So, how does one ensure that testosterone levels remain in balance? Some doctors suggest that monitoring testosterone levels every five years, starting at age 35, is a reasonable strategy to follow. If the testosterone level falls too low or if the individual has the signs and symptoms of low testosterone levels described above, testosterone therapy can be considered. However, once testosterone therapy is initiated, testosterone levels should be closely monitored to make sure that the testosterone level does not become too high, as this may cause stress on the individual, and high testosterone levels may result in some of the negative problems (described previously) seen.
Follicle Stimulating Hormone (FSH) - In women FSH is often used as a gauge of ovarian reserve. In general, under 6 is excellent, 6-9 is good, 9-10 fair, 10-13 diminished reserve, 13+ very hard to stimulate. In PCOS testing, the LH:FSH ratio may be used in the diagnosis. The ratio is usually close to 1:1, but if the LH is higher, it is one possible indication of PCOS. Basic hormone testing for males often only includes testosterone and FSH. However, in cases such as Klinefelters Syndrome doctors will usually look at both FSH and LH levels. In males FSH stimulates the Sertoli cells in the testes to produce androgen-binding proteins, testosterone, and a protein called inhibin. Inhibin, in turn, travels in the blood back to the pituitary gland whre it creates a "negative feedback loop" that decreases the output of FSH. Since FSH stimulates testosterone production, and testosterone can be converted to DHT and estradiol, an increase of any or all three can also create a "feedback loop" that decreases FSH secretion.