PROVAYBLUE (methylene blue) injection, for intravenous use: FDA-approved prescribing information, including boxed…
I am taking methylene blue (or thinking about it) while on an antidepressant — given the FDA boxed warning about fatal serotonin syndrome, is there any dose of this that is safe for me?
Well-supported by good-quality research. how we score evidence
Methylene blue is an FDA-approved drug, but only for one thing: ProvayBlue (methylene blue injection, NDA 204630, Provepharm) is indicated for the treatment of pediatric and adult patients with acquired methemoglobinemia.
FDA-approved labeling states that methylene blue is indicated only for acquired methemoglobinemia and carries a boxed warning that it "may cause serious or fatal serotonergic syndrome when used in combination with serotonergic drugs and opioids", instructing prescribers to avoid concomitant use with SSRIs, SNRIs, MAOIs, and opioids. The labeling attributes this to methylene blue being a potent reversible inhibitor of monoamine oxidase, and notes that some reported cases were fatal.
Worth asking
I am taking methylene blue (or thinking about it) while on an antidepressant — given the FDA boxed warning about fatal serotonin syndrome, is there any dose of this that is safe for me?
Source
PROVAYBLUE (methylene blue) injection, for intravenous use: FDA-approved prescribing information, including boxed warning for serotonin syndrome with concomitant serotonergic drugs and opioids. — US Food and Drug Administration. (2025)
Regulator or national health body
Read the source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/204630s021lbl.pdf
How this was scored
- Study design
- Regulatory safety determination
- Funding
- No external funding
- Published in
- Regulator or national health body
- Sample size
- not recorded
- Preregistered
- No
- Conflicts disclosed
- No
- Independent of proponent
- Yes
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 19, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "strong evidence". Well-supported by good-quality research. It scores 82 out of 100 on our published rubric. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
PROVAYBLUE (methylene blue) injection, for intravenous use: FDA-approved prescribing information, including boxed warning for serotonin syndrome with concomitant serotonergic drugs and opioids. — US Food and Drug Administration. (2025). Published in: Regulator or national health body. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Regulatory safety determination. Funding: No external funding. The researchers were independent of whoever benefits from the result. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is methylene-blue, provayblue, methylthioninium chloride, methylene blue usp, mb FDA approved for this use?
No. Its current status is: Not FDA-evaluated for this use. Methylene blue is an FDA-approved drug, but only for one thing: ProvayBlue (methylene blue injection, NDA 204630, Provepharm) is indicated for the treatment of pediatric and adult patients with acquired methemoglobinemia.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.