Soy Isoflavones
Soy isoflavones are plant compounds in soybeans, mainly genistein, daidzein and glycitein. Because they resemble estrogen in structure, they are called phytoestrogens.
Also listed as Genistein, Genistin, Daidzein, Daidzin
Hot flashes: a modest benefit with uneven results
A 2012 meta-analysis found about a 21% greater reduction in hot-flash frequency versus placebo. Studies lasted six weeks to twelve months and used a median 54 mg daily, expressed as aglycone equivalents. Results varied substantially across studies; NCCIH describes the overall benefit as potentially small and inconsistent. 1 2
“Hormone balance” is too broad a promise
A review of 47 studies found no significant change in the main estrogen measurements in premenopausal women, although some other hormones and cycle length changed modestly. Postmenopausal estrogen changes were not statistically significant. These measurements do not establish treatment of a hormonal disorder. 3
Modest, variable hormone changes do not establish a general estrogen-restoring effect. 3
Bone density is another research lead
NCCIH considers a beneficial effect on bone density after menopause probable. Bone density is a useful measurement, but that statement does not establish fracture prevention or replace an osteoporosis treatment assessment. 2
A possible benefit concerns postmenopausal bone density; fracture protection is a separate question. 2
Effects by health goal
Open an effect to see the studies behind its rating. Bars show the size of the effect; the letter grades the evidence.
Hair & Skin2 effects
No study is linked to this rating.
No study is linked to this rating.
Women's Hormones3 effects
No study is linked to this rating.
No study is linked to this rating.
Cardiovascular1 effect
No study is linked to this rating.
Bone & Joint1 effect
No study is linked to this rating.
Stress & Mood1 effect
No study is linked to this rating.
All studies
3 publications are linked to Soy Isoflavones, newest first.