Cruciferous vegetables, including broccoli, cauliflower, Brussels sprouts, and cabbage, contain a compound called indole-3-carbinol (I3C).* As a nutritional supplement, I3C provides key nutritional support for the liver's detoxification of estrogens, thus playing an important role in supporting female reproductive health.* A large portion of I3C is converted to diindolylmethane (DIM), the substance believed to be the primary contributor to I3C's beneficial properties. DIM has been shown to selectively bind to estrogen receptors and might act as an estrogen antagonist.*

In the liver, I3C promotes the metabolism of estrogen and increases the ratio of 2-hydroxy estrogen to 16-hydroxy estrogen.* The 2-hydroxy estrogens, which are less active than the 16-hydroxy estrogens, are generally eliminated more quickly from the body. One study found postmenopausal women who had the most favorable 2:16-hydroxy estrogen ratio were most likely to maintain good female health.* Studies have examined the efficacy, safety, and optimal supplementation of I3C. A 12-week trial conducted on 17 women found a 66-percent increase in the 2:16-hydroxy estrogen ratio with administration of 400 mg of I3C daily.*