Testosterone is a hormone, one of a group of chemicals produced by your body to regulate the function of body organs such as the brain, bones, muscles, heart and blood vessels. While it's commonly known as the "male hormone" that regulates sexual function in men, testosterone plays an important role in women as well. Your testosterone levels determine whether you develop gender-specific characteristics like body hair and genitalia and influence sexual functioning.
Testosterone Production
The pituitary gland in both men and women controls testosterone levels by releasing a hormone known as luteinizing hormone, or LH. When testosterone levels are low, the pituitary secretes more LH and triggers the adrenal glands to produce testosterone. In addition, men release a significant amount of testosterone from their testicles and women secrete a lower amount from their ovaries.
Measuring Testosterone Levels
Your doctor may send you to a medical laboratory for a simple blood test that measures testosterone levels. According to Lab Tests Online, you don't need to do anything special to prepare for this test.
Normal Range
Testosterone levels are lowest during childhood and start to rise at the beginning of puberty. According to the Mayo Clinic, testosterone levels are highest during the teen and early adult years, then decrease about 1 percent a year after age 30. The University of Michigan Health System lists normal lab values showing that a female infant should have less than 10 nanograms/deciliter, or ng/dL, in her blood.
Between seven and nine years of age, the normal level ranges from one to 12 ng/dL and from 10 to 13 years of age, a girl should have a testosterone level of two to 33 ng/dL. Teens between the ages of 14 and 17 typically have eight to 53 ng/dL. Adult women run between 10 and 70 ng/dL before menopause, dropping to seven to 40 ng/dL after menopause.
Effects
Testosterone levels are significantly lower in females than in same-age males. Women who produce too much testosterone may develop male features such as facial and body hair, male pattern baldness and a deeper voice. They may also experience irregular or absent menstrual cycles and infertility, according to Lab Tests Online.
Expert Insight
There's been a good deal of public interest in testosterone therapy to reverse the drop in testosterone levels in post-menopausal women and improve sexual functioning. While is does a good job of improving sex drive and overcoming sexual dysfunction, Mayo Clinic says, "The long-term safety of testosterone therapy for women is unknown."
