Are modern men’s testosterone levels falling? What are the crucial symptoms to look out for? And why is men’s hormonal health so misunderstood?

To find out, Unfiltered spoke to testosterone expert Dr Geoffrey Hackett, a consultant in urology at Spire Little Aston Hospital. Dr Hackett is a former president of the British Society for Sexual Medicine and the lead author of the 2023 UK guidelines on testosterone and sexual dysfunction in men. He has specialised in the treatment of low testosterone and erectile dysfunction and has published more than 150 papers.

Headline-making studies suggest men’s testosterone levels are declining. Are they right? And, if so, why is this happening?

Yes, it is declining. Obesity is one [cause]. The increase in diabetes. The increase in drugs that lower it: opiate prescribing, SSRIs [antidepressants], antipsychotics and also phthalates [in plastics] that are supposed to be an important issue in certain countries. Also, if we’re living longer, then we’ve got longer with age-related testosterone decline.

Studies have shown that anywhere from 2-30% of men today have low testosterone. Why do these estimates range so widely?

The reason for the 2% is that that comes from the endocrinology [hormone] world, where they talk about classical hypogonadism, which is testicular failure, where you have low testosterone [caused by an underlying medical condition]. And they view every other form of low testosterone that’s secondary, or compensated, which is what we’re most often talking about now – relating to the obese, diabetes, or drug-related and lifestyle-related – as being optimally treated with lifestyle change [not testosterone therapy].

Some studies suggest one in five men now have sub-optimal levels of testosterone – low but not low enough to warrant hormone therapy – due to poor health and lifestyle factors.

Yes, I think that was shown by the European Male Aging Study [EMAS] which was done when we were still part of Europe, so I don’t think we’ve changed since Brexit!

The problem nowadays is that as soon as a patient starts to mention those [signs of low testosterone], the GP’s hand is going for the prescription pad for an antidepressant”

Dr Geoffrey Hacket

Low testosterone is diagnosed through a combination of blood tests – typically a reading below 8nmol/L of blood – and symptoms. What are the key symptoms to look out for?

Erectile dysfunction, low libido and lack of morning and evening erections are the big three. Those are the ones that came out from the European Male Ageing Study… And the real importance of those is that, even in this day and age, doctors are still reluctant to ask about erections. I can’t believe that almost 30 years since Viagra was thought of, we’re still not able to do this.

Early morning erections are the best predictor, because what goes on in a sexual relationship can be affected by a lot of things – the emotion, the relationship, and whether the partner is enjoying it. But with morning erections, this is nature’s way of keeping the tissues perfused. But widowed or single guys would just never be asked because doctors are probably not going to wade in and ask about their erections. Because it might offend. But with morning erections, we should be brave enough to ask about [them].

With a lot of the other symptoms of low testosterone, like hot flushes, they come at lower levels, probably lower than 8nmol/L. So if somebody’s getting flushes and night sweats, that tells you that the level is going to be pretty low. With some other symptoms like fatigue, poor concentration, low mood and feeling sleepy, they could overlap with other things, particularly depression.

The problem we have nowadays is that as soon as a patient starts to mention those, the GP’s hand is going for the prescription pad for an antidepressant. Or as soon as they’ve mentioned two of those. And then, of course, the over-prescription of the antidepressants further lowers the testosterone and worsens the sexual function. But there’s no guilt felt by the GP. Mea culpa. But if you’d been treating somebody with an underactive thyroid with antidepressants, you’d be worried that you might be sued.

Even what defines a “low testosterone” reading seems to range hugely. Usually it is 8nmol/L, based on NHS standards, but sometimes it is up to 12nmol/L. Why is it hard to pin down this key number?

I think it’s even worse than that, because if you look at reference ranges for laboratories, they often say something like 6.75nmol/L. And that’s purely an arbitrary level, sent to them by the manufacturers, who tested 100 people and told you where the bottom 2.5% and the top 2.5% were. Now, if you said, well, let’s apply that [same method] to blood pressure or cholesterol, you’d only be talking about people with blood pressure who were likely to have a stroke next week. Whereas we would really want to treat the people in the milder levels, because you’ll actually get more benefit. And if we only treated the 2.5% most obese people, they are probably beyond treatment because they’re morbidly obese and less likely to respond. So there is still debate over ‘where’ you treat someone for testosterone.

You’ve probably seen [Dr Michael] Zitzmann’s paper where he showed that as the [testosterone] level falls, more symptoms develop. So if you’re talking about below about 15, you’re getting a bit of lack of enjoyment of life, and your mojo might have gone a bit. Well, if somebody talks to a GP like that, the GP’s mojo probably went 10 years ago, so he’s not sympathetic to this guy who says: “When I run a marathon, I’m getting more tired in the last five miles.” He’s switched off and he is looking out the window. And if you were the person at NHS England setting the level for treatment, would your priority be to switch on middle-aged men’s mojos? No, you’d be only interested in the level that you’ve got for preventing diabetes.

Might the cut-off for testosterone treatment change in years to come?

The new BSSM [British Society for Sexual Medicine] guidelines suggest taking the level (for treatment) up to 14, from 12, based on the T4DM study in Australia. This study showed that if you treated men with pre-diabetes pwho had testosterone levels] up to 14, you could reduce the progression to full diabetes by over 40%. And that would be vitally important, because that’s going to save huge costs from any healthcare system. Diabetes is very expensive to manage. But that study has still not hit the headlines because it came out during COVID.

There’s no such thing as the male menopause… we’ve got to try and get over the message that everybody thinks we’re talking about a male menopause, as though men are trying to get a bit of the action that women have got – and the sympathy”

Dr Geoffrey Hackett

Should men expect their testosterone to decline naturally with age?

