What is Testosterone?
Key Takeaways
Testosterone is a steroid hormone that’s important for the function of many different body systems.
Both men’s and women’s bodies produce testosterone, though the levels are much higher in men.
Low testosterone levels can cause a variety of symptoms, including low energy, mood changes, infertility, and decreases in bone density and muscle mass.
High testosterone levels can also cause symptoms, including acne, mood swings, and changes in the body’s appearance.
Both high and low testosterone levels may increase the risk of serious conditions like heart disease.
The most reliable way to check your testosterone levels is with a blood test.
Lifestyle changes may help to bring low or high testosterone levels back into a more normal range. In some cases, medications may be helpful.
Testosterone is part of a group of hormones known as steroid hormones. Other hormones in this group include estrogens, progesterone, and cortisol.
Androgens are steroid hormones that are produced at high levels in men’s bodies, and at lower levels in women’s bodies. Testosterone is the primary androgen – it occurs at the highest levels, and it also has the strongest effect, because it binds more strongly to the androgen receptor than other androgens. The strongest version of testosterone is known as dihydrotestosterone or DHT. There are also other androgens, including androstenedione and dehydroepiandrosterone (DHEA), which are found at lower levels and are not as strong as testosterone.
Testosterone is produced in a few different locations in the body:
The testes or ovaries. In men, the testes produce very high levels of testosterone, accounting for approximately 95% of the total testosterone produced in the man’s body. In women, the ovaries also produce some testosterone, although the levels are much lower than those produced by the testes in men.
The adrenal glands. These are located on top of the kidneys. They produce a variety of hormones, including cortisol (the main stress hormone). In both men and women, the adrenal glands also produce testosterone.
Peripheral tissues. Tissues throughout the body, especially fat tissue and skin, can convert other androgens (including androstenedione and DHEA) into testosterone. This occurs in both men and women.
Functions of Testosterone in the Body
Testosterone plays a variety of important roles in the body. In both men and women, it’s needed for proper functioning of many bodily systems, including:
Muscle mass and strength
Bone density
Red blood cell production
Mood
Cognitive function
Immune system function
Energy levels
Fertility and sexual function
Healthy testosterone levels are important for longevity. Low testosterone can lead to frailty and decreased well-being, and has also been linked to an increased risk of death. At the same time, high testosterone may also increase the risk of dying from a heart attack or stroke. To improve your odds of living a long and healthy life, it’s important to detect and address either low or high testosterone levels.
In men
Testosterone is the primary sex hormone in men. In the embryo, the release of testosterone causes the development of the male reproductive system. This hormone is later responsible for the male characteristics that appear during puberty, like the deepening of the voice, increase in muscle mass, and the growth of facial and body hair.
Testosterone is also crucial for fertility in men, as it’s needed for sperm production. In addition, testosterone is important for a man’s libido, or sex drive.
In women
Although testosterone is sometimes thought of as a “male” hormone, it’s also important for sexual function in women. As in men, testosterone is important for sexual desire in women.
Although hormones like estrogens and progesterone have a larger effect, testosterone is also believed to play a role in fertility in women. There’s evidence that women with low testosterone are less likely to conceive.
Imbalanced Testosterone Levels
Causes of Imbalanced Testosterone
Several different issues can cause a person’s testosterone levels to be too low or too high. Some of these include:
Lifestyle factors. Drinking large amounts of alcohol or drinking frequently can have a significant impact on testosterone, particularly in men. Chronic stress has also been shown to lower testosterone levels, because cortisol (a stress hormone produced by the adrenal glands) reduces the body’s production of testosterone.
Taking hormones. Some men take anabolic steroids (synthetic versions of testosterone) to improve athletic performance and muscle mass, which can lead to dangerously high testosterone levels. Men may also take testosterone replacement therapy to boost low testosterone levels. Without proper medical supervision, this can easily lead to having testosterone levels that are too high. Women may take estrogen in birth control pills or menopausal hormone therapy, which can decrease the production of testosterone in a woman’s body.
