Supplements increase caloric expenditure for several hours and might be useful as a weight-loss supplement. Capsaicin works by increasing levels of the “fight-on-flight” hormone epinephrine (adrenaline), which speeds fat use and increases metabolism. Canadian researchers found that capsaicin was effective in the treatment of prostate cancer. Capsaicin sensitizes prostate cancer cells, so that they require lower radiation doses during treatment of the disease. It also suppressed prostate cancer cell growth in cell colonies cultured in the laboratory.