Tongkat ali also called longjack is a supplement that comes from the roots of the tree Eurycoma. It contains the active glycoprotein compounds: eurycomanone, eurycomalactone and eurycomanol. This supplement may be used by men to increase testosterone levels and improve fertility. It’s been claimed that Longjack can boost athletic performance, reduce fatigue , improve endurance and boost muscle mass. It contains compounds which help the body use more energy, and use it more efficiently. It has also shown to reduce anxiety as it decreases tension and confusion.