Under the American Urological Association (AUA) guideline, low testosterone is diagnosed with two early-morning total testosterone tests below 300 ng/dL, combined with symptoms or signs. A single result, at home or in a clinic, is a starting point rather than a diagnosis.
What the guideline says
The AUA guideline on testosterone deficiency was published in 2018 and has been updated since, and the AUA confirmed it was still valid in 2024. It sets out a few points that matter for anyone considering testing:
- A cutoff. Clinicians should use a total testosterone level below 300 ng/dL as a reasonable cutoff to support a diagnosis of low testosterone.
- Two tests. The diagnosis should be made only after two total testosterone measurements on separate occasions, both taken early in the morning. This is a strong recommendation, because levels fluctuate through the day and between days.
- Symptoms count. A clinical diagnosis of testosterone deficiency requires low total testosterone and symptoms or signs. A low number with no symptoms is not, by itself, a diagnosis.
- Lifestyle comes first. All men with testosterone deficiency should be counseled on lifestyle changes as a treatment strategy.
Symptoms that may prompt testing
Commonly discussed symptoms include low sex drive, low energy, erectile problems, and low mood. These are also caused by many other things, including poor sleep, stress, depression, medications, and other medical conditions. That is why a clinician looks at the whole picture rather than a single hormone value.
What this means for home tests
At-home kits can give you a baseline number. Treat it as information to bring to a doctor, not as a diagnosis. If a result is low, the guideline's approach is to repeat the measurement on another morning and look at symptoms. Results can also vary by lab and method, so using the same lab for repeat tests is sensible.
If you are trying to conceive
Tell your doctor before starting any testosterone treatment. The AUA guideline advises against giving testosterone therapy to men who are currently trying to conceive, because it can suppress sperm production.
What to do next
- If you have persistent symptoms, ask a clinician about testing rather than self-treating.
- Schedule tests for early morning, and plan for a repeat if the first result is low.
- In the meantime, the best-supported levers are on the research page: sleep and, for men with excess body fat, weight loss.
This article is general education, not medical advice. Talk to a clinician about testing and treatment. Medical disclaimer.