Is It Age, or Is It How We Live? What's Happening to Men's Testosterone

If you've ever looked into what happens to men's hormones in midlife, you'll have come across the comforting version. Testosterone drops by about 1 to 2 percent a year from around the age of 30, slowly and gently, and that's just part of getting older.

I've been quietly questioning that for a while now. The figure itself may well be right for the average man today. What bothers me is the word “normal” that tends to get attached to testosterone decline in men, because the more research I read, the less it looks like ageing and the more it looks like the way we live.

I first started to question this after a male client had lost his zest for life and had experienced extreme stress in the workplace, what was going on at the root of the issues?

So I've pulled together the evidence that's been shaping my thinking. I'm calling what I'm seeing an earlier-onset pattern of andropause. That isn't a medical term, and I'm not pretending it is. It's an observation, and I'll be honest throughout about where the evidence is solid and where it's still thin.

Testosterone decline in men: one snapshot versus a whole life

The Massachusetts Male Aging Study followed men in and around Boston from the late 1980s into the 2000s. When the researchers compared younger and older men at one point in time, testosterone seemed to drop by only around 0.4 percent a year with age. But when they followed the same men over the following years, they found it was dropping by about 1.6 percent a year, four times faster.[1][2]

The difference comes down to who you're measuring. A 'snapshot' lines up different men side by side, whereas following one man over the years shows what actually happens to him as life goes on around him, giving a clearer picture of the situation.

The researchers' own explanation was that poor health over the following years, may have sped the decline up. In that same study, men in good health (no long-term illness, no regular prescription medicines, not obese and not drinking heavily) had androgen levels 10 to 15 percent higher.[1]

A review in 2022 went a step further. Wittert and Grossmann concluded that in men without obesity, unhealthy habits or certain medicines, testosterone tends to falls very little until well into old age. Much of what we put down to 'getting older', they argue, is really belly fat, medication and lifestyle.[3]

So yes, 1 to 2 percent a year may be accurate for the average modern man. I'm just not convinced we should be calling it 'normal'.

Each generation is starting from a lower point

What really caught my attention was this - The Boston team also compared men of the same age who were tested in different years. A 60-year-old tested in the late 1980s had higher testosterone than a different 60-year-old tested in the mid-1990s. With age taken out of the picture, levels were still dropping by about 1.2 percent a year over the course of the study.[2]

They did check the obvious explanations. More obesity, more medication and less smoking (smoking tends to nudge testosterone up, which is about the only nice thing anyone has ever said about it - but definitely not a reason to take the habit up!! ) didn't account for it. Their best guess was something in the environment, or something about the generation of men being born, that their data simply didn't capture.[2]

An Israeli study of more than 100,000 men tested between 2006 and 2019 found the same thing in most age groups. Even at 21, when testosterone is at its peak, average levels fell by around 10 percent over that time, and once again rising obesity didn't seem to explain it.[4]

Put a lower starting point together with a steeper slope and a man gets to the point of feeling it sooner. That's what I mean by earlier onset. What's behind the generational drop is still an open question. Chemicals in our environment that mimic oestrogen are one possibility I want to come back to in another piece, but the research hasn't settled it yet.

Nourish, Sleep and Peace: what the evidence points to

When I built The Foundation Flow™, my approach to hormone health, I built it around three pillars: Nourish, Sleep and Peace. Most of the time I'm talking about this with women in perimenopause. What struck me as I gathered this research is that the three things that seem to be pulling men's testosterone down line up with those three pillars almost exactly.

Nourish: food and weight

Nourish is about nutrition as a whole: enough protein, plenty of vegetables, proper meals and an honest look at alcohol. Blood sugar is one important part of that picture, and it's where some of the clearest research on men's testosterone sits.

Low testosterone and type 2 diabetes are closely tied together. Studies have found low testosterone in up to 40 percent of men with type 2 diabetes.[5] The link runs both ways through visceral fat, the fat that settles around the organs. Lower testosterone makes it easier to put that fat on, and that fat then pulls testosterone down further, so it can quickly turn into a loop.[6]

The encouraging news comes from the same research. A major review concluded that for an overweight man with type 2 diabetes and lower testosterone, the first step should be lifestyle: losing weight and getting more active. When those changes work, testosterone goes back up.[6]

Sleep

Most of a man's daily testosterone is released while he's asleep. In one small but striking study, healthy young men were limited to five hours' sleep a night for a week. By the end of it their daytime testosterone was 10 to 15 percent lower, which the researchers compared to ageing by 10 to 15 years. Their mood and energy dipped a little more each day as well.[7]

There were only ten men in that study, so I don't want to lean on it too heavily. But five hours a night will sound very familiar to a lot of working men (and, frankly, to a lot of the women lying awake next to them).

