NOW TribuJack 100™ contains a potent standardized extract of Eurycoma longifolia, commonly known as LJ100™. It contains bioactive Eurypeptides, the active constituents of Tongkat Ali. Clinical and non-clinical studies have shown that Tongkat Ali extracts support male reproductive function and healthy testosterone levels. Tribulus has been included for its virility supporting effects, as shown in scientific studies. TribuJack 100™ also contains ZMA, a synergistic mix of zinc and magnesium, to support healthy immune, reproductive and neuromuscular function. This unique combination provides enhanced energy and male support, without the anxiety and insomnia that may accompany similar supplements. Our NOW natural and organic Supplements are an effective way to ensure you and your loved ones are getting essential vitamins, minerals and nutrients for daily optimal health. Since 1968, NOW has been making top quality products that are tested to the highest standards to empower people to lead healthier lives. Our promise - what is on the label, is precisely what is in the bottle.