(20S)-ginsenoside Rg3 is a ginsenoside found in Panax ginseng and Panax japonicus var. major that is dammarane which is substituted by hydroxy groups at the 3beta, 12beta and 20 pro-S positions, in which the hydroxy group at position 3 has been converted to the corresponding beta-D-glucopyranosyl-beta-D-glucopyranoside, and in which a double bond has been introduced at the 24-25 position. It has a role as an antineoplastic agent, an angiogenesis modulating agent, an apoptosis inducer and a plant metabolite. It is a glycoside, a tetracyclic triterpenoid and a ginsenoside. It is functionally related to a (20S)-protopanaxadiol. It derives from a hydride of a dammarane.