No man needs the shot
3 min read - all sources to this journal are listed at the bottom.
Some men's bodies, because of illness or a condition they were born with, can't produce testosterone on their own. They need help, and they get it. This article isn't about them.
It's about the middle-aged man. He's tired by the afternoon. He's put on weight around his stomach over the last ten years. He sleeps badly and knows it. And somewhere, he's seen that you can get your testosterone measured, that the number might be a little low, and that there's an injection for that.
In the US, that business has been running for thirty years. Clinics that measure, diagnose, and treat — often for cash. It's now starting to evolve in Europe.
Our claim is simple: for that man, the injection isn't the best solution. It's just the easiest one.
It's a stance, not a treatment. But it's cheaper.
The Decline Is Slow. That's What Makes It Hard to See
Testosterone declines by roughly 1 to 2 percent a year from the mid-thirties onward. That's not much. Over twenty years, though, it's enough that you notice it — and enough that you start looking for an explanation.
What almost no one gets told is how much of that decline has nothing to do with age at all.
Sleep
Here's the number worth remembering. In one study, ten healthy young men slept eight hours a night, then five hours a night for eight nights. After that week, their daytime testosterone had dropped between 10 and 15 percent.
That's roughly what ten years of normal aging would cost them.
One week. That's all it takes. And it runs the other way too: testosterone is produced mainly while you sleep, and production tracks how long and how well you sleep. Sleep isn't good advice alongside the hormone. Sleep is where the hormone gets made.
Weight
Fat tissue isn't passive. It contains an enzyme that converts testosterone into estrogen. The more fat you're carrying, the more of your own testosterone gets converted into something else before it has a chance to work.
That's why weight loss is the most predictable thing a man can do for his testosterone. Across different approaches — low-carb, intermittent fasting, Mediterranean — the gain lands in roughly the same place: about 3 nmol/L for every ten kilos lost. The method matters less than most people think. The weight is almost the whole story.
It's also why the international medical societies say a man with excess weight and a low testosterone reading should lose weight first. Not as a suggestion alongside treatment. As the first thing to try.
Exercise
This is where we need to be precise, because it's where most articles on this topic get it wrong. When you do a heavy lift — a squat, a deadlift, a big compound movement — your testosterone rises. That's well documented. But the rise lasts hours, not months. When researchers have measured men's resting testosterone after weeks and months of strength training, the resting level is largely unchanged.
So strength training raises your testosterone acutely. It doesn't raise it chronically.
Even so, exercise is one of the three most important tools you have. For two reasons, both more important than the number itself.
The first is that exercise protects your metabolism, and with it, your weight.
Muscle is the tissue that burns the most energy, and the tissue that takes up the most sugar from your blood. Lose muscle through your forties and fifties — which you will, if you do nothing — and it gradually gets easier to gain weight and harder to lose it. And weight, as we just saw, is the most direct lever on testosterone there is. So exercise does affect the hormone, just indirectly: it keeps you able to hold your weight.
The second reason has to do with what testosterone actually does.
A hormone does nothing on its own — it has to bind to a receptor in the muscle cell before anything happens. In a study of 49 men who trained for twelve weeks, researchers found no relationship between the men's blood testosterone and how much muscle they built. What they did find a clear relationship with was how many androgen receptors sat in their muscles.
The hormone in the blood predicted nothing. The receptor in the muscle predicted everything.
That means two things. It explains why two men with the same testosterone reading can experience very different things. And it explains why pouring more hormone into a system is a questionable strategy when the hormone is rarely the bottleneck.
Diet
No food contains testosterone. But there are two things about diet worth knowing.
Don't eat low-fat.
When researchers have compared low-fat diets against higher-fat diets, testosterone comes out lower on the low-fat one. This holds especially for men eating a Western diet, and shows up most clearly in the trials where the low-fat diet was also vegetarian. Testosterone is built from cholesterol. Cut fat too aggressively and you remove the raw material.
Get enough zinc.
Zinc is the only micronutrient with a convincing, direct link to testosterone. In one small trial, four young men were put on a zinc-poor diet for twenty weeks; their testosterone fell to roughly a quarter of its starting level. Nine older men with low zinc were given supplements for six months, and their testosterone nearly doubled. Notice what that means — and what it doesn't. It shows that zinc deficiency lowers testosterone, and that it can be corrected. It doesn't show that more zinc helps a man who's already getting enough. It probably doesn't. Zinc is abundant in oysters, shellfish, meat, cheese, nuts, and pumpkin seeds. If you eat plant-based, pay closer attention — zinc from plants is absorbed less efficiently.
And then the most important thing about diet, which has nothing to do with any single food: whatever diet keeps your weight down is the diet that does the most for your testosterone. Whatever else you call it.
