Metagenics, San Clemente, CA, has introduced Estrovera—an all-natural dietary supplement formulated to address the needs of menopausal women—to the North American market. The key active ingredient in Estrovera is ERr 731, a phytoestrogen extract of Siberian rhubarb root.

In a randomized, double-blind, placebo-controlled study of 112 perimenopausal women with menopausal symptoms, subjects who took 4 mg of ERr 731 (equivalent to one Estrovera tablet) daily for 12 weeks experienced a statistically significant reduction in hot flashes per day (12 at baseline and 2 at study end) vs. placebo (12 at baseline and 13 at study end). The product also demonstrated a statistically significant improvement vs. placebo in all 11 menopausal symptoms in the Menopause Rating Scale (MRS), a validated measurement tool to evaluate hormone and natural therapies.

The mechanism of action of ERr 731 in Estrovera may be attributed to the presence of hydroxystilbenes, a type of phytoestrogen that acts as a selective estrogen receptor modulator, or SERM, and which can be found in high concentrations in Siberian rhubarb. SERMs are compounds that may deliver the benefits of estrogen without its side effects.

ERr 731 was first introduced in 1993 in Germany, where it continues to be widely recommended by healthcare providers. It is one of the most thoroughly researched natural compounds for managing menopausal symptoms, according to Metagenics.