# Methylene blue pharmacokinetics: human study comparison

Study doses identify the experiments and are not instructions for use. MB means methylene blue. Half-life estimates depend on analyte, sample compartment, assay, and sampling window.

| Evidence | Route and population | Analyte, sample, and method | Sampling and reported result |
| --- | --- | --- | --- |
| Peter et al., 2000 | 100 mg IV and oral; seven volunteers | MB in whole blood; high-performance liquid chromatography | Blood profile through 4 hours, as tabulated by FDA; IV terminal half-life 5.25 hours |
| Walter-Sack et al., 2009, IV arm | 50 mg IV; 16 healthy adults enrolled, 15 completed crossover | MB in plasma and whole blood; chromatography with tandem mass spectrometry | Repeated samples through 24 hours; mean half-life 18.5 hours in plasma and 13.6 hours in whole blood |
| Walter-Sack et al., 2009, oral arm | 500 mg aqueous oral formulation; same crossover population | Same analyte, compartments, and assay | Samples through 24 hours; mean half-life 18.3 hours in plasma and 14.7 hours in whole blood; mean plasma Tmax 2.2 hours |
| FDA review, 2016, injection development studies | Single IV exposure in healthy volunteers; review summarizes a 2 mg/kg, five-minute infusion | MB and Azure B measured separately in whole blood and plasma by liquid chromatography with tandem mass spectrometry | Measurements extended to 72 hours; review describes an approximately 24-hour terminal MB half-life |

The FDA review's approximate 24-hour summary is not a claim that every analyte and compartment has the same half-life. Azure B is measured separately. These estimates do not establish complete clearance, daily-use safety, a washout interval, or onset of cognitive effects.

Sources inspected:

1. [Peter et al., Pharmacokinetics and organ distribution of intravenous and oral methylene blue](https://pubmed.ncbi.nlm.nih.gov/10952480/).
2. [Walter-Sack et al., High absolute bioavailability of methylene blue given as an aqueous oral formulation](https://www.researchgate.net/publication/23273151_High_absolute_bioavailability_of_methylene_blue_given_as_an_aqueous_oral_formulation).
3. [FDA clinical pharmacology review, NDA 204630](https://www.accessdata.fda.gov/drugsatfda_docs/nda/2016/204630Orig1s000ClinPharmR.pdf).

Prepared 12 September 2026. Companion article: /en/articles/methylene-blue-half-life-in-the-body/.