(S)-codamine is a benzylisoquinoline alkaloid that is 1,2,3,4-tetrahydroisoquinolin-7-ol which is substituted by 3,4-dimethoxybenzyl, methyl, and methoxy groups at positions 1, 2, and 6, respectively (the 1S enantiomer). It is a benzylisoquinoline alkaloid, a benzyltetrahydroisoquinoline, a member of phenols, an aromatic ether and a tertiary amino compound. It is a conjugate base of a (S)-codamine(1+).