What are normal testosterone levels by age?

Testosterone is one of the most important hormones in your body. Present in both men and women, it is responsible for a wide range of bodily functions, including sexual function, metabolism, and mood. Low testosterone, also called hypogonadism, can affect any man at any age. That’s why, if you think you are experiencing low testosterone, it is important to talk to a healthcare professional.

How is testosterone measured?

For men, the normal range should be between 12 and 30 nmol/L, the laboratory can also calculate free testosterone.

A Total Testosterone level less than 12 nmol/L or a free testosterone (FT) level <0.225 nmol/L usually requires therapy in the presence of symptoms:

• A TT level above 12 nmol/L or an FT greater than 0.225 nmol/L does not require therapy

• Levels between 8-12 nmol/L may require a trial of testosterone therapy, minimum six months based on symptoms

If treatment is required the aim is for a target TT level of 15–30 nmol/L to achieve an optimal response.

Testosterone over time

A man’s testosterone levels are not static. During puberty, a man’s testosterone levels peak, and they remain high throughout the early twenties and thirties. From around age 40, testosterone levels start to decrease, at around 1-2% per year. Your lifestyle also informs how much testosterone you need, and produce. Even in your early twenties, if you live a sedentary lifestyle, you are likely to have lower testosterone levels. But, in your fifties, if you are living an active lifestyle, you are likely to need (and produce) more testosterone.

Testosterone levels also fluctuate throughout the day. Levels peak in the morning, before decreasing as the day progresses. When healthcare providers are testing for hypogonadism, they tend to ask for two blood tests, taken on different mornings, to decrease the likelihood of an anomalous reading.

Ultimately, the ideal testosterone levels for you will depend on a range of factors, including your age, lifestyle and overall health. Speaking to a healthcare provider, like the friendly experts here at Ted’s Health, is the best way to make sure that your testosterone levels are where they should be.

Written by Ted’s Health and medically reviewed by Professor Mike Kirby