A common reference for total testosterone in adult men sits roughly between 8 and 30 nmol/l. That number says little on its own. In the EMAS study, symptoms only clearly related to a value below about 11 nmol/l (Wu, 2010).
What strikes me every time: men fixate on a single figure. Your age, your lab and your symptoms together decide what that figure means.
The number is a starting point, not a verdict.
Below I walk through five life stages, from your twenties to past sixty. Each time with the same question: what changes, and when is low actually low?
What is a normal testosterone level?
For most adult men a normal total testosterone falls within their lab's reference range, often somewhere between 8 and 30 nmol/l. That range differs by laboratory and by measurement method. So always look at the reference range printed on your own result, not at a number from an article.
In a large international study, healthy men aged 19 to 39 sat between roughly 9 and 32 nmol/l, with a middle around 18 nmol/l (Travison, 2017).
The spread is wide. Two healthy men can differ a lot without either of them having a problem.
What exactly gets measured, you can read at total testosterone.
How much testosterone does a man have?
How much testosterone a man has depends on his age, his health and the time of day. Testosterone peaks in the early morning and drops as the day goes on. That's why blood is usually drawn in the morning, and why your GP reads the value alongside your symptoms.
The body doesn't make testosterone in a fixed amount. Sleep, stress, weight and illness push the figure up or down.
One measurement at the wrong moment can come out lower than your real average. How to have that measurement done well is covered in how to test testosterone.
1. Testosterone around 20-29: highest on average
In your twenties testosterone sits at its highest point on average. The fact that healthy men aged 19 to 39 ranged between roughly 9 and 32 nmol/l (Travison, 2017) mainly shows how broad "normal" is.
At this age testosterone plays into muscle, libido, bone and energy. A healthy man rarely notices anything special, precisely because the system runs smoothly.
Symptoms from low testosterone are rare here. If you do sit low, there's usually a specific reason, and you discuss that with your GP.
What I tell younger men: a low figure isn't something to ignore, but it's no reason to panic either.
2. Testosterone around 30-39: the decline begins
From roughly your thirties testosterone starts to fall slowly. In research it's about 1 to 2 percent per year (Feldman, 2002). That's slow, and you usually notice nothing for years.
If you do notice something, it's often subtle: slightly less recovery after training, a little less fire. That can fit testosterone, but just as easily fits a busy life and too little sleep.
Lifestyle in this stage often weighs more than age. Little sleep, a lot of belly fat and chronic stress can push your value down more than the calendar does.
Age is rarely the whole story.
Sometimes a deficiency plays along. Which ones those can be, you can read in deficiencies that can lower your testosterone.
3. Testosterone around 40-49: symptoms show up more often
Around forty more men report symptoms they link to testosterone: less energy, less drive, harder to build muscle. Yet the average decline is still gradual.
The tricky part is that these symptoms also fit a normal value. Poor sleep, stress and excess weight give the same picture.
That's exactly why I find a single measurement weak here. A value on a busy, badly slept morning can give a distorted picture.
My advice in this stage: tie the number to your symptoms, not the other way around. Free testosterone and SHBG sometimes add context the total alone misses.
4. Testosterone around 50-59: number and feeling diverge
Take two men of 55, both with a testosterone of 14 nmol/l. One trains, sleeps well and feels fine. The other is tired, irritable and has less drive. Same number, different story.
14 nmol/l falls within the reference range at most labs. Yet that says nothing about how you feel. So your GP looks at the whole, not at one value.
In this stage SHBG rises in many men. That can make your free, usable testosterone come out lower than your total suggests.
This is also the stage where men reach fastest for TRT stories. My advice: start with the whole picture, not with an advert.
5. Testosterone from 60 onward: lower, but not automatically too low
Past sixty testosterone sits lower on average than in your thirties. That's partly normal ageing. Lower therefore doesn't automatically mean "too low".
The EMAS study showed sexual symptoms only clearly related to a value below about 11 nmol/l (Wu, 2010). Above that line the association weakened quickly.
Many symptoms you attribute to testosterone at this age also come from sleep, medication or other conditions. A blood value helps sharpen that question, not answer it on your own.
What I tell older men: a mild decline belongs to the age. Persistent symptoms belong with your GP.
Why is "normal" so hard to define?
Normal is hard to define because labs use different reference ranges and measurement methods. Most Dutch labs also use one adult range, not a separate cut-off per age. So you compare your value with the reference range on your own result, and with your symptoms.
The NHG (Dutch College of General Practitioners) stresses that a testosterone value is always judged alongside your symptoms, not as a lone number.
| Life stage | What often changes | Why "normal" is hard to define |
|---|---|---|
| 20-29 | Levels sit at their highest on average | Wide spread between healthy men |
| 30-39 | Gradual decline begins | Lifestyle often weighs more than age |
| 40-49 | Symptoms show up more often | Symptoms and the number do not track together |
| 50-59 | More variation, SHBG often rises | Free testosterone can be lower than the total suggests |
| 60+ | Lower on average | Lower is not automatically "too low" |
See how elastic "normal" is? That's exactly why the reference range on your own lab result leads, not a table from an article.
If you want more background on your male hormones, look at our guide to testosterone levels and at the broader guide to hormonal health in men.
If you recognise the symptoms, read which signs point to low testosterone.
What can you do now?
Want your values in view with an assessment alongside? The Men Over 40 Panel measures your testosterone among other values, and a BIG-registered doctor looks along with you.
If you recognise yourself in this, discuss your result with your GP. Bring the reference range and your symptoms together, not just the figure.
References
- Travison TG, Vesper HW, Orwoll E, et al. Harmonized reference ranges for circulating testosterone levels in men of four cohort studies in the United States and Europe. J Clin Endocrinol Metab. 2017;102(4):1161-1173. PMID 28324103.
- Feldman HA, Longcope C, Derby CA, et al. Age trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts Male Aging Study. J Clin Endocrinol Metab. 2002;87(2):589-598. PMID 11836290.
- Wu FC, Tajar A, Beynon JM, et al. Identification of late-onset hypogonadism in middle-aged and elderly men. N Engl J Med. 2010;363(2):123-135. PMID 20554979.
- NHG (Dutch College of General Practitioners): a testosterone value is assessed in the context of symptoms. Dutch College of General Practitioners.
Disclaimer
Caliberhealth works with BIG-registered doctors who review your blood results. This article offers general information and does not replace medical advice from your GP or specialist. A blood test is a tool, not a diagnosis on its own. For persistent or serious symptoms, contact your GP, or call 112 in an emergency.
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