When to Get Your Testosterone Checked: A Practical Guide

Testosterone testing has become a common topic in men's health conversations, but there is surprisingly little practical guidance available for the average man trying to decide whether he should get tested, when to do it, and what the numbers mean once he has them. This guide addresses the logistics of testosterone testing in straightforward terms.

Who Should Consider Testing?

The short answer: men with symptoms that are consistent with testosterone deficiency, particularly when those symptoms are persistent and not explained by an obvious alternative cause.

Major medical organizations, including the American Urological Association (AUA) and the Endocrine Society, do not recommend routine testosterone screening in asymptomatic men. There is no evidence that population-wide screening improves health outcomes. Testing is recommended when symptoms are present.

Symptoms that warrant consideration include:

• Persistent fatigue not explained by sleep, stress, or other conditions
• Decreased libido or sexual interest
• Erectile dysfunction
• Loss of muscle mass or strength despite regular exercise
• Increased body fat, especially around the abdomen
• Depressed mood, irritability, or difficulty concentrating
• Unexplained anemia
• Loss of bone density on a DEXA scan

Additionally, testing is appropriate for men with conditions known to affect testosterone production:

• Type 2 diabetes or metabolic syndrome
• Obesity (BMI above 30)
• Chronic opioid use
• Pituitary disorders or history of pituitary surgery
• History of testicular injury, surgery, or radiation
• HIV/AIDS
• Chronic kidney disease
• Use of glucocorticoid medications

When to Test: Timing Matters

Testosterone follows a circadian rhythm. Levels are highest in the early morning and can drop by 20 to 30 percent or more by the afternoon. For this reason, guidelines consistently recommend that blood be drawn between 7 AM and 10 AM for the most accurate result.

There is an age-related nuance here. In younger men (under 45), the circadian variation is more pronounced, making morning testing particularly important. In men over 65, the circadian fluctuation is somewhat blunted, though morning testing is still preferred for consistency and comparability.

Fasting is not strictly required for testosterone testing, but some evidence suggests that recent meals can acutely lower testosterone levels, particularly high-glucose meals. To minimize variables, many clinicians recommend fasting or at least avoiding a heavy meal before the blood draw.

Critical point: A single low result is not sufficient for diagnosis. Testosterone levels fluctuate day to day due to sleep quality, stress, illness, and other factors. Both the AUA and the Endocrine Society require at least two separate morning measurements showing low testosterone before a diagnosis of hypogonadism is made.

What Tests to Order

The minimum test is a total testosterone level. But for a more complete picture, the following panel is recommended:

Total Testosterone

This is the sum of all testosterone in the blood — bound to SHBG, bound to albumin, and free. It is the standard screening test. Most laboratories report a reference range of approximately 264 to 916 ng/dL, though ranges vary by laboratory and assay method.

Free Testosterone

Free testosterone represents the 2 to 3 percent of testosterone that is not bound to any protein and is immediately available to tissues. It can be measured directly (equilibrium dialysis is the gold standard) or calculated from total testosterone and SHBG levels. Direct immunoassay methods for free testosterone are less reliable and may over- or underestimate the true value.

Sex Hormone-Binding Globulin (SHBG)

SHBG is the primary binding protein for testosterone. High SHBG levels reduce free testosterone even when total testosterone is normal. SHBG increases with age, liver disease, hyperthyroidism, and certain medications. It decreases with obesity, insulin resistance, and hypothyroidism. Measuring SHBG helps interpret total testosterone in context.

Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH)

These pituitary hormones regulate testicular function. They help distinguish between primary hypogonadism (testicular problem, where LH and FSH are elevated as the pituitary tries to compensate) and secondary hypogonadism (pituitary or hypothalamic problem, where LH and FSH are low or inappropriately normal despite low testosterone). This distinction affects treatment decisions.

Additional Tests

Depending on the clinical context, your provider may also order:

• Prolactin. Elevated prolactin can suppress testosterone and may indicate a pituitary tumor.
• Estradiol. Important if gynecomastia is present or if testosterone replacement is being considered.
• Complete blood count. To check for anemia related to low testosterone and to establish baseline hematocrit.
• Thyroid function (TSH). Thyroid disorders can cause symptoms that mimic testosterone deficiency.
• Metabolic panel and HbA1c. To assess for diabetes, which is both a cause and consequence of low testosterone.

How to Interpret Results

Interpreting testosterone results is not as simple as comparing your number to a reference range. Here is what to keep in mind:

Reference Ranges Are Not Thresholds

A reference range is typically derived from the middle 95 percent of a population. Being at the bottom of the range does not necessarily mean you are deficient, and being just above a cutoff does not necessarily mean you are fine. The AUA defines low testosterone as below 300 ng/dL, but this is a guideline, not a cliff edge.

Context Matters

A total testosterone of 310 ng/dL in a 70-year-old man with no symptoms is a different clinical situation than the same level in a 42-year-old man with fatigue, loss of libido, and depression. Your provider should consider your symptoms, age, overall health, and free testosterone when interpreting results.

Trends Are More Informative Than Snapshots

A single testosterone measurement is a snapshot of one morning. Tracking levels over time — annually or every few years — provides a trend line that is far more informative. A man whose testosterone has declined from 600 ng/dL to 350 ng/dL over five years is in a different situation than a man who has been stable at 350 ng/dL for a decade.

Common Pitfalls in Testing

Several factors can lead to misleading results:

• Afternoon testing. Levels can be 20 to 30 percent lower in the afternoon. An afternoon draw may show a "low" result that would be normal in the morning.
• Acute illness or stress. Being sick, sleep deprived, or acutely stressed can transiently lower testosterone. Test when you are in your usual state of health.
• Ignoring SHBG. Total testosterone alone can be misleading. A man with high SHBG may have low free testosterone despite a normal total level. Conversely, a man with low SHBG may have adequate free testosterone despite a lower total level.
• Using unreliable free testosterone assays. Direct immunoassay methods for free testosterone are less accurate than equilibrium dialysis or calculated free testosterone. If your provider offers only an immunoassay, the result should be interpreted with caution.
• Testing only once. A single low result must be confirmed. Day-to-day variability can be significant.

What to Do With the Results

If your results are normal and you are asymptomatic, no further action is needed. You may choose to recheck in a few years to establish a trend, but there is no urgency.

If your results are normal but you are symptomatic, the symptoms likely have a different cause. Depression, sleep disorders, thyroid disease, and chronic stress should be explored.

If your results are low and you are symptomatic, the next step is a comprehensive evaluation to determine the cause of the deficiency and discuss treatment options with your provider.

If your results are borderline (between 250 and 350 ng/dL), consider repeating the test, checking free testosterone and SHBG if not already done, and having a thorough conversation with your provider about whether treatment is appropriate given your specific situation.

Building a Baseline

One of the most valuable things you can do is establish a baseline testosterone level while you are healthy and asymptomatic. If you later develop symptoms, having a prior value to compare against makes interpretation much easier. A man whose testosterone was 650 ng/dL at age 35 and is now 310 ng/dL at age 50 has experienced a significant decline, even though 310 ng/dL is technically above the AUA threshold.

Without that baseline, there is no way to know whether 310 ng/dL represents a decline for you or is where you have always been. This is one of the strongest arguments for proactive health tracking: it gives you context that a single measurement cannot provide.