If a man's testosterone looks below the normal range, there is a good chance he could end up on hormone supplements—often indefinitely. "There is a bit of a testosterone trap," Dr. Pallais says. "Men get started on testosterone replacement and they feel better, but then it's hard to come off of it. On treatment, the body stops making testosterone. Men can often feel a big difference when they stop therapy because their body's testosterone production has not yet recovered."
The testosterone supplements are primarily used to enhance the body muscle mass. Various studies have shown that testosterone therapy is also crucial in development of the memory as well as concentration, increase the level of energy, and increase libido or sexual desire. However, use of high levels of testosterone booster can also contribute to the development of certain medical conditions and health problems. Two types are available on the market, legal boosters, and illegal boosters. There are also certain excellent natural testosterone boosters that are efficient and so not have side effects.
The natural production of DHEA is also age-dependent. Prior to puberty, the body produces very little DHEA. Production of this prohormone peaks during your late 20’s or early 30’s. With age, DHEA production begins to decline. The adrenal glands also manufacture the stress hormone cortisol, which is in direct competition with DHEA for production because they use the same hormonal substrate known as pregnenolone. Chronic stress basically causes excessive cortisol levels and impairs DHEA production, which is why stress is another factor for low testosterone levels.
There are numerous studies that show that Tribulus does not increase testosterone levels, and provides no assistance in increasing muscle mass or strength. I one of the two group of rugby players were put on the herb or a placebo. At the end of the experiment, there were zero changes in testosterone levels in the Tribulus group. Says a lot. [Source]
In a placebo-controlled study, 27 Division II football players received either a placebo or a ZMA supplement for a total of seven weeks during their scheduled spring practice. At the end of the seven weeks, the players taking the ZMA supplement had a 30 percent increase in testosterone, while the placebo group had a 10 percent decrease. The ZMA group also saw an 11.6 percent increase in strength, compared to only 4.6 percent in the placebo group.
These researchers took saliva samples from recreational women athletes before and after playing 10 minutes of flag football. The data showed that this short, intense burst of competitive sport triggered the immediate release of testosterone. Interestingly, the subjects' mental state also contributed to the data. Self-rated performance scores were directly related to testosterone levels.