There's another layer to this that I find fascinating. People are having children later than they used to. In England and Wales, the average age of fathers reached 33.9 in 2024, up from 32.1 twenty years earlier.[8] So the broken-sleep years of early parenthood now tend to land later in a man's life, closer to the point where testosterone is already drifting down. And those years last longer than you might think. A large German study found that neither mothers' nor fathers' sleep fully recovered for up to six years after their first child.[9]

Becoming a father also lowers testosterone in its own right, and that part may well be by design. In a study of more than 600 men in the Philippines, those who became fathers saw their levels drop noticeably, especially the ones doing the most hands-on childcare.[10] The researchers see it as the body shifting gear towards caring for a child, which I find rather lovely - more on this in a future 'field notes' piece

The concern is what gets piled on top: years of shorter sleep, work and money pressure, and a later start, all landing on a man whose starting point may already be lower than his own father's was. - And I'll come back to this in a separate piece as well, because there's a lot more to say.

Peace: stress

How stress affects testosterone is well understood. When stress hormones stay high, they turn down the whole chain of signals between the brain and the testes that tells the body to make testosterone.

What surprised me is that a short burst of stress can actually push testosterone up for a while. A 2023 study of 67 young Swiss officer cadets found that both cortisol and testosterone rose during a stressful group test and a short field exercise. Over the first 12 gruelling weeks of their officer training, though, their morning testosterone fell, and it only recovered as the course came to an end.[11]

The body copes well with short, sharp stress. It's the long, grinding kind that wears it down.

Most men aren't in officer training, of course. But years of work pressure, money worries, ageing parents and broken sleep can keep stress hormones raised in much the same way, often with no end of course in sight.

Where blood sugar fits

You might have noticed blood sugar keeps cropping up. Food has the most direct effect on it, but it doesn't stop there. In one study, healthy young men who slept just four hours a night for six nights handled sugar noticeably less well,[12] and stress hormones are designed to push blood sugar up so we've got fuel to run or fight. So a man who eats well but is short on sleep and under constant pressure can still find his blood sugar working against him.

That's why I don't see the three pillars as separate boxes to tick. They're one connected picture, and blood sugar is one of the threads running through all of it.

Why this belongs in the men's health conversation

In November 2025, England published its first ever Men's Health Strategy.

It covers a lot of important ground: mental health, suicide, cancer including prostate cancer, and heart health. Hormones, though, only get a passing mention.[13]

The overlap is hard to ignore. Low mood, irritability, mood swings and low energy are all recognised signs of andropause.

Low testosterone is linked with:

• Metabolic syndrome

• Type 2 diabetes

• Higher risk of heart disease.

And a 2025 survey of UK clinicians agreed that testosterone deficiency is under-recognised, with many men going undiagnosed. That survey was funded by a company that makes testosterone treatments, which is worth knowing, but the idea of men slipping through the net certainly matches what I hear.[14]

If you're a man noticing any of these changes, or a partner noticing them in him, please have a conversation with your GP rather than writing it off as just getting older.

Where this meets the Hormonal Phase Gap

This is also why I keep coming back to couples. In The Hormonal Phase Gap I described her oestrogen as a wave and his testosterone as a long, quiet flatline. Neither of them is wrong about what they're seeing, but both are wrong about why.

If his flatline can start earlier than either of them expected, opening the gap earlier. She might be in her early forties, years away from what she thinks of as menopause, and he might be in his forties as well, with no idea that anything hormonal is going on for him at all. Two people changing at the same time, without any understanding or explanation.

What I'm not saying

I want to be straight with you about the limits here, because they matter.

"Earlier-onset andropause" is my observation, not a diagnosis. You won't find it in a medical textbook. It's a pattern I think is worth naming, and worth testing properly.

