Genistein
Genistein is an isoflavone, a plant compound found mainly in soybeans that can bind to estrogen receptors.
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
What is genistein?
Genistein is a soy isoflavone, a plant compound that interacts with estrogen receptors. Laboratory studies show a preference for one receptor subtype, but responses vary by tissue and context. That biology helps explain the research interest without predicting a uniform effect throughout the body. 1
Key studies
The most recent publications linked to Genistein's ratings.
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Does genistein balance estrogen?
It interacts with estrogen receptors, but responses depend on biological context. “Balance” is too broad to describe those effects or the outcomes measured in trials. 1
Does it prevent broken bones?
The two-year trial found improved bone density but did not measure fractures. Fracture protection remains a separate unanswered question. 2
Did hot flashes keep improving for two years?
In the symptomatic subgroup, the improvement at 12 months did not increase further by 24 months. 3
What does the German safety guidance say?
BfR cites up to 100 mg daily of soy isoflavones for up to ten months as a guide for healthy postmenopausal women. This is neither a treatment dose nor a universal limit for pure genistein. Higher doses and longer use remain insufficiently assessed. 4