by Birgir Hernandez
What Is Testosterone Testing and Why Is It Done?
Testosterone tests are laboratory tests that help determine the concentration of testosterone present in the blood. Although testosterone is mostly associated with male individuals, testosterone is secreted by both males and females; an imbalance in testosterone production has implications for health. Testosterone tests may be recommended in case of symptoms associated with an imbalance in the concentration of testosterone, infertility, sexual health, puberty problems, certain hormone disorders, and hormone replacement therapy. However, testosterone testing is not just about one figure from the lab report. There are various aspects that play a role in how the result is understood: when the test is taken, what type of testosterone was checked (total or free), what symptoms you have, your age, sex, medications, and other health considerations. What Is Testosterone? Testosterone is a type of androgenic hormone that has many different functions in the body. For example, in men, it is mainly secreted by the testes, while in women, small amounts are secreted by the ovaries and adrenal glands. Testosterone contributes to: Sex drive and sexual function Sperm production Muscle development and maintenance Bone health Body and facial hair growth Red blood cell production Puberty and reproductive development Energy and overall physiological function Testosterone levels naturally change throughout life and also fluctuate during the day. This is one reason the timing of a testosterone test matters. What Is a Testosterone Test? The testosterone test is mostly a blood test that measures levels of testosterone in your blood. There are different types of methods used to evaluate testosterone levels; however, there are two names that you will hear the most: Total Testosterone and Free Testosterone. Total Testosterone Total testosterone measures testosterone that is both: Bound to proteins in the blood Unbound or free It is commonly used as the initial laboratory measurement when evaluating suspected testosterone deficiency. Free Testosterone Free testosterone refers to testosterone that is not bound to proteins. Only a small portion of testosterone circulates in this form. In certain situations, measuring or calculating free testosterone can provide additional information, particularly when total testosterone is near the lower end of the reference range or when levels of sex hormone-binding globulin (SHBG) may be altered. The Endocrine Society recommends using accurate testing methods and considering free testosterone when clinically appropriate rather than relying on a single measurement in every situation. Why Is Testosterone Testing Done? The main reason for testosterone testing is to investigate symptoms or medical concerns that could be associated with abnormal testosterone levels. However, a testosterone test by itself does not diagnose a condition. Healthcare providers generally interpret the laboratory result alongside symptoms, medical history, physical findings, and sometimes additional testing. Testosterone Testing for Men A healthcare provider may consider testosterone testing when a man has symptoms that could indicate testosterone deficiency. Possible symptoms include: Reduced sex drive Erectile dysfunction Infertility Reduced muscle mass Decreased body or facial hair Enlarged breast tissue Low energy Changes in mood or concentration Reduced bone density or unexplained fractures Not every person with one of these symptoms has low testosterone. Many of these symptoms can have other causes, which is why laboratory testing needs to be interpreted in context. Clinical guidelines recommend diagnosing male hypogonadism only when compatible symptoms or signs occur together with consistently low testosterone measurements. Testosterone Testing for Women Testosterone testing can also be useful for women when there are signs of androgen excess or other hormonal concerns. A healthcare provider may consider testing when symptoms include: Excess facial or body hair Acne Irregular or absent menstrual periods Unexplained scalp hair loss Voice changes Fertility problems Other signs of androgen excess The interpretation of testosterone results in women differs from interpretation in men because expected levels are different. MedlinePlus and Cleveland Clinic both note that testosterone testing may be used to investigate abnormal testosterone production in women as well as men. Testosterone Testing for Children and Teenagers Testosterone testing may sometimes be used when puberty occurs earlier or later than expected. Depending on the child's symptoms and development, testing may help healthcare providers investigate possible hormonal or developmental conditions. When Should Testosterone Be Tested? In the case of men suspected of having testosterone deficiency, it is advisable to take samples to measure testosterone levels in the morning, since testosterone levels at this time are usually high. According to The Endocrine Society, morning samples are preferred, together with repeat testing of low values to diagnose deficiency as opposed to a single sample. Similarly, the newer 2026 European guidelines also recommend morning, fasting samples and standardized laboratory testing for male hypogonadism evaluation. This is important since the level of testosterone fluctuates with time, among other things. Do You Need to Fast Before a Testosterone Test? Fasting might be required depending on the specific test and laboratory guidelines. While some laboratory procedures require you to fast before providing a blood sample, others might not. Your healthcare provider or laboratory will give you detailed guidelines on how to prepare for the test. Do not stop taking prescription drugs or supplements because you are undergoing