Well, I keep expecting to be contacted by Premier League clubs to be given a trial every season! But you’ve just got to look at the fact that the value of a footballer begins to decline from about age 28. Cristiano Ronaldo hasn’t taken a pay drop, even at 38, but he will have to eventually. So there’s always got to be an age-related decline. And if everybody is seeking to reverse that, as Tom Cruise seems to have done, then I think we’re mostly going to be disappointed, aren’t we?

Why is testosterone so misunderstood?

There’s a lot of politics here because of the perception that testosterone is something to do with bodybuilding. As soon as you mention it, the first picture that somebody gets is of somebody like Arnold Schwarzenegger. And that’s what we’ve got to lose.

We’ve also got to try and get over the message that everybody thinks we’re talking about a “male menopause”, as though men are trying to get a bit of the action that women have got – and the sympathy. And if I’m ever giving an interview, I always say: let me make it clear that there’s no such thing as the male menopause. And then the article will come out that I’ve given an interview on the male menopause.

From injections to gels, what are the advantages and disadvantages of the different treatments available to men with low testosterone?

It is largely down to personal choice. I tell patients about the features, and I can see within 30 seconds which way they are going. Generally, if someone is concerned about side effects, they might think: I will start with the gel, because I can stop it and it will be out of my system. But the trouble is, if it is going to take a few weeks to work, we always expect a quick fix. So they will probably give up after a week or two. Whereas if you use an injection, that lasts 12 weeks. So even if you think a week later that it hasn’t done anything, suddenly a month later the man’s wife will say: I think you are better.

What are the benefits and dangers of using private clinics for treatment?

One of the problems is that deficiency in the NHS has led to the growth of private clinics. And what happens there is that the motivation, quite understandably, of a private clinic is to make money. And the way you make money is not through the consultation. It’s by the long-term provision of product that gives you a profit. Now when a GP or a specialist like myself writes a prescription for Testogel or Nebido, they get it from the pharmacy. But these (private) clinics make their money by a 10 times markup on using a cheap, old-fashioned formulation of enanthate or cypionate. And that’s where their revenue is.

And then they begin to produce their own evidence about (the drug offering) a greater benefit than anything you can get from your doctor. Because there’s a huge commercial gain for doing that. And also, the problem with it is that it probably is the truth that you do get a more immediate high because they’re shorter-acting. But if I went in to see a patient with pain, and I gave them heroin, they would get great relief. But if I went in every few days and gave heroin for a year, I probably would have created more problems than I’d solved. So, the immediate hit isn’t necessarily the best thing for you to take in the long term.

The private clinics are more interested in the older, cheaper, generic, short-acting [testosterone] injections because of the potential to make more money”

Dr Geoffrey Hackett

Which are the most common treatments prescribed on the NHS?

You’re unlikely to get tablets on the NHS because tablets are still a bit of a problem. Although we seem to have some that are safer, there’s always a bit of a fear about long-term effects on the liver. Also, in getting tablets to last 24 hours, they’re likely to need to be given three times a day, so you’re going to get peaks and troughs. So it does tend to come down to gels and the long-acting injections.

And as we said earlier, the private clinics are more interested in the older, cheaper, generic, short-acting injections because of the potential to make more money. And because potentially they have a shorter action. But one of my concerns with them is that men are great risk-takers. And I’ve seen this just with prescribing ED (erectile dysfunction) drugs. If you give Sildenafil (Viagra), and it doesn’t work the first time, the guy will take more the second night. So if you give a guy some ampules of testosterone – enanthate or cypionate – and he wants to feel better by next week, he’s probably going to double the dose without the physician giving him instruction.

Now, in contrast, one of the things about using the Nebido injection is that it’s given every 10 or 12 weeks. So it’s a slow build up and it’s often given by a nurse. And with the gels, it is also very difficult to overdose on the gel because nobody’s going to start smearing twice or three times a volume over a large area. And it’s also prescribable, so there’s going to be an alarm if you’re suddenly asking for huge amounts.

Should the NHS do more to address male hormonal health?

Well, there’s a bit of philosophy that comes in here, as to how far you should alter the effects of ageing… When you’ve got an NHS that is struggling to keep going, does the burden have to fall on the public themselves if they want to aspire to something better? And this is a fundamental question that we have got to come to grips with. Because if you look at the fact that the three major symptoms of low testosterone are erectile dysfunction, loss of morning erections and loss of libido, some would say, well, the planet is not going to self-destruct if these things fall with age.

I think one of the problems is that the NHS has to buy into it. And GPs won’t change unless things are in their Quality and Outcomes Framework [QOF – an annual reward and incentive programme for GP practices]. They believe that a lot of other stuff that they get may be commercially-driven.

But if it’s in the QOF, then they’ll believe it because it also comes with some cash. And one of my hobby horses has been that every GP gets about three times as much for a woman patient as he or she does for a man, because of the breast and cervical screening, HRT [hormone replacement therapy] and contraception, which all come with extra payments. There’s actually no male-related payment at all. Even efforts to have prostate cancer screening have failed, because nobody could get their head round whether there’ll be too many false positive PSA [prostate-specific antigen] tests, which will result in over-treatment. There are various models that other countries have brought into this, but we are reluctant to go to that next step.

What other areas of testosterone research do you think are neglected?

Low testosterone post-COVID is another thing that we haven’t touched on, but there’s a lot of papers on that. The problem is that pre-COVID we weren’t measuring testosterone levels, so nobody knows what the testosterone level was in enough men before they come in with COVID. But we know that levels plummet during acute COVID. And we know that about 20-30% don’t recover their testosterone levels afterwards. And erectile dysfunction seems to be three times more common. But nobody’s asking about this in long COVID clinics, and the patients don’t mention it because they’re just pleased to be alive. So those are issues that are being neglected.