Rhaponticin is a stilbene glycoside compound found primarily in Rheum rhaponticum (Siberian rhubarb). In recent years, it has been studied for its phytoestrogenic properties, specifically its selective estrogen receptor modulator (SERM)-like activity. Several clinical and preclinical studies have investigated extracts of Siberian rhubarb (ERr 731), which are standardized for rhaponticin content, in the context of menopausal symptom relief.

Research shows that ERr 731 can alleviate menopausal symptoms such as hot flashes and night sweats, effects generally attributed to the phytoestrogenic action of its constituents, including rhaponticin. Mechanistically, rhaponticin and related compounds appear to bind preferentially to estrogen receptor beta (ERβ), rather than estrogen receptor alpha (ERα), which may confer beneficial effects without the risks associated with traditional hormone replacement therapy.

Multiple randomized, placebo-controlled trials and observational studies conducted primarily in Europe support the efficacy of Siberian rhubarb extract in reducing menopausal symptoms, with a good safety profile. However, most studies use whole extracts rather than isolated rhaponticin, so the evidence for rhaponticin itself is mostly indirect. Nonetheless, the scientific rationale and clinical data for the standardized extract are reasonably robust, justifying its use for supporting the estrogen system, particularly in peri- and post-menopausal women.