Solaray Blue Cohosh has 500 mg in each vegetarian capsule.  Blue Cohosh is a highly regarded herb for females, especially for women under 40.  Solaray guarantees that no ingredients other than those listed on the label have been added to this product.
Caulophyllum Thalictroides
Green Screened - From the Wild
Vegetarian Capsules
If painful periods are a problem, take the herb blue cohosh (Caulophyllum thalictroides), two capsules twice a day for a month. If this seems to help, continue the treatment for another month, then cut the dose in half and gradually reduce it to nothing.