Rationale A large body of evidence supports the role of dietary factors in prostate cancer development and progression. Most of this evidence suggests that diet high in fat including red meat and low in micronutrients and other anti-oxidants, increases the risk of disease. We are interested in the therapeutic potential of the dietary agent, capsaicin (CAP). Capsaicin is the active compound in chili peppers, and related plants. Pre-clinical studies have found that capsaicin has potent growth inhibitory and pro-apoptotic effects. It is thought that consumption of a capsaicin supplement may have a clinical benefit for subjects with localized prostate cancer who have chosen to be managed by active surveillance or improve surgical outcome of patients undergoing radical prostatectomy.