- Estrogen is a sex hormone responsible for the development and regulation of the reproductive system and secondary sex characteristics. They also play a critical role in the development of breast and uterine cancer. The formation of agonistic metabolites of estrogen, especially 16α-hydroxyestrone, have been found to have cancer-inducing effects meanwhile other estrogen metabolites, such as 2-hydroxyestrone, have been found to serve as an anti-estrogen and The urinary ratio of 2-hydroxyestrone to 16α-hydroxyestrone has been used as a biomarker for estrogen-related cancer risk and lower ratios have been correlated with reduced cancer risk. Diets rich in cruciferous vegetables, such as Brussel sprouts, broccoli, cauliflower, and kale, have shown chemopreventive properties in preclinical cancer models and clinical trials. The active components of cruciferous vegetables, indole-3-carbinol (I3C), or 3,3’-diindolylmethane (DIM) is able to induce the CYP1A1 enzyme that catalyzes the formation of 2-hydroxyestrone in the body. This study was conducted to assess the effects of Brussels sprouts and DIM supplements on estrogen levels, specifically 2-hydroxyestrone and 16α-hydroxyestrone, to evaluate preventative treatment against cancer risk. Participants in this study were given either Brussels sprouts or DIM supplements. Urine samples were collected and analyzed for their estrogen profiles. The data did not demonstrate that Brussels sprouts or DIM supplementation led to a lower urinary ratio by inducing the CYP1A1 enzyme to promote 2-hydroxyestrone formation.