Up to now, little is known about the safety of regular or long-term use of diindolylmethane powder supplements. Because diindolylmethane may affect estrogen metabolism. There are concerns that taking diindolylmethane supplements will aggravate hormone-sensitive diseases such as endometriosis and uterine fibroids.

According to a report, a healthy woman developed a condition that caused visual impairment after taking diindolylmethane in excess daily for two months. After stopping the supplement, her symptoms disappeared after eight weeks. After the use of diindolylmethane, a rash with eosinophilia was reported. Muscle and joint pain also occurs especially hip and knee pain.

After menopause, the female body produces less estrogen. So DIM may not have many benefits. In the worst case, DIM may reduce the body's ability to maintain healthy bone density, which can further lead to osteoporosis-thinning of bones.

Considering safety issues, it is very important to seek medical advice before using diindolylmethane powder supplements. Women who are pregnant or breastfeeding should not take it. In addition, people who are undergoing cancer treatment should not take it.