Diindolylmethane (DIM) is a compound formed in the body during the digestion of indole-3-carbinol, which is found in cruciferous vegetables such as broccoli and Brussels sprouts. There is a moderate level of scientific evidence supporting its use for prostate health. Preclinical studies and some small human trials suggest that DIM may help support healthy estrogen metabolism and exert anti-androgenic effects, which can be beneficial for the prostate. Specifically, DIM has demonstrated the ability to inhibit the proliferation of prostate cancer cells in vitro and in animal models, potentially through modulation of hormone pathways and induction of apoptosis.

Some human studies indicate that DIM supplementation may improve urinary symptoms related to benign prostatic hyperplasia (BPH) and help balance hormone levels, though these studies are generally small and not always rigorously controlled. There is also interest in DIM’s potential to prevent the development or progression of prostate cancer, but large-scale clinical trials are lacking. Overall, while laboratory and early clinical data are promising, more robust human research is needed to firmly establish efficacy for prostate health. Therefore, DIM's use for supporting the prostate is based on a reasonable scientific foundation but is not yet conclusively proven.