Total Testosterone
The total amount of the main androgen in the blood, both bound and free.
| Typical reference range (male) | 264–916 ng/dL |
| Typical reference range (female) | 8–48 ng/dL |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Testosterone is produced mainly by the testes in men and by the ovaries and adrenal glands in women, under the control of LH from the pituitary. Most circulating testosterone is bound to SHBG or albumin; only 1-3% is free.
Why it matters
In men, testosterone supports libido, erectile function, muscle and bone mass, red cell production and mood; low levels define hypogonadism when accompanied by symptoms. In women, elevated testosterone is a key feature of PCOS.
What a high result can mean
In men, high values usually reflect testosterone or anabolic steroid use, or high SHBG. In women, elevated testosterone suggests PCOS, congenital adrenal hyperplasia or, rarely, androgen-secreting tumors.
What a low result can mean
Low testosterone in men can result from obesity, insulin resistance, sleep apnea, poor sleep, opioid or glucocorticoid use, chronic illness, heavy alcohol use, prior anabolic steroid use, pituitary disorders, testicular failure and aging. Low SHBG can make total testosterone appear low while free testosterone is normal.
What affects the result
Testosterone peaks in the early morning and is about 20-30% lower in the afternoon; test between roughly 7 and 10 am, ideally fasting, since glucose lowers it. Diagnosis of deficiency requires two low morning values. LC/MS/MS is more accurate than immunoassay, especially at low (female) levels. Interpret with SHBG, free testosterone, LH, FSH and estradiol.
Units and conversion
Usually reported in ng/dL.
- From nmol/L: multiply by 28.84 to get ng/dL
- From ng/mL: multiply by 100 to get ng/dL
- From pg/mL: multiply by 0.1 to get ng/dL
Also called on lab reports
Testosterone, Testosterone, Total, TESTOSTERONE, TOTAL, MS, Testosterone, Total, LC/MS, Testosterone, Serum, Testosterone Total, Testosterone, Total, LC/MS/MS, Testosterone, Total, Immunoassay
Related tests: Sex Hormones
This page is educational and does not replace advice from a healthcare professional.