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.
The Miracle Belt stemmed in part from athletes' and trainers' use of weights and sandbags to develop proprioception, or body awareness and the engagement of particular muscles, while strengthening balance and coordination.