Guide to Total Testosterone

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

Total testosterone is a measurement of the overall amount of testosterone in your blood, including both free testosterone (not bound to proteins) and testosterone that is bound to carrier proteins (primarily sex hormone-binding globulin and albumin).

Why It Matters

In men, testosterone is primarily produced in the testicles and drives the development of male sexual characteristics during puberty, including genital growth, deepening voice, and facial/body hair. Throughout adulthood, it maintains muscle mass, bone density, fat distribution, red blood cell production, sperm production, and sex drive. Testosterone also influences mood, energy levels, and cognitive function.

In women, testosterone is produced in smaller amounts by the ovaries and adrenal glands. Even at these lower levels, however, it contributes to muscle and bone strength, energy, sexual desire, and overall well-being.

Measuring total testosterone helps evaluate symptoms potentially related to hormone imbalance, such as reduced sexual function, infertility, fatigue, mood changes, or abnormal development. In men, low testosterone (hypogonadism) becomes more common with age, affecting approximately 40 percent of men over 45 to some degree. In women, high testosterone may indicate conditions like polycystic ovary syndrome (PCOS).

While total testosterone provides a good overall assessment, it has limitations. Since most testosterone is bound to proteins in the blood, particularly sex hormone-binding globulin (SHBG), conditions that alter these binding proteins can affect total testosterone without changing the amount of bioavailable hormone. In some cases, free testosterone or bioavailable testosterone measurements may provide additional insights.

Associated Symptoms

Testosterone levels themselves are laboratory findings rather than medical conditions. However, abnormal levels may be associated with various health conditions, each with its own symptoms.

Common symptoms that may indicate conditions associated with low testosterone in men:

• Reduced sex drive: Decreased interest in sexual activity can be due to testosterone's central role in regulating libido
• Erectile dysfunction: Difficulty achieving or maintaining erections, may be related to testosterone's effect on vascular and neurological aspects of erectile function
• Fatigue: Persistent low energy despite adequate rest, may reflect testosterone's role in metabolism and energy regulation
• Decreased muscle mass: Loss of lean tissue despite no change in physical activity, may be due to testosterone's anabolic effects on muscle
• Increased body fat: Particularly around the abdomen, can result from altered fat metabolism with reduced testosterone
• Mood changes: Irritability, depression, or lack of focus, may be related to testosterone's effects on brain function
• Reduced body and facial hair: May be seen in more severe or prolonged testosterone deficiency
• Decreased bone density and increased fracture risk: Can result from long-term testosterone deficiency

Common symptoms that may indicate conditions associated with high testosterone in men:

• Acne or oily skin: Can result from excessive stimulation of oil glands by androgens
• Aggressive behavior: May be related to testosterone's effects on specific brain regions
• Male pattern baldness: Accelerated hair loss can occur in genetically predisposed individuals
• Excessive sex drive and aggressive behavior: Could suggest anabolic steroid use or rarely, testosterone-producing tumors

Common symptoms that may indicate conditions associated with low testosterone in women:

• Decreased sex drive: Reduced interest in sexual activity, as testosterone contributes to female libido
• Fatigue: Persistent low energy despite adequate rest
• Decreased bone density: Over time, may lead to increased fracture risk
• Loss of muscle mass and strength: Associated with aging, menopause, or adrenal insufficiency)
• Thinning hair: May occur with overall hormonal imbalances

Common symptoms that may indicate conditions associated with high testosterone in women:

• Irregular or absent menstrual periods: Disruption of normal ovulatory cycles may be caused by excess androgens
• Excessive facial and body hair growth: Stimulation of hair follicles in androgen-sensitive areas
• Acne: Increased oil production in the skin may be due to androgen effects
• Male-pattern hair loss: Thinning at the crown or temples can be due to testosterone's effects on hair follicles

It's important to understand that many factors can cause these symptoms, and testosterone levels are just one piece of diagnostic information. The presence of symptoms alongside abnormal testosterone provides context for further investigation, but additional testing is typically needed to determine the underlying cause.

Clinical Ranges

Female:

• ≥18 Years: 2-45 ng/dL

Male:

• ≥18 Years: 250-1100 ng/dL

Lifestyle Factors That Can Impact It

Activities that may increase testosterone include the following:

• Adequate sleep (7--9 hours nightly)
• Strength training
• Maintaining healthy body weight (for overweight men)
• Zinc-rich foods (oysters, meat, legumes, nuts)
• Vitamin D (from sunlight exposure and diet)

Activities that may decrease testosterone include the following:

• Chronic, excessive alcohol consumption
• Chronic stress and high cortisol levels
• Severe caloric restriction or crash dieting

Other Factors That Can Impact It

Medical Conditions

• Primary hypogonadism: Decreases testosterone through direct testicular or ovarian damage, affecting hormone production capacity
• Secondary hypogonadism: Reduces testosterone through pituitary or hypothalamic dysfunction that impairs signals stimulating testosterone production
• Type 2 diabetes: Decreases testosterone in men through insulin resistance and inflammatory mechanisms affecting testicular function; elevates testosterone in women via production in the ovaries
• Bilateral oophorectomy: Surgical removal of both ovaries dramatically decreases testosterone
• Bilateral orchiectomy: Surgical removal of both testicles dramatically decreases testosterone
• Chronic liver disease: Reduces testosterone through impaired metabolism of sex hormones and increased sex hormone-binding globulin production
• Chronic kidney disease: Lowers testosterone through disrupted hormonal signaling and increased inflammation
• PCOS: Increases testosterone in women through abnormal ovarian function and insulin resistance
• Klinefelter syndrome (XXY genetic pattern): Reduces testosterone through impaired testicular development and function
• Pituitary disorders and tumors: Decrease testosterone when they affect gonadotropin production, which stimulates testosterone synthesis
• Adrenal insufficiency (Addison's disease), primarily in women, through damage to the adrenal glands
• Premature menopause: Reduces free testosterone due to earlier-than-expected decline in ovarian function, which significantly decreases androgen production
• Primary ovarian insufficiency: Reduces free testosterone due to impaired ovarian function and diminished androgen production from ovarian tissue

