To TRT or not to TRT for low testosterone?

Clinically low testosterone can lead to a range of issues, including low energy, depressed mood, and brain fog, and it can be treated with TRT. However, a growing number of men are turning to testosterone therapy not for medical reasons but to maintain their physique and productivity. Can it help?

Research has shown that if a man’s testosterone levels are too low, the body’s main stress response system, known as the HPA axis, can become dysregulated. File picture: iStock

FOR MUCH of his early 30s, Aidan*, a Cork-based factory worker, was finding himself plagued by social anxiety.
“I couldn’t leave the house, even to go to the barbers or go into town for food,” he recalls. “I was trapped at home, and life was just going by without me.”

He was prescribed antidepressants but things only began to change after he spotted a story about Robbie Williams claiming that his mental health had improved after starting testosterone replacement therapy (TRT), a therapeutic treatment administered via injections, gels, and patches, which aims to artificially boost levels of the hormone.

His GP was sceptical, especially as Aidan was only 34 at the time, but after visiting the Optiman clinic in Dublin, a blood test revealed that he had low levels of so-called free testosterone, or the amount of the hormone circulating around in the bloodstream, which is available for your body to use.

After receiving a testosterone injection from a doctor at the clinic, Aidan initially noticed little difference, but after five weeks, that all changed.

“It was like a light came on in my head,” he says. “I started to look at life a bit differently. 

I’d previously dropped out of college, but since going on TRT, I’ve gone back and done a degree, and completely changed my career path.

Research has shown that if a man’s testosterone levels are too low, the body’s main stress response system, known as the HPA axis, can become dysregulated.

This can lead to an exaggerated reaction to ordinary, everyday stresses, a lack of motivation, and increased levels of anxiety. 

“This also often causes middle-aged men to become more irritable, and have issues with things like clarity of thought or brain fog,” says Bray-based GP Emmett Byrne, founder of the Optiman clinic. “But it’s very reversible.”

Muscle growth, blood sugar control, and sleep regulation

The male sex hormone testosterone is most commonly associated with libido and masculinity, but it’s also involved in a wide array of bodily functions from metabolism to muscle growth, blood sugar control, and sleep regulation.

However, at some point in midlife, testosterone typically begins to decline. This can occur at a greater rate in some men than others, influenced by genetic factors and also a man’s general state of health, with conditions such as obesity, hypertension and type-2 diabetes making testosterone decline more likely.

Robbie Williams claimed that his mental health had improved after starting Testosterone replacement therapy (TRT).

Studies have found that approximately 30% of men between the ages of 40 and 79 have clinically low testosterone levels, and such deficiencies have been linked to a plethora of symptoms ranging from low energy levels to increased irritability, brain fog, and a diminished ability to handle intense exercise. 

Correcting this through TRT has been linked with both short and long-term health benefits, with some comparing it to the hormone replacement treatment, which can help women both during and post-menopause.

Byrne says that men treated with TRT typically experience boosts in energy and libido, reduced anxiety, greater ability to gain and retain muscle tissue, and a general sense of vitality.

“There’s no other medication I’ve dealt with which yields the same improvements in quality of life that TRT can offer,” says Byrne. 

“I was in the supermarket, and a patient and his wife came over, gave me a hug, and said thank you. You don’t get that, generally speaking, for lowering someone’s cholesterol and blood pressure.”

Social media influence

The use of testosterone injections or supplements to improve health and wellbeing has become more mainstream in recent years, particularly on social media. But this greater awareness is not entirely positive.

In 2021, the popular American podcaster Joe Rogan dedicated an episode to TRT, in which he discussed his own regimen with Stanford University neurobiology professor Andrew Huberman. 

He described beginning TRT in his late 30s, initially with creams before progressing to injections every three days.

Rogan’s colossal fame and notably muscular physique in his late 50s have undoubtedly helped fuel the association between testosterone and muscle mass. In recent years, reports have described a burgeoning black market in gyms with testosterone injections being commonly sold alongside various anabolic steroids.

Psychologists describe this trend as concerning. 

“Accessing testosterone over the counter or in a gym genuinely worries me,” says Dean McDonnell, a member of the Psychological Society of Ireland. “It’s important to flag that short-term gains can sometimes result in long-term loss.”

Dr Emmett Byrne: 'Men who wish to conceive in future need to be careful about taking testosterone.'

