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The Fitness Verdict

Hormones

TRT: What Men Should Know Before They Start

The clinics sell it as a switch that turns back the clock. The randomized trials tell a narrower story, with real tradeoffs attached. Here is the honest read before you sign up.

By The Fitness Verdict Editorial 8 min read
A serious middle-aged man sitting on an exam table in a clinic, forearms on his knees, waiting for lab results.

Every strip mall has a men's clinic now, and every one of them runs the same ad. Tired? Soft in the middle? Low drive? Come get your levels checked. The pitch sells testosterone replacement therapy as a switch that turns you back into the guy you were at 25.

Here is the verdict up front. TRT is a real medical treatment that helps a specific group of men who have both low testosterone on a blood test and symptoms to match. For those men, the benefits are modest and mostly show up in sex drive and mood, not in energy or strength. It is also a long-term commitment with real tradeoffs, including your fertility. Most men who walk into a clinic asking for it do not actually meet the bar, and the honest answer for them is unglamorous: sleep, training, and body fat.

Who actually qualifies

The Endocrine Society guideline is blunt about the diagnosis. You get labeled hypogonadal only when you have symptoms and signs that fit testosterone deficiency and blood levels that are clearly and consistently low. The test itself has rules. It should be a fasting total testosterone drawn in the morning, using a reliable assay, and it should be repeated on a separate morning before anyone writes a prescription (Bhasin et al., 2018).

One low reading after a bad week of sleep does not make you hypogonadal. Testosterone swings by time of day and takes a hit from illness, poor sleep, heavy drinking, and excess body fat. That is why the guideline calls for two confirmed morning measurements and then a workup to find out why the number is low. A pituitary problem, a testicular problem, and a beer gut are three different diagnoses with three different answers.

What the trials actually show

The best evidence in older men comes from the Testosterone Trials. Researchers randomly assigned 790 men aged 65 and up, all with testosterone under 275 ng/dL and symptoms, to testosterone gel or placebo gel for a year.

Sexual function improved. Sexual activity, desire, and erectile function all went up compared with placebo. Mood was slightly better and depressive symptoms slightly lower. Vitality, measured with a fatigue scale, did not improve at all. Walking distance did not improve in the trial designed to test it, though a small difference showed up when all participants were pooled (Snyder et al., 2016).

Read that again, because it is the part the clinic ads skip. In the flagship trial, testosterone did not fix fatigue. The men taking it did not feel more energetic than the men on placebo gel.

The heart question

For a decade the open question was whether TRT raised heart attack and stroke risk. TRAVERSE was built to answer it. Researchers randomly assigned 5,246 men aged 45 to 80, all with two low fasting testosterone readings and either existing heart disease or high risk of it, to testosterone gel or placebo.

Over a mean follow-up of about 33 months, major cardiac events happened in 7.0 percent of the testosterone group and 7.3 percent of the placebo group. Testosterone met the bar for noninferiority (Lincoff et al., 2023). That is genuinely reassuring, and it settled the biggest safety fear.

It did not come back clean, though. The testosterone group had more atrial fibrillation, more acute kidney injury, and more pulmonary embolism. Those are not nothing. Noninferior on heart attacks is not the same as harmless.

The blood sugar angle

The T4DM trial tested something different: 1,007 Australian men aged 50 to 74 with a big waistline, borderline testosterone, and either prediabetes or new type 2 diabetes. All of them went through a lifestyle program. Half also got testosterone injections for two years.

At two years, 12 percent of the testosterone group met the criteria for type 2 diabetes versus 21 percent in the placebo group. The benefit came on top of the lifestyle program (Wittert et al., 2021).

Now the catch from the same trial. A safety trigger for hematocrit above 54 percent, meaning blood thick enough to worry about, fired in 22 percent of the testosterone group and 1 percent of the placebo group. More than one in five men hit that mark. That is why hematocrit monitoring is not optional.

Bones went the wrong way

Testosterone improves bone density, so the assumption was that it would cut fractures. A subtrial of TRAVERSE followed 5,204 men for a median of 3.19 years and found the opposite direction. Clinical fractures occurred in 3.50 percent of the testosterone group and 2.46 percent of the placebo group (Snyder et al., 2024).

Better bone density on a scan did not translate into fewer broken bones. It is a useful reminder that a good-looking lab marker is not the same as a good outcome.

The fertility tradeoff nobody explains

This is the one that catches men off guard, and it is not a small side effect.

