Create Account

One Health helps you track and understand your health simply.

Create Account

One Health helps you track and understand your health simply.

Testosterone Total

Endocrine & Reproductive

Testosterone, totalTotal TTotal TestosteroneTT

Review status

Currently under review

Pending specialist review and validation.

What it shows

This test measures the total amount of testosterone in your blood. Total testosterone includes hormone that is bound to proteins, mainly sex hormone binding globulin and albumin, plus a small unbound portion. It reflects overall testosterone production from the testes in most males and from the ovaries and adrenal glands in females.

Your level can vary during the day, usually being highest in the morning, and can be influenced by age, health conditions, and medications. The test is typically performed on a blood sample from a vein and can be used alone or with related tests, such as free testosterone or sex hormone binding globulin, depending on your clinical situation.

Why it matters

Testosterone plays key roles in puberty, sexual function, mood, muscle and bone maintenance, and red blood cell production. Your clinician may order this test to evaluate symptoms that could be related to too little or too much testosterone, to investigate menstrual or fertility concerns, to assess conditions like polycystic ovary syndrome, or to monitor therapy that can change testosterone levels.

In adults, it helps evaluate possible hypogonadism, pituitary disorders, and certain adrenal or ovarian conditions. It is also used to monitor treatment with testosterone or medicines that suppress androgens, and to help assess athletic or supplement use that may affect hormone balance. Results are interpreted in the context of your age, sex, and health history.

Understanding your results

Your result is interpreted against reference intervals specific to age and sex, the timing of collection, and the method used by the laboratory. A single result outside the expected interval does not always mean there is a problem. If results do not fit your symptoms, your clinician may repeat testing in the early morning, check related hormones, or order a free testosterone or sex hormone binding globulin test for a fuller picture.

Lower values can be associated with conditions that affect the testes or pituitary, chronic illness, higher body fat, or certain medications. Higher values can reflect ovarian or adrenal disorders, testicular conditions, or use of testosterone or anabolic agents. Follow-up may include additional labs, imaging, or changes in medications. Discuss any supplements or therapies you take, since these can change results and the best next steps.

Reference ranges

-- nmol/L
Female
0 days – 18 years
-- nmol/L
Male
0 days – 18 years
0.352.7 nmol/L
Female
18 years – 150 years
2.821.6 nmol/L
Male
18 years – 150 years

Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.

Factors that could impact Testosterone Total

  • Time of day

    Testosterone follows a daily rhythm, often peaking in the morning. Early morning collection provides the most consistent assessment, especially in adult males.

  • Medications and supplements

    Testosterone therapy, anabolic steroids, antiandrogens, glucocorticoids, opioids, and some anticonvulsants can raise or lower results. High-dose biotin may interfere with some assays; tell your clinician what you take.

  • Binding proteins and health conditions

    Changes in sex hormone binding globulin with obesity, thyroid or liver disease, aging, pregnancy, or estrogen therapy can shift total testosterone without reflecting true biologic activity.

  • Illness, stress, and exercise

    Acute illness, poor sleep, high stress, and intense exercise around the time of testing can transiently alter hormone levels. Stable health conditions improve result reliability.

  • Menstrual cycle and contraception

    In menstruating individuals, timing within the cycle and use of oral contraceptives or other estrogen-containing therapies can change measured total testosterone.

  • Sample handling and assay differences

    Improper sample handling or differences between immunoassay and mass spectrometry methods can affect accuracy. Repeat testing or method confirmation may be recommended.

  • Age and puberty

    Levels change with age and during puberty. Pediatric and adolescent interpretation requires age- and sex-specific context provided by your clinician.

  • Gender-affirming care

    Testosterone therapy in transgender men raises levels, while antiandrogen or estrogen therapy in transgender women lowers them. Monitoring plans are tailored to treatment goals.

2026

References

  1. McGill University Health Centre. (2015, June 22). Testosterone Total (Task CD 317350). Laboratory reference ranges.
  2. McGill University Health Centre. (2017, September 29). Testosterone Total (Task CD 317350). Laboratory reference ranges.
  3. Bhasin, S., Brito, J. P., Cunningham, G. R., Hayes, F. J., Hodis, H. N., Matsumoto, A. M., Snyder, P. J., Swerdloff, R. S., & Wu, F. C. (2018). Testosterone therapy in men with hypogonadism: An Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism, 103(5), 1715-1744. External link
  4. Martin, K. A., Chang, R. J., Ehrmann, D. A., Ibáñez, L., Lobo, R. A., Rosenfield, R. L., & Yildiz, B. O. (2018). Evaluation and treatment of hirsutism in premenopausal women: An Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism, 103(4), 1233-1257. External link