Over our lifetimes, we experience numerous hormonal changes. In males, for example, testosterone peaks in very early years (ages 13 – 20) and decreases continually over the decades. This hormone, not only control sexual drive, but also controls muscle size and strength.

Similarly, in women, estrogen peaks and declines over time. This hormone is also related to bone growth and development. Deficiencies in estrogen may cause many menopausal symptoms.

Human growth hormone from the pituitary gland peaks in the late 20s and early 30s. In fact, although HGH is a “banned” substance in most athletic sports, there is a sub-culture that is investigating and taking HGH supplements as an “antidote” for aging. [NOTE: this is highly speculative and controversial, and not recommended]