The exact mechanism of action is unknown, but doctors Michael Zeligs and Scott Connelly state in their book, “All About DIM,” that some of the benefits are likely derived from the fact that DIM helps to balance the sex hormones estrogen and testosterone. They explain that when estrogen is broken down in your body, it can either form beneficial or harmful estrogen metabolites, and DIM helps your body to break down estrogen into the beneficial type. The beneficial estrogen metabolites have antioxidant properties and help to protect the heart and brain from free-radical damage. Diindolylmethane also simultaneously reduces the levels of harmful estrogen metabolites, which is beneficial because they are associated with an increased risk for obesity, breast cancer and uterine cancer. Additional problems associated with too many harmful estrogen metabolites include moodiness and breast pain in women and loss of sex drive in men.
Diindolylmethane also appears to promote a healthy balance of testosterone in the body. Testosterone supports energy, promotes a happy mood and helps to maintain a healthy sex drive. In addition, Zeligs states that DIM may have an anti-aging effect and may help encourage lean body mass. When combined with exercise, it can increase muscle mass. These benefits are speculative, however, and more research needs to be done to confirm the efficacy of these claims.