testosterone testing. Instead, tell your doctor about everything that you take and follow the instructions from the laboratory. Additionally, certain lab tests can be affected by specific dietary supplements, such as high doses of biotin. Major laboratories, including Labcorp, note that high-dose biotin can interfere with certain testosterone assays. Total Testosterone vs. Free Testosterone: What's the Difference? One of the most important distinctions to understand is the difference between total and free testosterone. Test What It Measures When It May Be Useful Total testosterone Bound + unbound testosterone Common starting test Free testosterone Unbound testosterone May provide additional information in selected cases Bioavailable testosterone Free testosterone plus testosterone loosely bound to albumin Used less commonly Most testosterone in the bloodstream is bound to proteins such as SHBG and albumin. Because SHBG affects how much testosterone is available in the free form, two people with similar total testosterone levels can sometimes have different free testosterone levels. This is why healthcare providers may consider SHBG and free testosterone when the total testosterone result is borderline or when a person's health condition may alter SHBG levels. Why Does the Timing of Testosterone Testing Matter? Testosterone follows a daily rhythm. Levels are generally higher in the morning and lower later in the day. This daily variation is one reason a random afternoon testosterone measurement may not provide the same information as a properly timed morning test. For suspected testosterone deficiency, clinical guidance commonly recommends morning testing, with repeat testing used to confirm a low result. If you are getting tested, follow the timing instructions provided by your healthcare professional or laboratory. What Can Affect Testosterone Test Results? Testosterone levels can vary because of factors beyond a person's underlying hormone production. Potential influences include: Time of day Age Body weight and metabolic health Acute illness Certain medications Hormone therapy Changes in SHBG Food intake and fasting status Laboratory testing method Normal day-to-day biological variation This is why a testosterone result should not be interpreted in isolation. A result outside a laboratory's reference range does not automatically mean you have a disease. Your healthcare provider may recommend repeat testing or additional hormone tests before concluding. For people considering broader hormone testing, the type and scope of testing can depend on symptoms, medical history, and the clinical question being investigated. What Does a Low Testosterone Result Mean? A low testosterone result can have several possible explanations. In men, persistently low testosterone combined with compatible symptoms may be associated with hypogonadism. The underlying cause can involve the testicles, hypothalamus, pituitary gland, medications, chronic health conditions, or other factors. Importantly, one low testosterone result does not necessarily mean you have testosterone deficiency. The Endocrine Society recommends confirming consistently low testosterone with repeat morning testing before making a diagnosis. Additional testing may be needed to determine why testosterone is low. Depending on the situation, a healthcare provider may consider tests such as: LH FSH SHBG Free testosterone Prolactin Thyroid testing Other metabolic or reproductive health tests The appropriate tests depend on the individual's symptoms and medical history. For broader preventive testing, a lab testing collection may include different types of laboratory assessments depending on the individual's needs. What Does a High Testosterone Result Mean? High testosterone can have different meanings depending on the person's age, sex, symptoms, medications, and whether hormone therapy is being used. In women, elevated testosterone may be investigated when symptoms suggest androgen excess. In men, an unexpectedly high result may require further evaluation depending on the circumstances. A high result should not automatically be interpreted as evidence of better health or greater vitality. The goal of testosterone testing is to understand whether hormone levels are appropriate for the individual and clinical situation, not simply to obtain the highest possible number. Is Testosterone Testing Recommended for Everyone? Not necessarily. Routine screening of every asymptomatic adult for low testosterone is not generally recommended by major clinical guidance. Instead, testing is typically considered when symptoms, physical findings, medical history, fertility concerns, hormone therapy, or another clinical reason suggests that testosterone evaluation may be appropriate. The European Academy of Andrology specifically recommends against universal screening for hypogonadism in middle-aged or older men using random testosterone measurements. This distinction is important because symptoms such as fatigue, low motivation, weight changes, and poor sleep can have many possible causes. If you are experiencing multiple unexplained symptoms, warning signs that may indicate a need for lab testing can be useful to discuss with your healthcare provider. Can You Take a Testosterone Test at Home? Some testing laboratories also provide testosterone kits that are tested at home. The specific kit determines whether a finger-prick blood sample, saliva, or urine sample is required before being sent to the laboratory for analysis. But an at-home test result cannot stand alone. If the results are abnormal or if there are any other symptoms present along with the at-home test results, you should discuss the results directly with a healthcare professional. For additional information about testing options that can be performed from