When most people hear "testosterone," they think of bulging muscles and masculinity, but this powerful hormone plays a much more nuanced and essential role in human health—for both men and women—than just in the development of secondary sex characteristics.
What may be surprising is that, for both sexes, testosterone influences numerous bodily functions and is required in everyone’s body to be happy and healthy. In this post, you’ll learn all about testosterone, including how it affects everyone's health and what happens when levels fall outside the optimal range.
What Is Testosterone, Really?
At its core, testosterone is both a sex hormone and a steroid hormone that belongs to a class called androgens—hormones that promote the development of male characteristics. But labeling it "the male hormone" doesn't do justice to its complexity.
Chemically speaking, testosterone is derived from cholesterol through a series of chemical reactions inside your body.
While primarily produced in the testes in men (about 95% of male testosterone comes from here), it's also made in smaller amounts by the adrenal glands. Women produce testosterone too, though in much smaller quantities (about 1/10th of men), primarily in the ovaries and adrenal glands.
Testosterone doesn't work alone—it's one of many hormones that work together to keep your body functioning properly. In both sexes, it interacts with other hormones like estrogen (yes, men have some estrogen too), cortisol, insulin, and growth hormone to maintain overall physiological balance.
Testosterone's Role in Men's Health
In men, testosterone guides the development of their reproductive system before birth. During puberty, it triggers the characteristic changes that transform boys into men: deepening voice, facial and body hair growth, genital development, and the adolescent growth spurt.
But testosterone's influence extends far beyond these visible changes. First, testosterone stimulates protein synthesis, helping to build and maintain muscle mass. It also increases bone density and strength in men, protecting against osteoporosis later in life.
Beyond driving libido, testosterone is essential for erectile function, sperm production, and overall reproductive health.
Testosterone also helps control body fat distribution, particularly preventing excess abdominal fat (visceral fat). It also influences insulin sensitivity and glucose metabolism.
On top of that, testosterone affects brain function, influencing spatial abilities, your ability to concentrate, memory, and even mood regulation. It also stimulates your bone marrow to produce red blood cells, which is why men typically have higher hemoglobin levels than women.
Finally, optimal testosterone levels support heart health by promoting healthy cholesterol profiles and vascular function.
The Overlooked Role of Testosterone in Women
While women produce about 1/10th the amount of testosterone that men do, this smaller quantity plays a vital role in their health.
Importantly, testosterone drives sexual desire and arousal in women, contributing to sexual satisfaction and function. When levels fall, desire falls as well.
Just as in men, testosterone helps women maintain muscle mass and bone density. Optimal levels contribute to vitality, motivation, and emotional well-being.
Finally, testosterone contributes to ovarian function and is a precursor for estrogen production—your body actually converts some testosterone into estrogen.
When Testosterone Runs Low in Men
The physical changes associated with low testosterone can be serious and debilitating, including:
● Decreased muscle mass and strength despite maintaining exercise habits
● Increased body fat particularly around the midsection
● Reduced bone density that may progress to osteoporosis
● Sevelopment of gynecomastia (enlarged breast tissue)
● Accelerated hair loss in genetically susceptible individuals
Sexual dysfunction is a common and often distressing symptom, manifesting as reduced libido that may severely impact intimate relationships. Men may also have erectile difficulties that don't respond to conventional treatments or fertility problems due to decreased sperm production.
Low Testosterone in Women
Women with testosterone deficiency often experience symptoms that overlap with those seen in men, though they may manifest differently.
The sexual impact of low testosterone in women includes dramatically diminished libido that affects relationship satisfaction, reduced sexual pleasure, difficulty achieving orgasm, and vaginal dryness that may occur independently of estrogen status.
Physical changes can be subtle but significant, with many women noticing decreased muscle tone despite consistent exercise, increased central body fat that resists diet and exercise, and accelerated bone loss that increases fracture risk beyond what would be expected from estrogen decline alone.
When Testosterone Levels Are Too High
While low testosterone is usually the focus for men, excessive levels can also cause health problems.
In men, abnormally high testosterone can lead to serious consequences. These men frequently experience significant psychological changes including unpredictable mood swings, heightened irritability that disrupts relationships, and potentially increased aggression that may manifest in uncharacteristic confrontational behavior.
Cardiovascular issues become a major concern with sustained high testosterone, including increased risk of heart attack and stroke due to blood vessel changes, chronically elevated blood pressure that damages organs over time, and unhealthy cholesterol profiles marked by decreased HDL (good cholesterol) and increased LDL (bad cholesterol).
In women, elevated testosterone, often seen in conditions like polycystic ovary syndrome (PCOS), comes with its own set of problems.
Menstrual irregularities typically appear early, including missed or infrequent periods that may be mistaken for other gynecological conditions, unpredictable or abnormal uterine bleeding that causes social and practical difficulties, and in some cases, early onset menopause.
Fertility becomes a significant challenge due to disrupted ovulation patterns caused by hormonal imbalances, making conception difficult without medical help.
Physical changes can be particularly distressing—some women develop hirsutism (excessive facial and body hair) that affects self-image, male-pattern baldness that may not respond to conventional hair loss treatments, and persistent acne that tends to worsen around the jawline and lower face.
If You’re Experiencing the Symptoms of Low T, We Can Help
Whether you're a man or a woman, having clinically low testosterone levels can reduce your quality of life, especially your sex life.
If you’re experiencing the symptoms of low T, your next step is to get your hormone levels tested.
Learn more about TRT for men here or how testosterone can help some women—especially those with low libido—here.
You can also schedule an appointment with a specialist today to discuss getting your levels tested.