Deep Dive

Is Low T Behind Your Energy Crash?

A guide for men who want answers – not just another prescription

As a urologist, I see a lot of men who don’t feel quite like themselves anymore – lower libido, more fatigue, softer erections, stubborn weight gain, or just a general sense that something’s off.

Naturally, the question comes up:

The answer is usually yes – but the more important part is what comes next:

What do we do with that result – and what else should we be looking at?

In this newsletter, I’ll walk you through:

• Labs that are actually useful

• Testosterone testing must dos

• Looking deeper to see what’s going on under the surface

• And a simple script to use with your doctor to get the conversation started

Because for a lot of men, the hardest part isn’t the blood draw – it’s breaking the ice.

Labs Don’t Diagnose – They Start a Conversation

We treat numbers and symptoms.

A lab result might support a diagnosis, but it can just as easily reflect normal variation – or a level you’ve had your whole life. 

I’ve seen plenty of men with testosterone in the low or low-normal range who feel great. 

And others with “normal” numbers who feel flat, foggy, or disconnected.

Labs are a snapshot in time. For many markers – like testosterone – we look at patterns, context, and how you feel.

And sometimes, what looks like a hormone issue is actually poor sleep, burnout, or chronic stress. 

That’s why lab work should open the door to better questions – not jump straight to treatment.

Testosterone Testing: Do It Right

If we’re going to test testosterone, let’s do it properly:

• Timing matters – draw blood around 8 a.m., when levels peak

• Repeat the test – at least twice, on separate mornings

Don’t stop at total T – be sure to include:

• Free testosterone – this is the small percentage of testosterone that’s not bound to proteins in your blood and is available for your body to use. Think of it as the “active” testosterone that can affect your muscles, energy, and sex drive

• SHBG (sex hormone-binding globulin) – this is a protein your body makes that binds to testosterone in your bloodstream, essentially "locking it up" so it can't be used. Higher SHBG means less free testosterone is available, even if your total testosterone looks normal.

If testosterone is low and symptoms are present, we may follow up with:

• Prolactin – a hormone typically associated with milk production in women, but men produce it too. When levels are too high in men, it can decrease testosterone production and affect sexual function.

• LH and FSH – these are hormones produced by the pituitary gland that signal the testes to produce testosterone and sperm. Low levels might indicate the communication issue is "upstream" from the testes.

• PSA (prostate-specific antigen) - A protein produced by the prostate gland. Higher levels can indicate prostate enlargement, inflammation, or in some cases, cancer. It's important to check before starting testosterone therapy – especially in men over 50.

• Estradiol – a form of estrogen that men also produce, typically by converting testosterone. Too much can cause symptoms like breast tissue growth or affect libido and energy levels.

Thinking About Kids?

If fertility is a current or future goal, talk about that first. 

Testosterone replacement can suppress sperm production.

There are options – but they require planning.

When Testosterone Isn’t the Whole Story

Sometimes testosterone is normal – but something still isn’t right. That’s when we zoom out.

If these labs haven’t been done recently through primary care, we might consider:

• Fasting insulin – a test that measures insulin levels when you haven't eaten. High levels suggest your body is producing extra insulin to manage blood sugar, which can be an early sign of metabolic issues before diabetes develops.

• Lipid panel – check cholesterol and triglycerides

• A1c  (glycated hemoglobin) and fasting glucose – a blood test that shows your average blood sugar level over the past 2-3 months. It helps identify if you have or are at risk for diabetes, which can affect hormones and sexual function.

• Sleep quality – often more revealing than another blood test

• TSH (thyroid-stimulating hormone) – a hormone that regulates your thyroid function. Thyroid issues can cause symptoms that mimic low testosterone, like fatigue and low mood.

If you snore, wake tired, or feel foggy during the day, a sleep study might help more than a prescription.

Sometimes It’s Vascular

ED isn’t always about hormones. The penis is a small vessel organ – and often the first to show signs of early cardiovascular disease.

That’s when I often loop in primary care or cardiology. In the right cases, we may consider:

• hs-CRP (high-sensitivity C-reactive protein) – a blood test that measures inflammation in your blood vessels. Higher levels are linked to heart disease risk and can affect blood flow throughout the body, including sexual function.

• Lipoprotein(a) – a type of "bad" cholesterol that's largely determined by genetics. High levels significantly increase your risk of heart disease and stroke regardless of your lifestyle, which can impact blood flow and sexual health.

These aren’t routine for every guy. But in the right setting, they matter.

Not Sure How to Bring It Up?

Here’s a simple way to start:

“I’ve been feeling off – lower libido, less energy, harder time with weight – and I’d like to look at testosterone and any underlying hormonal or metabolic causes that might be playing a role.”

That’s it. You don’t need to walk in with a lab list.

You just need to show up – and speak up.

Final Thought

Labs can be helpful. But they’re not the fix.

They’re a tool to help understand what’s going on – not a scoreboard, and not a shortcut. Testosterone is one piece. 

But so are sleep, stress, metabolism, and mood.

Done well, lab work doesn’t lead to reflex prescriptions.

It leads to better conversations – and smarter conversations. 

If you found this helpful, forward it to a friend.

Chances are, someone you know has been meaning to bring this up – but didn’t know how.