Dr Jeff Foster is a GP working in the NHS with a special interest in men’s health and testosterone. He is the author of Man Alive: The Health Problems Men Face and How to Fix Them (Piatkus, £14.99). He is also the medical director for H3 Health, a medical clinic specialising in hormone health.
The guys in your local gym have been peddling it for years as essential for muscle growth.
But in the past two decades, prescriptions for testosterone therapy (sometimes called TRT) have doubled. And it’s being marketed by direct-to-consumer campaigns for general health, sex drive and mood – not just big biceps.
That has also come with an increasing number of men looking to have their testosterone levels tested.
But while the hormone testosterone decreases with age, the drop might not be significant for all men, so not everyone will need it.
Plus, taking testosterone comes with risks – especially to heart health – if you’re the wrong candidate.
Is it all about sex and bulking up?
Testosterone does indeed contribute to the development of typically male characteristics – like, yes, a high libido and the growth of muscle tissue as well as face and body hair.
But people think they will become an over-sexed bodybuilder if they take it. That will only happen if you take too much, and if you don’t need it. If you’re medically tested and found to have low levels and you take it under a doctor’s supervision, your levels should just return to normal. That could include making it easier to build muscle and balancing and/or improving your sex drive.
It’s important to understand that testosterone impacts other areas too, especially those associated with your mood and brain, like attention, memory and focus.
It also affects many other bodily processes, like your metabolism. So having the right balance can give you more energy (not having enough can conversely leave you tired). It also contributes to healthy glucose levels.
Is the male menopause or andropause real?
These are media terms used to compare low testosterone with menopause. But low testosterone in men is very different to the menopause in women.
Firstly, not all men will show symptoms, whereas all women will go through the menopause at some point in their late 40s or 50s when their oestrogen levels dramatically drop. Then they’re likely to show symptoms and their periods eventually stop.
In men, testosterone levels naturally peak at age 30 and then drop by about one per cent every year. If you’re born with high levels and you’re physically active and look after yourself, you may never even notice the drop.
That decline in men can in fact be gradual or quick but symptoms won’t affect every man so it’s much harder to pick up.
The condition itself is known as testosterone deficiency or, technically, male hypogonadism (not very catchy).
What symptoms should I look for?
Low sex drive and muscle loss may be part of it, but in the early stages there can be other more subtle signs.
Most men with low testosterone will see changes in one or more of these areas:
A drop in mental sharpness and mood – they feel less happy, they’re grumpy and irritable, and less motivated at work. They may struggle to concentrate and be more forgetful than usual. They may also feel there’s no happiness in their relationship and they can’t be bothered fixing it.
Changes in their bodies – they might go to the gym but not gain as much muscle as they used to. They’re probably fatter despite doing the same amount of exercise.
Tiredness they can’t crack – They’re more tired than ever and sleep doesn’t seem to help. They don’t recover like they used to.
Do erection problems always mean low testosterone?
Erectile dysfunction (ED) isn’t just about testosterone. It’s often an early sign of heart disease – where the veins and arteries start to narrow – and that’s why it always has to be reported to a doctor.
Still, if you’re not having regular morning erections, you should be tested for low testosterone. Left untreated, it worsens so eventually men can get erectile problems. But that can be anything from not being as hard as it used to be to the near complete inability to get an erection.
The best question to ask yourself is: “When was the last time I had regular morning erections?” If you can’t remember, that’s a red flag for testosterone.
How common is low testosterone?
There are various studies showing the prevalence of testosterone deficiency among men ranging from about 12 per cent to up to a quarter of men. But not all men with low testosterone will need treatment, which is why it’s so important only to be seen by a doctor if you’re seeing symptoms.
If you have Type 2 diabetes though, get tested anyway. A paper published in The Lancet in 2021 found that 50 per cent of all adult men with Type 2 diabetes had low testosterone levels.
Can I get tested at my GP?
If you have symptoms you can go to your GP or a private clinic. The test is easy but many doctors (NHS and private) don’t know the difference between total testosterone and free testosterone, or know the latest recommendations on the normal range. It is possible to have normal total testosterone but low free testosterone, which is the active form of testosterone which regulates mood, libido and muscle mass.
These are the nuances that a doctor needs to know to get your levels right, which is why it’s best to see someone who has a special interest in testosterone.
