DHEA

Many companies sell dehydroepiandrosterone (DHEA) and androstenedione. Among the many marketed uses is muscle strengthening. They postulate that these proteins are in the pathway that turns cholesterol into testosterone. Therefore more must be better. These suppliments have been studied for building muscle mass and the results were not worth the risk. Androstenedione or DHEA supplementation was not able to increase strength in tests of single bench press or increase the average strength after 12 weeks of use.

Adverse side effects:
Include increased estrogen. One case of priapism. It can also decrease you healthy cholesterol. It is also illegal in the NCAA and the IOC.

Look for yourself
Broeder CE, Quindry J, Brittingham K, et al. The Andro Project: physiological and hormonal influences of androstenedione supplementation in men 35 to 65 years old participating in a high-intensity resistance training program. Arch Intern Med. 2000;160(20):3093–3104

Wallace MB, Lim J, Cutler A, Bucci L. Effects of dehydro-epiandrosterone vs androstenedione supplementation in men. Med Sci Sports Exerc. 1999;31(12):1788–1792.

Broeder CE, Quindry J, Brittingham K, et al. The Andro Project: physiological and hormonal influences of androstenedione supplementation in men 35 to 65 years old participating in a high-intensity resistance training program. Arch Intern Med. 2000;160(20):3093–3104
Natural Medicines Comprehensive data base DHEA