(S)-2,3-Oxidosqualene ((S)-2,3-epoxysqualene) is an intermediate in the synthesis of the cell membrane sterol precursors lanosterol and cycloartenol, as well as saponins.

It is formed when squalene is oxidized by the enzyme squalene monooxygenase.

2,3-Oxidosqualene is the substrate of various oxidosqualene cyclases, including lanosterol synthase, which produces lanosterol, a precursor to cholesterol.

[1] The stereoisomer (R)-2,3-oxidosqualene is an inhibitor of lanosterol synthase.