As we age, the body’s ability the produce testosterone decreases. In fact, after the age of 27, most men experience a gradual decline in the hormone. A testosterone booster is a natural supplement that aims to increase your testosterone levels naturally. Testosterone boosters work by increasing testosterone within a normal range, providing all the benefits a healthy testosterone level can achieve, such as lean muscle gain and strength as well as aiding in fat loss, libido and energy levels. A safe alternative to anabolic steroids, testosterone supplements can be used for bulking, cutting and enhancing overall performance.