Methylene Blue
A synthetic dye and FDA-approved drug, used off-label as a low-dose oral supplement; tracked as a supplement-type item.
Methylene blue (methylthioninium chloride) is a synthetic phenothiazine dye first made in 1876. It is an FDA-approved injectable medicine for acquired methemoglobinemia and, separately, is sold as a low-dose oral supplement on the strength of research into mitochondrial electron transport. It is a small molecule, not a peptide: nothing is reconstituted and it is taken by mouth as a solution or capsule.
Dosing units. Protocols are written per kilogram of body weight, and bottles are labelled as a percentage: a 1% solution is 10 mg/mL, so a dose in mg ÷ 10 = mL, and a nominal 0.05 mL drop carries about 0.5 mg. The dosing math guide walks the conversions with a calculator.
Safety facts from the label. The approved product carries a boxed warning for serotonin syndrome when combined with serotonergic drugs (SSRIs, SNRIs, tricyclics, MAOIs and others), is contraindicated in G6PD deficiency, and turns urine blue-green. Grade matters too: only USP (pharmaceutical) grade is manufactured to pharmacopeia purity. Suppliers such as GoBlueBrain sell USP-grade product; ask any source for a certificate of analysis.
In PeptideWiz, methylene blue is tracked as a supplement-type item with the dose in mg, its own schedule and reminder, and its own side-effect log, so it stays attributable next to any peptides or GLP-1 on the same routine. See tracking methylene blue with peptides & GLP-1s.
Not medical advice. PeptideWiz is a tracking and organization tool. These definitions are general education only — not medical advice, a recommendation, or instructions for use. Always work with a licensed medical provider.
Frequently asked questions
What is methylene blue?
Methylene blue is a synthetic phenothiazine dye first produced in 1876. It is FDA-approved as an injectable medicine (ProvayBlue) for acquired methemoglobinemia, and it is also sold as a low-dose oral supplement. It is a small molecule, not a peptide, so it is taken by mouth rather than reconstituted and injected.
How is methylene blue dosed?
By body weight, in milligrams per kilogram, from a solution labelled as a percentage: a 1% solution is 10 mg/mL. The approved injectable is labelled at 1 mg/kg for its approved use; oral research doses span a wider range. PeptideWiz does not recommend a dose; the dosing math guide only shows how to convert whatever your provider specifies into mL or drops.
What are the main safety warnings for methylene blue?
The FDA-approved label carries a boxed warning for serotonin syndrome when methylene blue is combined with serotonergic drugs such as SSRIs, SNRIs, tricyclics and MAOIs, and it is contraindicated in G6PD deficiency because it can cause hemolytic anemia. See the FDA safety communication. Whether it is appropriate for you is a question for a licensed provider.
Why does methylene blue turn urine blue or green?
It is excreted largely unchanged in urine, so blue-green urine (and sometimes stool) is an expected, harmless effect noted on the product label. It also stains skin, teeth and surfaces, which is why people dilute it and use a straw.
How do I track methylene blue in PeptideWiz?
Add it as a supplement-type item with the dose in mg, put the solution concentration in the directions, give it its own schedule and reminder, and log side effects against the item so they stay separate from any peptides or GLP-1 you also track.