It Works: The ingredients that comprise this formula are second to none. LongJack 400 Complex uses LJ-100, the finest longjack extract available anywhere that supplies 22% EuryPeptides, 40% glyco saponins and 30% polysacharides, to increase free testosterone levels. This compound has been shown, in human clinical trials, to almost double testosterone, increase free testosterone (the testosterone level that is most important), decrease Sex Hormone Binding Globulin (SHBG) (the compound that binds to testosterone to keep it in the unusable state), and increase IGF1 levels. The Test-Stim Complex includes a variety of ingredients that help to elevate both of your testosterone levels: free and total. Universal Nutrition use only the best tribulus that is standardized for 60% steroidal saponins as well as 20% protodioscin, which helps to elevate luteinizing hormone (LH). LH, in turn, raises your total testosterone levels. Finally, avena sativa is standardized for avenacosides A & B, and helps to break bound testosterone off of compounds that keep it from entering into free systemic circulation. With this increase in both total and free testosterone, your strength and drive in the gym will follow, leading to superior lean muscle mass gains