NOW TestoJack 100 contains a potent standardized extract of Eurycoma longifolia, commonly known as Tongkat Ali or Long Jack. LJ100 contains bioactive Eurypeptides, the active constituents of Tongkat Ali. Studies indicate that Tongkat Ali extracts may support male reproductive function and health testosterone levels. Tribulus has been included for its virility supporting effects as demonstrated in scientific studies. TestoJack 100 also contains ZMA, a unique formula of zinc and magnesium for the support of healthy immune, reproductive and neuromuscular function. This combination of ingredients makes TestoJack 100 the optimal formula for the overall support of mens hormonal health and reproductive function.