SHEET /m/methylene-blue · PubChem CID 6099 · CAS 61-73-4 · REV 2026.07
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Methylene blue
from sourceC16H18ClN3S · 319.9 g/mol
methylthioninium chloride · methylenium ceruleum · Swiss blue · Ehrlich's reagent III
What is Methylene blue?
A deep blue thiazine dye that doubles as a medicine for methemoglobinemia. It stains cells for the microscope, treats fish tanks, and turns urine green. from source
CategoryPrescription medicine
Fig. 1 · 2D structure RDKit
SMILES
CN(C)C1=CC2=C(C=C1)N=C3C=CC(=[N+](C)C)C=C3S2.[Cl-]Where you'll find it
Dispensed on prescription, not sold on a shelf. See the rest of the prescription medicine group.
Relative acute toxicity from source
Animal study data · LD50
- Reported LD50
- 3,500 mg/kg · very low toxicity
- Species
- mouse
- Route
- oral
An LD50 describes acute toxicity under experimental conditions and is not a safe or dangerous dose for a person.
Toxicity & hazards
Toxicity · LD50
3,500 mg/kg · very low toxicity · LD50 mouse oral from source
3 more reported values
- 77 mg/kgLD50 · iv · mouse
- 150 mg/kgLD50 · other · mouse
- 1,250 mg/kgLD50 · iv · rat
DangerCorrosiveIrritantHealth hazardH302, H318, H361, H370, H372, H412from source