg/kg dose only
Not allowedDo not give under the skin
Oral low-dose for agingNot established

From the Provayblue US prescribing information (openFDA, label effective May 2025). The label covers IV use for methemoglobinemia only.

Community reports

Community posts often take 5 to 20 mg by mouth daily for energy or focus. This is community talk, not a labeled use.

What people say they do, collected from community discussions. Not tested in a trial; shown so you can compare it with the evidence above.

Mixing

No mixing table here: this one is used as a capsule, nasal spray or skin product, or has no human amount to calculate from. The general mixing calculator works for any vial.

What the trials found

No human trial shows a longevity benefit. The closest human studies were small:

0trials showing an anti-aging benefit
195 mgoral daily dose in a 6-month bipolar disorder study (37 people); depression and anxiety scores improved versus 15 mg
1 mg/kgIV label dose for methemoglobinemia

Alda M et al. Br J Psychiatry 2017 (PubMed 27284082, NCT00214877); Provayblue US label. Another human study used one low oral dose and looked at brain scans only (PubMed 26961091).

Side effects

  • Boxed warning: it can cause serious or even fatal serotonin syndrome with SSRIs, SNRIs, MAOIs, and opioids.
  • Common effects in label trials: headache, low potassium, diarrhea, low magnesium, muscle twitching, nausea and seizure-like events.
  • It can break down red blood cells and can throw off pulse oximeter readings.

How it works

Oxidation-reduction agent

The label calls it an oxidation-reduction agent and uses it for methemoglobinemia, where blood cannot carry oxygen properly.

MAO inhibitor

It also blocks the monoamine oxidase enzyme, which is why it clashes with antidepressants.

Sources

  • Provayblue (methylene blue) US prescribing information via openFDA, effective 28 May 2025
  • Alda M et al. Methylene blue treatment for residual symptoms of bipolar disorder. Br J Psychiatry 2017, NCT00214877
  • Methylene blue modulates functional connectivity in the human brain. Brain Imaging Behav 2017 (PubMed 26961091)