Quick Guide

The free and total testosterone test measures two values from a single blood draw: total testosterone (all forms of testosterone in the blood) and free testosterone (the unbound, active fraction of testosterone). The total testosterone test includes both free testosterone and testosterone that is bound to proteins, such as sex hormone-binding globulin (SHBG) and albumin.

If you’re testing because of fatigue, low sex drive, or unexplained mood changes, schedule your blood draw before 10 AM. Testosterone peaks between 7 and 10 AM and drops 20 to 30% by afternoon. An afternoon draw can read meaningfully lower than a morning draw in the same person on the same day. If morning collection isn’t possible, ask your lab whether a later draw is acceptable and note that afternoon results may read lower than your true level.

About the Free and Total Testosterone Test

Purpose of the test

You might consider this test when symptoms suggest a testosterone imbalance, when you’re monitoring hormone therapy, or when a condition like hypogonadism (when the body doesn’t produce enough testosterone) or PMOS (formerly PCOS) is suspected.

Here’s why measuring both values together matters. Most male testosterone in the blood is secreted by the testes, with a small amount from the adrenal glands. About 50%-68% is weakly bound to the protein, albumin, and 30%-45% strongly bound to SHBG (sex hormone-binding globulin). Free testosterone makes up only 2%-3% of total testosterone. In premenopausal women, the ovaries produce a much smaller amount of testosterone, with approximately 25% bound to albumin and almost 70% bound to SHBG. Free (unbound) testosterone (2%-3%) is the most active form and is readily available. The loosely albumin-bound portion can easily detach from albumin and become available when needed. Together, they form bioavailable testosterone.

A total testosterone test result can be within the normal reference range, yet the free and/or albumin-bound testosterone levels may actually be low, masking a real imbalance. The dual measurement is more informative than total testosterone by itself.

Testosterone declines roughly 1% per year after age 30 in men, according to the Cleveland Clinic. That makes it useful to separate normal aging from hypogonadism. Untreated low testosterone is linked to bone loss, metabolic changes, and fertility problems. This test doesn’t diagnose hypogonadism or PMOS on its own, and it doesn’t measure LH (luteinizing hormone), FSH (follicle-stimulating hormone), or SHBG.

The test serves two purposes:

  • Diagnosis: Consider testing if you have fatigue, low sex drive, loss of muscle mass, irregular periods, or excess facial hair, suggesting a testosterone imbalance.
  • Monitoring: Tracks testosterone during TRT (testosterone replacement therapy) or gender-affirming hormone therapy, helping check that levels reach their target range.

What does the free and total testosterone test measure?

This panel covers two markers from a single blood sample processed at a CLIA-certified lab.

  • Total Testosterone: The total amount of testosterone in the blood, including both protein-bound and unbound forms.
  • Free Testosterone: Only the unbound testosterone that’s immediately available for your body to use.

Two main methods measure testosterone:

  • Immunoassay: More common, faster, and less expensive. It can overestimate testosterone at low concentrations, making it less accurate for women and people on TRT.
  • LC/MS-MS (liquid chromatography-tandem mass spectrometry): The reference standard. More accurate at low levels and recommended by the Endocrine Society for women, people on TRT, and anyone with low testosterone. It takes longer to process.
  • Equilibrium Dialysis: a highly sensitive method used to directly measure free testosterone.

Free testosterone is usually reported as a calculated value from total testosterone, SHBG, and albumin. Most commercial labs use this approach. Direct measurement by equilibrium dialysis is the gold standard, but it isn’t generally used in routine testing because it is a more complex method in terms of time and expense.

When should I get a free and total testosterone test?

Consider testing if any of these apply:

  • Fatigue, low energy, or unexplained mood changes
  • Decreased sex drive or sexual function concerns
  • Loss of muscle mass or changes in body composition
  • Irregular or absent periods, or excess facial or body hair
  • Fertility concerns, including low sperm production
  • A suspected diagnosis of hypogonadism or PMOS
  • Ongoing TRT or gender-affirming hormone therapy that needs monitoring

There’s no universal screening recommendation for testosterone. The Endocrine Society’s clinical practice guideline on testosterone therapy recommends testing only when symptoms are present or a clinical reason exists. Some groups do benefit from periodic checks:

  • Men over 40 with symptoms of low testosterone
  • Adults on TRT, every three to six months
  • People with PMOS, every six to 12 months
  • Adults on gender-affirming hormone therapy, every three to six months during active therapy
  • Anyone with fertility concerns, per a reproductive specialist’s guidance

How It Works

How to get tested

This test is ordered through a healthcare provider, clinic, or hospital lab. Your provider sends you to a lab for the blood draw, and results come back through the ordering provider’s patient portal or office. No urine samples, swabs, or physical exams are involved.

At-home test kits are available for some hormone tests. Kits include instructions, collection materials, and prepaid shipping. Results are delivered through a secure online portal.

Before the test

Schedule your draw before 10 AM. Testosterone follows a daily (diurnal) rhythm, peaking between 7 and 10 AM. Waiting until the afternoon can produce a result 20 to 30% lower than your true morning level, as noted by the National Library of Medicine.

Fasting requirements vary by lab. Some require eight to 12 hours of fasting. Others don’t require fasting at all. Confirm your lab’s requirements when you schedule.

A few things to avoid before your draw:

  • Intense exercise in the 24 hours before testing (it can shift testosterone temporarily)
  • Alcohol in the 24 to 48 hours before testing (it can suppress testosterone)
  • Poor sleep the night before (sleep deprivation lowers testosterone)

Keep taking prescribed medications unless your provider says otherwise. Tell the lab technician about any supplements or hormones you’re taking. DHEA, testosterone supplements, and some herbal products can affect your results.

