{"hq_id":"hq-c-org-002116","name":"Methylene blue","context":"human_adult","risk_level":"moderate","schema":"legacy","note":"Synthesis unavailable: compound lacks vectorizable regulatory classifications. Raw safety data returned.","data":{"risk_level":"moderate","summary":"Methylene blue is a phenothiazine cationic dye with three distinct use profiles: (1) aquarium therapeutic for fungal and protozoan infections at 2-3 mg/L; (2) FDA-approved IV medication for acquired methemoglobinemia (at low therapeutic doses, 1-2 mg/kg, it reduces met-Hb to functional Hb via NADPH-methemoglobin reductase); and (3) histology stain. Paradoxically causes methemoglobinemia at high doses (>7 mg/kg). MAOI activity makes it contraindicated with serotonergic drugs (serotonin syndrome risk). Hemolysis risk in G6PD-deficient patients. Aquarium use stains silicone seals and ornaments blue persistently; dose carefully and use in hospital tank since it's also harmful to nitrifying bacteria and live plants. Historical use as antimalarial (largely supplanted).","source_refs":["src_pubchem","src_phase59_batch"]},"meta":{"synthesis_version":"n/a","timestamp":"2026-07-27T02:34:45.922Z"},"_notice":"ALETHEIA output is reference data, not professional advice. Not a substitute for primary agency sources or qualified professionals. See https://aletheia.holisticquality.io/disclaimer.","_disclaimer_url":"https://aletheia.holisticquality.io/disclaimer","available_contexts":["human_adult"]}