Therefore many men are told levels are normal when they do not have the whole picture.
Overall, my advice is if you have any of the symptoms we’ve talked about here, you should get it looked into, even if you only have one symptom. Many patients present to me with only one symptom.
In short, a GP is a great starting point but don’t be put off looking further if the tests say normal and you still have symptoms.
What affects my testosterone production?
Age is the most important factor and accounts for more than 90 per cent of symptoms. But other things influence testosterone production.
These include obesity, Type 2 diabetes (see above), alcohol consumption, smoking, cancer treatments, antifungal therapies and even medical conditions like asthma and high blood pressure.
Will it keep my bones strong?
We naturally convert a small amount of testosterone to oestrogen. This is essential for keeping our bones dense. If we have low testosterone this means not enough oestrogen and men can get brittle bone disease.
Will I put on weight?
It’s possible to put on a small amount of weight when you start taking testosterone. Although this might be initially water, over time, most men reduce their body fat and increase their muscle mass which is heavier. So, they might show a higher number on the scales but look like they’re in better shape.
Will lack of sleep affect my testosterone?
You need around six to seven hours’ sleep a night for your brain to trigger a testosterone surge, which happens naturally in the morning (it’s why you get morning erections).
But you won’t get as much of that if you’re sleep deprived. So it’s important to keep a regular sleep pattern to maximise your own natural production.
Severe untreated obstructive sleep apnoea (when your breathing stops and starts while you sleep) can be made worse with testosterone. So anyone prescribing it should check for this first.
What happens if I stop taking it?
Most men that take testosterone will have to take it forever. We are replacing what your body can’t produce naturally so if you stop, your body will go back to what it was before.
As long as you do it at safe levels, you can come off and go back to what you were before.
For most people it’s not going to make you dependent. It will be like taking thyroxine for thyroid disease, insulin for diabetes or HRT for menopause.
Will it affect my fertility?
Taken in isolation, taking testosterone will decrease fertility in men. But there are treatments you can use in conjunction with it that can help to preserve your fertility. It makes it more complicated but it’s not impossible.
Will it increase my prostate cancer risk?
There is no evidence that testosterone replacement therapy causes prostate cancer. But conversely, if you already have prostate cancer and you take testosterone, then a malignant cell that was sensitive to testosterone could grow.
You should be tested for prostate cancer (using a blood test called a prostate-specific antigen or PSA test) before you take testosterone. This is why you need to get it from a doctor, not a commercial clinic online.
What’s the biggest risk?
Testosterone stimulates your body to make erythropoietin, an essential component in your blood. Too much of that can make your blood sticky and dense and more likely to clot, which can increase your risk of strokes and heart attacks.
All patients taking testosterone need to have their blood monitored closely by their doctors – ideally twice a year.
How is it taken?
You can take testosterone in two forms: a topical daily gel/cream taken once every couple of days or an injectable form taken once every nine to 12 weeks. The one that’s right is the one that suits you – a third of our patients will change their minds about what type to take after three to six months.
If anyone tells you taking testosterone in a certain form is the best way, they’re lying and probably trying to market a certain type to you.
What are the side effects?
At the start of treatment you might experience acne, breast swelling or ankle swelling but that should settle down. If the dose is mild, there are usually no side effects.
If you’re getting persistent breast tenderness or swelling you will need to talk to your doctor to find out why your body is converting the testosterone to oestrogen and you’re getting excess in your breast tissue.
Will it make me angrier?
It’s a Goldilocks effect. Men with low testosterone will be grumpy, irritable and snap more easily. Bring their testosterone levels back to normal and they usually feel better.
But likewise, when the dose is too high, they can get grumpy and angry as well. Get it just right and their tempers tend to level out.
Can lifting weights help?
In a small group of patients, lifestyle can make a difference. That means exercising hard – usually with weight training – losing weight and sleeping better.
In some of these cases, we might supplement with a bit of testosterone and that can kick-start their bodies into making it. But in the past 10 years I have treated over 1,000 patients and around 30 have managed to do this.
Any last bits of advice?
If you’re thinking of buying testosterone from someone in the gym or from a commercial clinic that doesn’t involve a full medical check and doctor’s supervision all along the way, I’ve got one word of advice: don’t.