What an Injection Does to the Body
Testosterone works. That's not in question. The question is what comes with it.
The body regulates its own production based on how much it detects in the blood. When the hormone comes from outside, it shuts down its own. Sperm production stops, and the testicles shrink. For some men, it starts again once they stop. How fast — and whether it does at all — is individual, and it can take years.
The blood gets thicker. Testosterone increases red blood cell production, and that's the most common reason a dose has to be lowered or paused. It's why treatment requires regular blood tests, not just a prescription.
Some of the extra testosterone gets converted into estrogen — the same mechanism as in fat tissue, just with more raw material to work with. In some men, that produces breast tissue.
If you're predisposed to hair loss or breakouts, it speeds up. If you have sleep apnea, it can get worse. And if you have urinary issues, that's one of the things that needs checking before you even start.
A large trial of just over 5,000 men looked at the heart. There weren't more heart attacks or strokes among the men who got testosterone. But there were more cases of irregular heart rhythm and blood clots in the lungs. And the men in that trial had symptoms and measured low testosterone — they weren't healthy men looking for an edge. Whether the same holds for that group, nobody knows, because it's never been studied.
And Then the Number Everything Rests On
Most of your testosterone circulates bound to a carrier protein and isn't active. Only the free portion does anything. That protein rises with age and falls with excess weight — which means a single total-testosterone number can point the wrong way in either direction.
That's why the guidelines require at least two measurements, taken in the morning and fasted, before anyone makes a diagnosis.
One measurement taken mid-afternoon isn't a diagnosis. But it's often enough for a prescription.
if you decide to get an injection you need to Ask these Ten Questions before your first injection
If you decide to go ahead anyway, take this list with you. A doctor who can answer all ten calmly and specifically is one you can trust. One who gets impatient has already given you an answer.
1. Did we measure this correctly — and enough times?
The guidelines require at least two blood tests, taken in the morning and fasted. If my diagnosis is based on one test taken in the middle of the day, it wasn't made properly.
2. Have we ruled out what could explain the number without treatment?
Excess weight, poor sleep, heavy alcohol use, illness, and certain medications all lower testosterone. Have those been ruled out before we conclude it's age?
3. Which side effects reverse if I stop — and which don't?
This is the single most important distinction in the whole conversation. Ask for the list split into two.
4. How much of the hormone converts to estrogen in me — and are we measuring it?
Some of the testosterone you're given converts to estrogen. Ask directly whether estradiol is part of your blood work, how often, and what happens if it rises.
5. Can I develop breast tissue — and what do we do if it happens?
Ask whether it goes away on its own if the dose is lowered, or whether it needs treatment or surgery. The answer depends on how long you wait, which is why the question needs asking now.
6. What happens to my hair?
Testosterone accelerates hereditary hair loss. Ask whether it can be slowed again if you stop — and be prepared that the hair you've lost won't come back.
7. Can I still have children — and should I bank sperm before we start?
Treatment stops sperm production. For some men it starts again; for others it takes years. If there's even the slightest chance you'll want children, this is the question to ask before the first injection, not after.
8. What do we do about my prostate and my urination?
Ask what gets checked before starting, what gets monitored along the way, and what happens if you start needing to get up at night.
9. How often will I need blood tests, and what are we looking for?
Testosterone thickens the blood, and that's the most common reason treatment needs adjusting. If there's no fixed schedule for blood tests, there's no treatment plan.
10. What happens if I stop — and how long do we expect this to continue?
Your own production is shut down while you're in treatment. Ask how you'll feel in the months after you stop, and whether the plan is for this to last the rest of your life. It's rarely a question that gets asked, and it's almost always the most expensive one.
What We Can't Say
We should be honest about where the limits of what we know actually sit.
The sleep study was ten young men over eight nights. The effect is large and the mechanism is solid, but nobody has followed a middle-aged man who fixes his sleep over the course of a year and measured where he ends up.
And no one has ever put the two paths head to head. We don't know whether a testosterone number you've raised through sleep, weight loss, and exercise gives you exactly the same thing as a number raised with an injection. That trial hasn't been done.
What we do know is that one path has a known list of consequences, and the other doesn't.
Three Things
Prioritize your sleep. It's where in the body the hormone gets made, and the only thing on this list that costs nothing. Consistency matters more than perfection — the same bedtime every night beats one good night on the weekend.
Manage your weight. It's the most predictable thing you can do for your testosterone, and it works regardless of which diet you choose. Don't eat low-fat, and get enough zinc.
Exercise. Not because it raises the number — it doesn't, not lastingly — but because it maintains your muscle mass, protects your metabolism, and by doing so makes the first two things possible to sustain.
Three things. None of them can be billed for.
The cheapest treatment is still the one nobody can make money from.
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Sources
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