home, see this guide to at-home diagnostic tests. Testosterone Testing vs. Comprehensive Hormone Testing A standalone testosterone test answers a relatively narrow question: how much testosterone is present in the sample? A more general hormone test might involve a number of hormones and, depending on the testing method, their metabolites or patterns. For example, Be So Well's DUTCH Hormone Testing options evaluate multiple hormones and hormone metabolites, including testosterone, estrogen, progesterone, cortisol, and DHEA. This kind of testing may be appropriate if the problem under consideration involves the pattern of the hormones. It all depends on your symptoms, needs, medical history, and the questions you ask. A more detailed overview of comprehensive hormone testing is available in the DUTCH Plus Hormone Test Kit guide. What Happens After a Testosterone Test? Once your results are available, your healthcare provider will generally look at more than the testosterone number. They may consider: Your symptoms Your age and sex The time the sample was collected The laboratory's reference range Total and/or free testosterone SHBG and other relevant markers Medications and supplements Existing health conditions Whether repeat testing is necessary If testosterone is low, repeat testing may be recommended before making a diagnosis. If the result is abnormal, additional laboratory testing may help identify the underlying reason. A broader overview of routine laboratory screening is available in the guide to essential blood tests. Testosterone Testing: A Simple Symptom-to-Test Guide Concern Testosterone Testing May Be Considered? Why Low sex drive in a man Yes May help evaluate possible testosterone deficiency Erectile dysfunction Sometimes Testosterone may be one part of the evaluation Male infertility Yes Hormonal evaluation may be appropriate Unexplained loss of muscle mass Sometimes May warrant broader evaluation Excess facial hair in a woman Yes May help evaluate androgen excess Irregular periods Sometimes Testosterone may be part of a broader hormone evaluation Acne with other androgen-related symptoms Sometimes May warrant evaluation for elevated androgens Early or delayed puberty Yes May help investigate hormonal development Fatigue alone Not necessarily Fatigue has many possible causes This table is a starting point, not a diagnostic tool. Your healthcare provider can determine which tests make sense based on your symptoms. Key Takeaways About Testosterone Testing Testosterone testing can provide useful information about hormone levels, but the result needs to be interpreted in context. The most important points to remember are: A testosterone test usually measures testosterone in a blood sample. Total testosterone measures both bound and unbound testosterone. Free testosterone measures the unbound portion. Testosterone levels naturally fluctuate during the day. Morning testing is generally preferred when evaluating suspected testosterone deficiency. A single low result may need to be repeated. Symptoms and laboratory results should be considered together. SHBG can affect the relationship between total and free testosterone. Men and women may be tested for different clinical reasons. At-home testing is available, but results should not be used for self-diagnosis. Broader hormone testing may be appropriate when the concern extends beyond testosterone alone. Frequently Asked Questions About Testosterone Testing What is a testosterone test used for? A testosterone test measures testosterone levels in the blood. It may be used to investigate symptoms of low testosterone in men, signs of androgen excess in women, fertility concerns, abnormal puberty, or to monitor certain hormone therapies. What is the best time to test testosterone? When evaluating suspected testosterone deficiency in men, testing is generally performed in the morning because testosterone levels are typically higher earlier in the day. Clinical guidance also recommends confirming a low result with repeat testing. Is total or free testosterone better? Neither test is universally "better." Total testosterone is commonly used as the initial measurement. Free testosterone may provide additional information in selected situations, particularly when total testosterone is borderline, or SHBG levels may be altered. Can women get testosterone testing? Yes. Women produce testosterone and may be tested when symptoms suggest elevated androgen levels, such as excess facial or body hair, acne, irregular periods, hair loss, or certain fertility concerns. Does one low testosterone test mean I have low testosterone? Not necessarily. Testosterone levels vary, and clinical guidelines recommend confirming consistently low levels with appropriately timed repeat testing when diagnosing testosterone deficiency in men. Symptoms and other clinical information are also important. Can I test testosterone at home? Some companies offer at-home testosterone testing kits. However, test accuracy and collection methods can vary, and an abnormal result should be discussed with a healthcare professional rather than used for self-diagnosis. Final Thoughts Testosterone testing is a useful way to measure testosterone levels when there is a specific health reason to investigate hormone status. The most useful result isn't simply the highest or lowest number. Proper timing, the type of testosterone measured, laboratory reference ranges, symptoms, SHBG, medications, and other health factors can all influence interpretation. If you are experiencing symptoms that may be related to hormone changes, testing can be one part of a broader evaluation. For people who need a wider look at hormone patterns, Be So Well also offers DUTCH hormone testing, which evaluates multiple hormones and metabolites rather than testosterone alone.
