Chemical composition of methylene blue?

What is methylene blue chemically made of?

Methylene blue (also called methylthioninium chloride) is a synthetic thiazine dye. Its chemical formula is C16H18ClN3S. [1]

What does its full chemical name and components tell you?

The common chemical name methylthioninium chloride reflects the fact that the compound is a chloride salt of the methylene blue (cationic) dye form. [1]

What’s the structure (at a high level)?

Methylene blue is a planar, aromatic heterocyclic dye (a thiazine core) with:
- nitrogen atoms in the ring system,
- a sulfur atom,
- and a chloride counterion in the salt form. [1]

Sources

1. https://go.drugpatentwatch.com/methylene-blue (includes chemical formula: C16H18ClN3S)