Tribulus terrestris is the #1 selling testosterone booster, and the best example of a supplement that increases libido, but has no effect on testosterone.
Ab belts may cause muscle contractions if used properly. But the belt alone cannot produce six-pack abs. The real challenge to ab definition is the layer of fat that lies right under the skin, hiding muscle tone.
Exercise your midsection. Jupiterimages/Polka Dot/Getty Images. The manufacturer claims that the Slendertone toning belt offers a way to help you tone your abdominal muscles using electronic muscle stimulation.