During the test

  • Bring a photo ID and your order confirmation. Check in at the lab or clinic.
  • A phlebotomist draws blood from a vein in your arm, usually the inside of the elbow. You’ll feel a brief pinch.
  • The draw takes a few minutes. A small bandage covers the site. Keep it on for at least 15 minutes.

You can leave right after. There’s no recovery time. Mild bruising at the draw site is normal and usually fades within a day or two.

Call your provider if you notice lasting pain, swelling, redness, or any sign of infection at the site.

After the test

Results are typically ready within one to five business days after the lab receives your sample, though timing can vary by lab. Immunoassay results tend to come back in one to three business days. LC/MS-MS results may take four to seven business days.

Results come back through the ordering provider’s patient portal or office.

What Do My Results Mean?

Your results report total testosterone in nanograms per deciliter (ng/dL) and free testosterone in picograms per milliliter (pg/mL) or ng/dL, depending on the lab. The table below shows approximate reference ranges. Your lab report will list the specific ranges it uses.

Ranges vary by lab, method, and age. Review results with your provider.

Several factors shape how your provider reads these numbers: time of collection, fasting status, your SHBG level, age, and any conditions you have. Elevated levels of SHBG can occur with aging, hyperthyroidism, liver cirrhosis, extreme dieting, and some medications (including certain anticonvulsants and estrogen-containing medications). This, in turn, can cause a decrease in the free testosterone level, even when the total testosterone level is normal. A decrease in SHBG can occur with obesity, hypothyroidism, insulin resistance, Type 2 diabetes, steroid/anabolic use, Cushing’s Syndrome, and PMOS. As SHBG decreases, less testosterone is bound, resulting in an increased level of free testosterone, yet the total testosterone level may be within normal range.

If your total testosterone is within the normal range

Both values fall within the lab’s reference range. That’s reassuring. But it doesn’t automatically mean everything is balanced. If your symptoms haven’t resolved, ask your provider about checking free testosterone and SHBG separately. High SHBG can mask a real shortage of active hormone.

If your total testosterone is low

A result below the lab’s reference range may suggest hypogonadism. One low result isn’t enough to confirm it. Providers typically repeat the test on a separate morning, since illness, stress, and some medications can temporarily suppress testosterone.

If a second test confirms low levels, follow-up often includes testing for luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin. Together, these tests help figure out whether the cause is primary (the testes aren’t producing enough) or secondary (the brain isn’t sending the right signals). Treatment depends on the cause and may include TRT, lifestyle changes, or addressing what’s causing it.

If your total testosterone is high

High total testosterone is less common. It’s worth investigating.

In men, it’s most often linked to anabolic steroid use, adrenal tumors, or certain medications. Symptoms can include acne, aggressive behavior, prostate changes, and lower sperm production.

In women, high testosterone is more commonly tied to PMOS or adrenal disorders, as described by the National Institute of Child Health and Human Development. Symptoms can include irregular or absent periods, excess facial or body hair (hirsutism), acne, and hair thinning. Follow-up often includes imaging and hormone panels such as LH, FSH, and DHEA-S (dehydroepiandrosterone sulfate).

If your free testosterone is low but total testosterone is normal

This pattern confuses most people. It’s the main reason measuring both values matters.

Total testosterone looks fine, but most of it is bound to SHBG and biologically unavailable. The biologically active fraction, free testosterone, is actually low. Your tissues aren’t getting enough free testosterone even though the overall amount in your blood appears adequate.

The most common cause is high SHBG. Conditions that raise SHBG include aging, hyperthyroidism, liver disease, and certain medications. You can have all the classic symptoms of low testosterone, like fatigue, low libido, and muscle loss, while your total testosterone sits squarely in the normal range.

The standard next step is an SHBG test. Some providers also measure albumin and calculate bioavailable testosterone. This scenario is exactly why the dual measurement is more useful than total testosterone alone.

FAQs

Why does my testosterone result look different depending on when I tested?

Testosterone follows a daily rhythm, peaking in the early morning and dropping through the afternoon. A draw at 2 PM can read 20 to 30% lower than one at 8 AM in the same person. That’s why morning collection is recommended and why comparing results from different times of day isn’t reliable.

Can lifestyle factors like diet or exercise affect my testosterone levels?

Yes. Chronic overtraining, significant calorie restriction, obesity, heavy alcohol use, and poor sleep are all linked to lower testosterone. Acute intense exercise can temporarily raise it, which is why you should avoid strenuous workouts 24 hours before testing. Addressing lifestyle factors is often part of the plan for mildly low testosterone.

What is SHBG, and why does it matter for my results?

SHBG (sex hormone-binding globulin) is a protein that tightly binds testosterone and makes it unavailable for your body to use. When SHBG is high, free testosterone can be low even if total testosterone looks normal. Your provider may order an SHBG test if your results show this pattern.

Is this test the same as a total testosterone test?

No. A total testosterone test measures only the overall amount of testosterone, including bound and unbound forms. The free and total testosterone test adds the free testosterone measurement, showing how much is actually available. The two-value panel is more informative when symptoms don’t match total testosterone results.

How often should I retest if I'm on testosterone replacement therapy?

Most providers retest every three to six months during active TRT to check that levels are in the target range and adjust dosing if needed. Once levels are stable, the interval may extend. Follow your provider’s specific schedule.

What is the difference between primary and secondary hypogonadism?

Primary hypogonadism means the testes aren’t producing enough testosterone on their own. Secondary hypogonadism means the brain (the pituitary gland or hypothalamus) isn’t sending the right signals to the testes. Telling them apart requires LH and FSH testing, and the distinction affects which treatments make sense.

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