I-3-C is indole-3-carbinol (I3C), a phytonutrient found in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, and bok choi. Research suggests that I3C is responsible for many of the health benefits of cruciferous vegetables, by supporting a better balance of estrogen metabolite formation. I-3-C provides antioxidant support for the maintenance of good health.