Testosterone is the principle sex hormone responsible for the development of
reproductive function in male vertebrates. Testosterone is one of the hormones
referred to as androgens, which are also known of as anabolic steroids.

In male, testosterone is required for the development of male sex organs such as
increased penis and testes size. The hormone also promotes the development of
sexual male characteristics during puberty such as voice deepening and the growth
of armpit, chest and pubic hair. Testosterone plays an important role in maintaining
sex drive, sperm production, muscle strength and bone mass.
A healthy level of testosterone is also protective against bone disorders such as
osteoporosis.
Testosterone is also important for maintaining bone strength and lean muscle mass
in women, as well as contributing to overall well-being and energy levels.

 Causes of low-T include chronic medical conditions such as diabetes,
infections, obesity, or other hormonal conditions.
 Symptoms of low-T include:
 Change in sleep patterns
 Reduced sex drive (low libido)
 Sexual dysfunction
 Infertility

They concluded that having a higher testosterone level appears to increase the risk
of developing metabolic diseases such as type 2 diabetes in women but proves
beneficial in reducing that same disease risk in men.1
The effect on women is not really a surprise, as PCOS is a hormonal disorder that
commonly occurs among women of child-bearing age. Those affected may have
prolonged or infrequent menstrual periods,

Some studies have reported that testosterone therapy might increase the risk of a
heart attack in men age 65 and older, as well as in younger men who have a history
of heart disease. Other studies have found a higher frequency of death and heart
problems in men who had coronary artery disease and received testosterone
therapy.