Body weight. Fat tissue tends to convert testosterone to estrogen, which can lower testosterone levels in people with obesity.
Aging. Levels of testosterone change as part of the aging process. In men, there is a gradual decline. In women, menopause causes the ovaries to stop producing testosterone along with other hormones.
Glandular problems. Issues with the pituitary gland, adrenal glands, thyroid gland, or the testes or ovaries can all lead to hormonal imbalances that affect testosterone levels, along with the levels of other important hormones.
Chronic medical conditions. Certain conditions, including diabetes and polycystic ovary syndrome (PCOS), can affect testosterone levels. Certain medications can also affect testosterone levels, including many types of chemotherapy, antidepressants, statins (cholesterol-lowering drugs), and pain medications.
Signs and Symptoms of Testosterone Imbalance
People with testosterone levels that are too low or too high may experience a variety of different symptoms. Some of the symptoms of high testosterone levels are the same as those caused by low testosterone, so it can be difficult to tell whether testosterone levels are too high or too low based on symptoms alone.
People with imbalanced testosterone levels may experience changes in:
Energy levels. Imbalanced testosterone levels can lead to low energy and feelings of fatigue.
Muscle and bone mass. Testosterone is crucial for the growth and maintenance of muscle tissue, so imbalanced levels may lead to changes in muscle mass. There’s a strong link between muscle mass and longevity, so testosterone can impact both lifespan and healthspan. Testosterone is also important for maintaining bone tissue, and low levels can lead to decreased bone density, which increases the risk of a fracture.
Mood. Imbalanced testosterone can lead to mood swings, increased aggression, anxiety, or depression.
Body appearance. There may be changes in hair growth on the body, face, and head. High testosterone can also lead to oily and acne-prone skin. Men with low testosterone may experience gynecomastia, or development of female-type breast tissue. Women with high testosterone may experience changes in the sound of the voice.
Sexual function and fertility. Imbalanced testosterone levels are a common cause of infertility in both men and women, and can also cause reduced sex drive. Men may also notice trouble getting or keeping an erection, while women may have irregular menstrual cycles.
Cardiovascular disease. Imbalanced testosterone levels cause an increased risk of having a heart attack, stroke, or a blood clot in the legs, and are associated with a shorter lifespan.
Causes
Some of the possible causes of high testosterone include:
Testing for Testosterone Levels
Although certain symptoms can provide a strong indication that a person’s testosterone levels are too low or too high, the only way to be sure about your testosterone levels is to have them tested.
The most reliable method of checking your testosterone levels is through a blood test. Although there is also a saliva test available, it’s been shown to be less accurate than the blood test.
Steroid hormones are fat-soluble molecules, so they don’t easily dissolve in blood, which is primarily made up of water. Because of this, testosterone is transported through the blood on carrier proteins, primarily albumin and sex hormone-binding globulin (SHBG). This has important effects on the results of a blood test for testosterone.
There are a few different specific types of testosterone blood tests:
Total testosterone. This test measures all of the testosterone in the blood, whether it’s bound to carrier proteins or not.
Free testosterone. This measures only testosterone that’s not bound to carrier proteins. This type of testosterone is the most available for the body to use.
Bioavailable testosterone. This measures free testosterone, along with testosterone that’s only loosely bound to albumin, which is easy for the body to access.
It’s important to understand your testosterone levels in context. This may include determining the ratio of testosterone to other hormones (like estrogens and progesterone). Levels of LH and FSH, which are hormones released by the pituitary that control testosterone secretion in the testes or ovaries, may also be tested. A consultation with your doctor will allow you to gain a more in-depth understanding of your test results.
Normal Testosterone Levels
Testosterone levels commonly decrease with age. In men, the decline occurs gradually as they get older, starting around age 30. This is known as andropause. In women, a sharp decline in testosterone levels occurs when they reach menopause. In premenopausal women, testosterone levels are higher around the time of ovulation than at other times during the menstrual cycle.
