I am 29 years old and have been into weightlifting/ powerlifting for a decade. Tribex has worked for boosting the aggressiveness and intensity of my workouts. I have noticed that I recover faster and can do more reps and sets now. The only negative is that it causes me to have slight headaches, and will keep me awake if I take it too close to bed time. I wouldn't suggest this product for anyone under 25 because your testosterone levels are already high, and I would definitely use it in cycles as directed. It is slightly pricey, but an effective alternative for guys wanting a natural boost. I haven't noticed any changes in libido.