Also marketed as fat burners, thermogenics are designed to raise your body’s internal temperature and speed up your metabolism. In theory, a faster metabolism increases the amount of calories you burn, which could induce faster weight- or fat-loss. Common ingredients thought to be thermogenic include cayenne pepper, green tea, yohimbine, coffee bean extract, garcinia cambogia, synephrine and caffeine. Many thermogenic formulas also contain ingredients said to suppress the appetite – such as glucomannan. Thermogenics are widely thought to be companions to exercise, rather than alternatives. These products usually contain caffeine, so you may wish to proceed with caution if you are sensitive to stimulants.