Testosterone drifts down with age, and chronic stress doesn't help: cortisol, the stress hormone, works against it. Tongkat ali, a root used for generations in Southeast Asia, is one of the few herbs with controlled human trials looking at both sides of that equation.
The studies are small and results vary from man to man, but they point the same way: healthier testosterone levels, lower stress hormones and better strength in older men.
Pro Series gives you 400 mg of concentrated root extract in a single capsule. No proprietary blend. No six-pill serving.