Sperm production depends on very high testosterone concentrations inside the testicles, far higher than what circulates in your blood. When you inject or rub on testosterone from outside, your brain reads your blood levels as fine and stops sending the signals that drive your testicles to produce. Testicular testosterone falls, and sperm production falls with it (Crosnoe-Shipley et al., 2015).

Men on TRT can drop to very low sperm counts, and some go to zero. It usually recovers after stopping, but recovery can take months to more than a year, and it is not guaranteed. The Endocrine Society flatly recommends against starting testosterone in men who are planning fertility in the near term (Bhasin et al., 2018). If kids are anywhere in your plans, say so out loud before you start, because there are other approaches your prescriber can discuss.

Who should not start

The guideline lists conditions where testosterone should not be started. Breast or prostate cancer. A palpable prostate nodule, or a PSA above 4, or above 3 if you are at higher risk, without a urology workup first. Already elevated hematocrit. Untreated severe sleep apnea. Severe urinary symptoms. Uncontrolled heart failure. A heart attack or stroke in the last six months. A clotting disorder (Bhasin et al., 2018).

If a clinic is willing to start you without a real history, a repeat morning lab, and a prostate and blood count check, that is a sales operation, not medical care.

It is usually a one-way door

Once you supply testosterone from outside, your own production winds down. Stop, and you often feel worse than you did before you started while your system tries to restart. Some men restart fine. Some take months. Some never fully get back.

Plan for it to be permanent. Ongoing monitoring is part of the deal: symptoms, side effects, testosterone levels, hematocrit, and prostate risk checks, especially in the first year (Bhasin et al., 2018).

What to do before you consider it

If your number is low but borderline, and your symptoms are fatigue and softness around the middle, the levers that move testosterone are the same boring ones that move everything else.

Sleep first

Short sleep drives testosterone down. Fixing five hour nights is free and has no hematocrit risk.

Drop the excess fat

Body fat converts testosterone to estrogen and drags levels down. The T4DM men were all carrying a big waist for a reason.

Lift and eat enough protein

Strength training will do more for how you look and function than a mid-normal testosterone level ever will.

Get honest labs, twice

Fasting, morning, repeated. If they come back clearly low both times, you have a real conversation to have with a prescriber, not a clinic.

The verdict

TRT is legitimate medicine for men with confirmed low testosterone and matching symptoms. The wins are real but narrower than advertised: better sex drive and erectile function, a modest lift in mood, and in one trial less progression to type 2 diabetes in heavy men. Energy did not improve. Fractures did not improve. Thick blood is common, fertility takes a hit, and stopping is not simple.

If you fit the criteria, work with a prescriber who tests properly and monitors you, and go in knowing what you are trading. If you do not fit the criteria, no dose of testosterone is going to outperform sleeping seven hours, losing the gut, and lifting three times a week.

References

Common questions

What testosterone level is considered low?

The Endocrine Society guideline calls for a fasting morning total testosterone measured with a reliable assay, then repeated on a separate morning to confirm. The large trials used cutoffs under 300 ng/dL and under 275 ng/dL to enroll men. One reading on its own does not settle it, because levels swing with time of day, sleep, illness, alcohol, and body fat. Talk to your prescriber about which cutoff and which assay they are using.

Does TRT give you more energy?

In the Testosterone Trials, it did not. Vitality measured on a fatigue scale showed no improvement over placebo after a year, even though sexual function did improve and mood improved slightly. If fatigue is your main complaint, testosterone is a poor bet, and sleep, iron, thyroid, and sleep apnea are worth ruling out first.

Does TRT make you infertile?

It suppresses sperm production in most men, sometimes down to zero, because outside testosterone shuts off the signals that keep testicular testosterone high enough for sperm to form. Production usually recovers after stopping, but it can take months to over a year and is not guaranteed. The Endocrine Society recommends against starting testosterone in men planning fertility in the near term. Raise this with your prescriber before you start.

Is TRT bad for your heart?

The TRAVERSE trial randomized 5,246 men at high cardiovascular risk and found testosterone was noninferior to placebo for major cardiac events over about 33 months. The same trial saw more atrial fibrillation, acute kidney injury, and pulmonary embolism in the testosterone group. So the big fear did not pan out, but it is not a free pass, and men with existing heart problems need a prescriber watching them.

Can you stop TRT once you start?

You can stop, but your own production has usually wound down while you were on it, and restarting takes time. Many men feel worse for a stretch after stopping than they did before starting. Some recover in weeks, some in months, and some do not fully return. Treat it as a long-term commitment and never stop abruptly without talking to your prescriber.

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