Low testosterone in Men: When should you test, and does testosterone replacement therapy help?

By Dr David Roberts, GP at Courtyard Health Clinic, Musselburgh

We are delighted to welcome Dr David Roberts, an experienced GP who has joined us at Courtyard Health Clinic. We are very excited to be working with him. In this article, Dr Roberts looks at low testosterone levels in men, how testosterone should be tested, and whether testosterone replacement therapy (TRT) is the right treatment.

Testosterone has become a much-discussed topic in men’s health. Social media, podcasts and online clinics increasingly promote testosterone testing and testosterone replacement therapy, sometimes as a solution for tiredness, reduced motivation, poor concentration or simply “not feeling yourself”.

Genuine testosterone deficiency is an important medical condition, and for appropriately selected men treatment can make a significant difference.

But testosterone is more complicated than a single blood test. A testosterone result is a starting point, not a diagnosis.

What are the symptoms of low testosterone in men?
Reduced sexual desire, loss of spontaneous or morning erections and erectile dysfunction are among the more specific symptoms of testosterone deficiency. Other features can include reduced muscle mass, reduced body hair, infertility, anaemia and reduced bone density.

Tiredness, poor concentration, low mood and reduced motivation are much less specific. They are important symptoms, but have many other possible causes.

This distinction matters. Rather than assuming these symptoms are caused by testosterone, a good assessment should consider the wider picture.

How should testosterone be tested?
A testosterone blood test should generally be taken in the morning, preferably before 11am and fasting, when levels are normally highest.

A low result should usually be repeated on a separate morning before making a diagnosis.

If testosterone is borderline, measuring sex hormone-binding globulin (SHBG) and calculating free testosterone can help with interpretation. This is particularly useful in men with obesity, where total testosterone may be reduced partly because SHBG is low.

Other tests, including luteinising hormone (LH), follicle-stimulating hormone (FSH) and sometimes prolactin, can help establish why testosterone is low and whether the problem originates from the testes, the pituitary gland or elsewhere.
There is therefore considerably more to assessing testosterone than simply labelling a result “normal” or “low”.

What testosterone level is too low?
There is no single number that should be considered in isolation.

UK professional guidance varies slightly, but there is good evidence that appropriately selected symptomatic men with testosterone below approximately 8 nmol/L can benefit from treatment. Conversely, evidence for benefit when total testosterone is above 12 nmol/L is limited.

Between these levels, interpretation becomes more individual. Symptoms, SHBG, calculated free testosterone, weight, medications and other health conditions all matter.

What causes low testosterone?
Sometimes there is an underlying problem affecting the testes or the hormones controlling them.

However, testosterone can also be suppressed by obesity, significant illness and certain medications, including long-term opioids.

Obesity is particularly important. Weight loss can substantially improve testosterone levels while simultaneously improving blood pressure, blood glucose, cardiovascular risk and overall health.

In some men, addressing the underlying cause may therefore be more appropriate than immediately starting testosterone.

Does testosterone replacement therapy work?
For men with genuine hypogonadism, meaning compatible symptoms together with repeatedly confirmed low testosterone, TRT can be effective.

The strongest evidence is for improvement in sexual desire and sexual function. Treatment can also improve anaemia, bone density and body composition in appropriately selected men.

The effect on general symptoms such as tiredness, mood and energy is less predictable. In major clinical trials, improvements in sexual function were clearer than improvements in fatigue and vitality.

Testosterone should therefore not be viewed as a universal treatment for tiredness or the effects of a busy life.

Is testosterone replacement therapy safe?
Modern evidence is reassuring, but TRT still requires appropriate assessment and monitoring.

The large TRAVERSE trial involving more than 5,000 men found that testosterone treatment did not increase the overall rate of major cardiovascular events compared with placebo during approximately three years of follow-up. Some individual adverse events were more frequent, however, and longer-term questions remain.

Testosterone can also increase the red blood cell count, so haemoglobin and haematocrit need monitoring. Prostate health and prostate-specific antigen (PSA) should also be considered appropriately before and during treatment.

Testosterone replacement therapy and fertility
One particularly important consideration is fertility. Taking testosterone suppresses the hormonal signals that stimulate sperm production and can substantially reduce fertility. Conventional TRT is therefore generally unsuitable for men actively trying to conceive.

Looking beyond the testosterone result
A man presenting with reduced energy, erectile dysfunction, loss of libido or declining physical performance may have testosterone deficiency.

But these symptoms can also provide an opportunity to look more broadly at cardiovascular and metabolic health, weight, exercise, sleep, alcohol, medication and psychological wellbeing.

At Courtyard Health Clinic, our approach is to interpret testosterone results within this wider context.

For some men, this may lead to further investigation and consideration of testosterone replacement. For others, addressing the factors affecting testosterone and overall health may be more appropriate.

The decision should be based on symptoms, properly performed testing and individual clinical assessment, not a single number on a blood test.

Testosterone assessment at Courtyard Health Clinic, Musselburgh
If you are concerned about low testosterone, our GPs can arrange a thorough assessment, including properly timed blood tests and a review of your wider health. Courtyard Health Clinic is based at Eskmills in Musselburgh, East Lothian, and is easily reached from Edinburgh. To book an appointment, call 0131 297 6655 or email office@courtyardhealthclinic.com.