Menopause: a review of botanical dietary supplements.
We conclude that black cohosh extracts appear to ease menopausal symptoms; ongoing studies funded by the National Institutes of Health (NIH) will provide more definitive safety and efficacy data. Soy isoflavone extracts appear to have minimal to no effect, although definitive conclusions are difficult given the wide variation in product composition and dose. Long-term safety of higher dosage (150 mg/day) soy isoflavone extracts is uncertain.
Am J Med. 2005 Dec 19;118 Suppl 12B:98-108.