There is currently no scientific consensus about the exact cutoffs for healthy testosterone levels. The American Urological Association defines low testosterone as a level of total testosterone below 300 ng/mL. However, there is a lot of variability in the results obtained in different laboratories, because small differences in testing technique can have a significant impact on the results. The best advice is to use the reference ranges provided by your lab, in order to determine whether your levels are low or high for your age and sex. Your doctor can help you to understand what your test results mean in context.
Managing Testosterone Levels
If your testosterone levels are imbalanced, then restoring more normal levels could help to improve your health, well-being, and longevity. Some helpful options include:
Lifestyle Changes
Exercise. Physical activity has been shown to increase testosterone levels, especially in men. Resistance training is the most effective type – this could include weightlifting, using resistance bands, or bodyweight exercises. Aerobic exercise, like running, swimming, or cycling, can also increase testosterone.
Maintain a healthy body weight. Because fat tissue converts testosterone into estrogens, people with obesity frequently have low testosterone levels. Bringing your weight into a healthier range can help to address your testosterone levels as well. This may involve lifestyle changes and, in some cases, weight loss medications known as GLP-1 RAs.
Reduce alcohol consumption. High alcohol intake can lower testosterone. If you drink alcohol regularly, then quitting drinking, or significantly reducing the amount that you drink, can help to raise your testosterone.
Eat a healthy diet. For healthy testosterone levels, you need to eat enough protein and healthy fats. You also need to get enough of certain vitamins and minerals, especially vitamin D, zinc, and magnesium. Reducing saturated fat, trans fat, and processed food may help to reduce the impact of high testosterone and bring it into a more normal range.
Manage stress. Chronic stress reduces testosterone levels. It’s important to find ways of controlling your stress levels. Different people do this differently. Some options include meditation, yoga, spending more time in nature, or spending more time with friends and family.
Get enough sleep. Sleep deprivation can reduce testosterone levels. Prioritize getting 7 to 8 hours of high-quality sleep every night.
Medical approaches
Address underlying conditions. For example, in women with PCOS, addressing this condition can help to bring their testosterone levels into a more normal range. For those with hyperthyroidism, treating this condition will also help with testosterone levels.
Testosterone replacement therapy (TRT). For those whose testosterone is very low, or when lifestyle changes are not enough to bring it up into a healthier range, testosterone replacement therapy may be considered. It’s important to be monitored by a physician when taking TRT, because it could lead to high testosterone levels if you take too much.
Androgen receptor blockers. For those with high testosterone, a medication called spironolactone may be helpful. This medication blocks androgen receptors, reducing the effect of high testosterone.
Estrogen. In women with high testosterone, taking estrogen (often along with progesterone) may help to balance it out and reduce the negative effects.
Healthy Testosterone Levels and Well-Being
Testosterone plays a number of important roles in your body. Low or high testosterone levels can have a significant impact on your well-being and longevity. It’s important to maintain balanced testosterone levels in order to live a long and healthy life.
This is why it’s important to interpret your testosterone test results with a qualified physician. They’ll be able to put the results into context. If your testosterone levels are abnormal, they’ll evaluate you and determine what’s most likely causing this, as well as make a plan for how to address the problem and bring your levels into a healthier range.
Monitoring your testosterone levels is one important step towards achieving your greatest possible longevity and well-being. A comprehensive health screening, which includes measuring testosterone levels along with many other biomarkers, will give you a fuller picture of your current health risks and opportunities for optimisation.
NOVI Assessment Max goes beyond the standard diagnostics, offering a deep, data-driven evaluation of over 100 biomarkers to assess early cardiac, metabolic, hormonal, and age-related health risks.
With doctor-led guidance before and after testing, NOVI Assessment Max gives you clear, personalized insights and an actionable health plan. This allows you to have a better understanding of your health so you can take the right steps toward better long-term health.