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The exact cut-offs for normal testosterone levels in men vary, but estimates typically range from 270–1,070 ng/dL. According to the American Urological Association (AUA), having a value below 300 ng/dL is a “reasonable cut-off” to be diagnosed with low testosterone (AUA, 2018). It’s a large spectrum, and many healthy guys fall at different places within this range. Because when it comes to testosterone levels, “healthy” means something different to everyone. (For comparison, healthy testosterone levels in women are much lower.)
What determines testosterone levels?
Your testosterone levels depend largely on three factors:
- Existing medical conditions
It is commonly reported that testosterone levels peak in the late teens/early 20s and then decline by about 1% per year thereafter. Some research supports these statements, such as one study that found testosterone levels peaked at age 19 (Kelsey, 2014). Levels do then decline, but the exact amount they decline each year—and whether this is primarily driven by age or other factors—is less clear.
Testosterone levels fluctuate
Testosterone levels also fluctuate throughout the day. Testosterone peaks in the morning and dips later on. That’s why it’s better to get your testosterone levels checked between 8 a.m. and 10 a.m. Before a diagnosis of low testosterone can be made, levels are checked at least twice (Snyder, 2020).
Symptoms of low testosterone
According to the AUA, symptoms of low testosterone include tiredness, irritability, depression, reduced interest in sex, reduced lean muscle mass, and erectile dysfunction (Urology Care Foundation, n.d.). If you think you may have low testosterone, talk to a healthcare provider.
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
- American Urological Association (AUA). (2018). Evaluation and Management of Testosterone Deficiency (2018). Retrieved April 24, 2020 from https://www.auanet.org/guidelines/testosterone-deficiency-guideline
- Kelsey, T. W., Li, L. Q., Mitchell, R. T., Whelan, A., Anderson, R. A., & Wallace, W. H. B. (2014). A Validated Age-Related Normative Model for Male Total Testosterone Shows Increasing Variance but No Decline after Age 40 Years. PLoS ONE, 9(10). doi: 10.1371/journal.pone.0109346. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/25295520
- Snyder, P. J. (2020). Clinical features and diagnosis of male hypogonadism. Retrieved April 24, 2020 from https://www.uptodate.com/contents/clinical-features-and-diagnosis-of-male-hypogonadism?search=low testosterone diagnosis&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H219147875
- Urology Care Foundation. (n.d.). What is Low Testosterone? Retrieved April 24, 2020 from https://www.urologyhealth.org/urologic-conditions/low-testosterone
Dr. Mike is a licensed physician and the Director, Medical Content & Education at Ro.