As with all therapies, use of herbs involves risk. The general public usually takes herbal therapies in the form of supplement pills, not as a preparation made directly from the herb by a trained herbalist. It is also wise to keep in mind that herbal supplements are not as closely regulated as prescription drugs. The amount of the herb used and its quality, safety, and purity may vary among brands or even among batches of the same brand. Herbal therapies may interact with prescription drugs, resulting in dramatic changes in the effect of the botanical, the drug, or both. To be safe, women should tell their healthcare providers about any herbal therapies they are considering and always stop these treatments at least two weeks before any planned surgery.

Additional information about herbal products can be found at:
NIH National Center for Complementary and Alternative Medicine
HerbMed 
As always, much menopause information can be found at the NAMS website.