Ergostane is a tetracyclic triterpene, also known as 24S-methylcholestane.

The compound itself has no known uses;[citation needed] however various functionalized analogues are produced by plants and animals.

The most important of these are the heavily derivatised withanolides.

[1][2] However simpler forms do exist, such as the sterane campestane (24R-methylcholestane).

Along with cholestane and stigmastane, this sterane is used as a biomarker for early eukaryotes.