It’s a point also highlighted by Byrne, who says that people taking testosterone without adequate medical supervision are often unaware of some of the risks.

“When you’re receiving testosterone from an external source, you tend to shut down your own natural levels,” he says. “That can lower your sperm count to the point where you can not make sperm.”

Because of this, Byrne stresses that any man who wishes to conceive at some point should be very careful about taking testosterone, as it can lower sperm count. 

He explains that not every man who comes to medical clinics like Optiman will be considered eligible for TRT, and the therapy is only prescribed following a series of assessments, including blood tests to check whether a patient’s testosterone levels are clinically low, screening questionnaires, medication review and a physical examination. 

In many cases, the underlying cause of the symptoms can be totally unrelated to testosterone.

“People sometimes walk in with what they think is testosterone deficiency, and the cause is completely different,” says Martin Rourke, a GP and men’s health specialist who co-runs Optiman with Byrne. 

“Anything could be causing you to be tired. The job is to figure out whether it’s testosterone, anaemia, a thyroid problem, or whatever.”

Even when TRT is prescribed, it also requires ongoing medical supervision. While Byrne says concerns that TRT might increase the risk of prostate cancer or cause its progression have been disproven, it isn’t suitable for people with obstructive sleep apnoea, for example, as it may increase the frequency of episodes.

The other main risk is that it can concentrate red blood cells in the circulation and slightly increase the risk of clots, which clinicians can detect on a blood test and address by lowering the dose accordingly.

“There’s a risk-benefit ratio in every medication that you take,” says Byrne.

Unrealistic expectations

While TRT can be life-changing for some men, McDonnell is still worried that the combination of social media influencers and the continual focus on new ways to enhance productivity is creating an unrealistic view about what normal ageing looks like.

He points out that while TRT is very much a legitimate medical treatment for clinically diagnosed testosterone deficiency, it is not an anti-ageing therapy or a shortcut to perpetual youth.

“A gradual reduction in testosterone is a normal part of ageing,” he says. “As men reach midlife, they may notice certain changes. But add performance culture, gym aesthetics, productivity expectations, and masculinity norms, and it becomes easy to interpret those changes as a loss of vitality. Testosterone can start to feel like the missing piece.”

He believes that it’s important for men in their 40s, 50s, and 60s to first consider the broader picture and how factors such as diet, stress, burnout, sleep deprivation, overtraining and general lifestyle strain might be impacting their general health before turning to medication.

“The risk arises when we look for quick biochemical fixes instead of addressing the foundations of health,” he says.

Rourke says lifestyle improvements themselves can yield improvements in testosterone, particularly in men who are overweight, sedentary, or have underlying metabolic health conditions. 

“Weight loss has the greatest effect, with studies showing that a 10-15% reduction in body weight can raise testosterone by several nmol/L,” he says. 

“Exercise and reducing alcohol intake also produce smaller but consistent improvements, largely through better metabolic health, rather than direct stimulation of testosterone production.”

At the same time, he says there’s a limit to what lifestyle changes can achieve on their own, especially in men who have clinically low testosterone levels.

“In men whom I see, lifestyle measures typically plateau and rarely bring [testosterone] levels from low into the mid-normal range,” says Rourke. 

Lifestyle change is essential to overall health but does not always replace the need for testosterone therapy when true deficiency is present.

In testosterone-deficient men, Byrne is also clear that the benefits of treatment comfortably outweigh the risks. 

He points out that boosting testosterone back to clinically normal levels helps protect against sarcopenia, the age-related muscle loss which is linked to an increased risk of physical frailty.

This also improves your overall body fat-to-muscle ratio, which increases your body’s ability to absorb and metabolise blood glucose, lowering your risk of developing diabetes.

Perhaps most crucially, it can also give men the boost they need to help them lead a healthier lifestyle. “It’s the testosterone that gives you the energy to get up and go to the gym at the end of the working day, which improves cognition, overall fitness, and all the other benefits that exercise can give,” says Byrne.

Now 44, Aidan has been taking TRT for more than a decade and is convinced it has completely changed his life. He saw such an improvement in his anxiety that he was able to stop taking antidepressants, and pursue a new career in the manufacturing of medical devices.

“It’s changed my career path, and I just look at life differently now,” he says. “I’d lost so many years of my life because of the anxiety, and now I’ve been able to get moving on.”

*Name changed