Medications

• Opioid pain medications: Decrease testosterone through suppression of the hypothalamic-pituitary-gonadal axis
• Glucocorticoids (such as prednisone): Reduce testosterone through suppression of pituitary hormone production
• Androgen deprivation therapy: Dramatically lowers testosterone by design and is used in prostate cancer treatment
• Medications: Exogenous androgens---like anabolic steroids---can suppress natural testosterone production
• Supplements like dehydroepiandrosterone (DHEA) or pregnenolone may modestly increase testosterone levels in some people by acting as precursors in the steroid hormone pathway, but the effect is often small and inconsistent, especially in men with normal testicular function
• Chemotherapy and radiation: Reduce testosterone through direct damage to testicular tissue and disruption of the hormonal signaling pathway
• Hormonal contraceptives: Decrease testosterone production

Testing Accuracy and Stability

Total testosterone testing can be influenced by several factors, requiring careful preparation and interpretation.

Factors That Can Affect the Accuracy of Your Test:

• Time of day significantly impacts results, with the highest levels typically seen in the morning and the lowest in the evening, especially in younger men.
• Testing method matters---mass spectrometry methods are considered more accurate than immunoassays, especially for lower ranges common in women and children.
• Recent sexual activity might cause a slight, short-lived increase in total testosterone in some men, driven by arousal or ejaculation, but the effect is typically minor and fades within hours, not days.
• Acute illness can temporarily decrease levels, making testing during illness potentially misleading.
• Strenuous exercise within 24 hours of testing can either increase levels (short, intense exercise) or decrease levels (prolonged endurance exercise).

How It Relates to Other Markers

Other tests can provide insights about health status when they're viewed alongside total testosterone results. These tests may include:

• SHBG: This is the primary protein that binds testosterone, rendering it inactive. High SHBG decreases available testosterone while low SHBG increases it.
• Free testosterone: This marker measures unbound, biologically active testosterone. It's particularly important when SHBG levels are abnormal, as they can mask normal or low free testosterone despite normal total levels.
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH): These tests help distinguish between primary (testicular/ovarian) and secondary (pituitary/hypothalamic) causes of testosterone abnormalities.
• Estradiol: This female sex hormone is a form of estrogen. The balance between testosterone and estrogen affects many bodily functions. It's particularly important in men with symptoms of low testosterone.
• Prolactin: This hormone affects many bodily functions in both women and men. Elevated prolactin can suppress testosterone production and cause similar symptoms.
• Hemoglobin/hematocrit: Hemoglobin measures the amount of oxygen-carrying protein in red blood cells. Hematocrit measures the percentage of red blood cells in your blood. Testosterone increases red blood cell production, so it's important to monitor these markers during testosterone therapy.
• Prostate-specific antigen (PSA): This test can help detect enlargement or inflammation of the prostate. In some men, testosterone may stimulate prostate growth, so it's important to also monitor PSA during testosterone therapy.

What Results May Mean in the Context of Other Markers

• Low total testosterone with high LH/FSH: May suggests primary hypogonadism---the testes or ovaries aren't producing adequate testosterone despite stimulation (testicular/ovarian failure).
• Low total testosterone with low/normal LH/FSH: May indicate secondary hypogonadism---the pituitary isn't sending adequate signals to stimulate testosterone production.
• Low total testosterone with high SHBG: May result in very low free testosterone despite only moderately low total levels---can explain why symptoms may be worse than total levels suggest.
• Normal total testosterone with low SHBG: May result in high free testosterone despite normal total levels---common in insulin resistance and obesity.
• High total testosterone in women with high LH/FSH: May suggest PCOS or other ovarian disorders.
• High total testosterone with low LH/FSH: May indicate a testosterone-producing tumor or adrenal source of excess androgens.

Follow-up Considerations

If your total testosterone levels are abnormal, your provider may make some of the following recommendations. You should always speak to your doctor if you have medical questions or before making medical decisions.

When Re-Testing May Be Appropriate

• Initial abnormal result: Often repeated to confirm findings
• During testosterone replacement therapy: 3--6 months after starting, then annually
• When monitoring known conditions: Every 6--12 months
• After significant weight loss: 3--6 months to reassess levels
• After addressing potential reversible causes: 2--3 months
• With changing symptoms: As needed to reassess status

Additional Testing or Monitoring Your Doctor May Consider

• Comprehensive metabolic panel (liver and kidney function)
• Morning cortisol levels
• Thyroid function tests
• Bone density scan if chronically low testosterone
• Pituitary imaging if secondary hypogonadism suspected
• Genetic testing in certain cases

When Additional Care May Be Warranted

• Severely abnormal levels (>30 percent outside reference range)
• Infertility concerns
• Delayed or precocious puberty in adolescents
• Rapidly developing symptoms of hormone imbalance
• Testosterone abnormalities with serious comorbidities (cardiovascular disease, diabetes)
• Suspicion of testosterone-producing tumor
• Bone density concerns with chronic low testosterone
• Need for fertility preservation before testosterone therapy
• Women with significant hirsutism, menstrual abnormalities, and elevated testosterone

Bibliography