We also don't know yet which way round it goes. Low testosterone might help contribute to conditions like type 2 diabetes, or it might simply be a sign of poor health generally. Researchers still disagree, and some describe it as a marker of poor health rather than a cause - what came first? [6]

Some of the research has commercial backing, too. Several studies raising awareness of low testosterone are funded by companies that sell testosterone treatments. That doesn't make them wrong, but I've pointed it out wherever it applies. And the sleep study was tiny, ten men for one week. It points in a direction, but it doesn't prove anything on its own.

So what can a man actually do?

The hopeful part of all this is that so much of it is within reach, and the same three pillars give a man somewhere practical to start.

For Nourish, I suggest regular, proper meals built around protein, vegetables and good fats, fewer sugary snacks and drinks, and an honest look at alcohol, which can lower testosterone in its own right.

For Sleep, I recommend treating it as non-negotiable rather than the first thing to go when life gets busy, and if there are small children in the house, taking turns with your partner so you both get some proper stretches.

For Peace, find whatever genuinely lets the alarm switch off for a while, whether that's a walk, time outdoors, breathing practices or simply talking things through with someone.

Movement weaves through all three. I suggest regular activity you actually enjoy, some strength work to build and keep muscle, and not overdoing it, because pushing hard for years without enough food and rest can work against testosterone too. If you can, save the really hard sessions for earlier in the day. Gentler exercise in the evening is fine, but a flat-out session within an hour of bed can make it harder to drop off.

And please, see your GP. If you recognise yourself in this piece, or you recognise your partner, ask about a testosterone blood test. It's usually taken in the morning, when levels are at their highest, and your GP can look at the wider picture. If you take any medication, speak to your prescriber before changing anything. I can help with the foundations, but I don't diagnose and I'm not a replacement for your doctor.

I've been saying this for a while, and now I've got the evidence to back it up. Men's hormones respond to how men live, which means there's something we can actually work with.

Rhu x

References

1. 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):589-98. PubMed

2. Travison TG, Araujo AB, O'Donnell AB, Kupelian V, McKinlay JB. A population-level decline in serum testosterone levels in American men. J Clin Endocrinol Metab. 2007;92(1):196-202. PubMed

3. Wittert G, Grossmann M. Obesity, type 2 diabetes, and testosterone in ageing men. Rev Endocr Metab Disord. 2022;23(6). doi:10.1007/s11154-022-09746-5. Abstract

4. Chodick G, Epstein S, Shalev V. Secular trends in testosterone: findings from a large state-mandate care provider. Reprod Biol Endocrinol. 2020;18:19. Full text

5. Quang LM, Kalhan A. Cardiovascular benefits and risks of testosterone replacement therapy in hypogonadal men with type 2 diabetes mellitus and/or the metabolic syndrome: a systematic review. Br J Diabetes. 2018;18:141-6. (The "up to 40%" figure is from its introduction, citing Kapoor et al 2007 and Dhindsa et al 2004.) Full text

6. Grossmann M. Low testosterone in men with type 2 diabetes: significance and treatment. J Clin Endocrinol Metab. 2011;96(8):2341-53. PubMed

7. Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011;305(21):2173-4. Full text

8. Office for National Statistics. Births in England and Wales: 2024 (refreshed populations). 27 August 2025. ONS

9. Richter D, Krämer MD, Tang NKY, Montgomery-Downs HE, Lemola S. Long-term effects of pregnancy and childbirth on sleep satisfaction and duration of first-time and experienced mothers and fathers. Sleep. 2019;42(4):zsz015. PubMed

10. Gettler LT, McDade TW, Feranil AB, Kuzawa CW. Longitudinal evidence that fatherhood decreases testosterone in human males. PNAS. 2011;108(39):16194-9. Full text

11. Testosterone and cortisol responses to acute and prolonged stress during officer training school. Stress. 2023. doi:10.1080/10253890.2023.2199886. Abstract

12. Spiegel K, Leproult R, Van Cauter E. Impact of sleep debt on metabolic and endocrine function. Lancet. 1999;354(9188):1435-9. PubMed

13. Department of Health and Social Care. Men's Health Strategy for England. 19 November 2025. GOV.UK

14. Foster J, Wright P, Rao PM, et al. Improving the recognition, diagnosis, and management of male testosterone deficiency across the NHS: a Delphi consensus. J Sex Med. 2025;22(8):1390-8. Funded by Besins Healthcare (UK). Warwick repository