Systemic Inflammation and TRT: What the Evidence Actually Shows

By Dr. Farhan Abdullah, DO | Medical Director, Magnolia Functional Wellness | Southlake, TX

A patient sat down in my office last month with a printout of his labs and a question I hear more often than you'd think. "My hs-CRP is up, my testosterone is low, and I read that low T causes inflammation. So if I fix the testosterone, does the inflammation go away?"

It's a fair question. It's also one where the honest answer is messier than most online articles admit. I'm Dr. Farhan Abdullah, an internal medicine physician, and at Magnolia Functional Wellness in Southlake I spend a lot of time sorting out which claims about testosterone hold up and which ones got ahead of the data. The inflammation story is a good example, because part of it is well supported and part of it is still unsettled.

Why Inflammation Matters in the First Place

Acute inflammation is your body doing its job. You sprain an ankle, it swells, immune cells rush in, and the tissue heals. Nobody wants to turn that off.

The trouble is the slow, low-grade version. Chronic systemic inflammation hums along in the background for years, often with no obvious symptom, and it's tied to insulin resistance, atherosclerosis, fatty liver, joint pain, and the gradual loss of muscle. In my hospital work I see the end of that road: patients in their sixties and seventies with three or four conditions that all seem to feed one another. The question I keep asking myself is how many of those patients had a quiet inflammatory problem a decade earlier that nobody measured.

So when a man in his forties walks in tired, carrying extra weight around the middle, with low testosterone on paper, I'm not only thinking about his energy. I'm thinking about the whole metabolic picture.

What Testosterone Actually Does to the Immune System

Testosterone isn't just a sex hormone. Immune cells carry androgen receptors, which means testosterone talks to them directly. In lab and clinical studies, low testosterone tends to travel with higher levels of pro-inflammatory signaling molecules like interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha). Those are the same messengers that get elevated when visceral fat is busy pumping out inflammatory signals.

A 2018 review in the Asian Journal of Andrology on randomized trials of testosterone and the cardiovascular system summarized the mechanistic evidence this way: testosterone replacement can suppress circulating pro-inflammatory cytokines and stimulate production of interleukin-10, a molecule with anti-inflammatory and anti-atherogenic effects, in men with cardiovascular disease. That's a real signal, and it's consistent with what I'd expect biologically.

Now here's the part the marketing copy tends to skip. The same review noted that no effect on C-reactive protein had been detected across the trials it examined. Read that twice if you need to. The cytokines moved. The most commonly ordered inflammation marker in your doctor's office didn't reliably follow.

What the Broader Evidence Shows

A 2025 systematic review published in Cureus pulled together 25 studies on testosterone replacement in hypogonadal men, looking at lipids, inflammatory markers, and vascular function. The authors reported decreases in IL-6 and TNF-alpha, along with improved endothelial-dependent vasodilation, meaning the lining of the blood vessels relaxed and responded more normally. They described benefits as most evident at physiological dosing.

They were also careful about the limits. The included studies varied a lot in formulation, dose, treatment duration, and the type of patients enrolled, so the authors synthesized the results narratively instead of pooling them into a single number. And they called for higher-quality, longer-duration trials to firm up the conclusions.

So where does that leave us? Somewhere in the middle, which is where a lot of good medicine lives. There's a reasonable body of evidence that testosterone therapy in men with true deficiency lowers some inflammatory cytokines. There isn't strong evidence that it's a dependable way to bring down an elevated hs-CRP, and nobody has shown that treating testosterone is a substitute for treating the actual sources of inflammation.

The Part Most Men Overlook: Where the Inflammation Comes From

When a man's hs-CRP is high, testosterone is rarely the whole story. Visceral fat is a major contributor. So is poor sleep, and sleep apnea in particular, which also drags testosterone down. Add chronic stress, heavy alcohol use, an untreated gut or dental problem, and a diet built around ultra-processed food, and you've got plenty of fuel without any help from your hormones.

This is where my functional medicine training shapes how I work. I'd rather find the driver than chase the number. A man who starts testosterone therapy and changes nothing else may see his energy and body composition improve, but if the belly fat, the snoring, and the six-hour nights stay put, I wouldn't be surprised if his inflammatory markers barely budge.

The relationship also runs in both directions. Inflammation can suppress the signaling that tells the testes to make testosterone, and excess fat tissue converts testosterone into estrogen. Low testosterone can encourage fat gain, and fat gain can push testosterone lower. It's a loop. Sometimes the best first move is breaking the loop from another angle entirely, through weight loss, sleep treatment, or resistance training, and then rechecking labs before deciding whether testosterone therapy is still needed.

Reading Your hs-CRP Without Panicking

Since so many men arrive holding that one number, it's worth saying what it can and can't tell you. High-sensitivity C-reactive protein is a liver-made protein that rises when inflammatory signaling is turned up. It's cheap, it's widely available, and it's a reasonable screening tool. It's also a blunt one.

A head cold last week can push it up. So can a hard leg workout, a dental infection, or a bad flare of seasonal allergies. One reading tells me very little. Two or three readings taken weeks apart, when you're feeling well, tell me much more. I generally like to see a persistent elevation before drawing conclusions, and then I want to know what's behind it. Is waist circumference creeping up? Are triglycerides high and HDL low? Does his partner say he stops breathing at night? Those details matter more than any single lab value.

There's another wrinkle. Because testosterone therapy doesn't reliably change CRP in the trials, a flat CRP after a few months doesn't mean the treatment failed, and a lower one doesn't prove it worked through an anti-inflammatory effect. I treat it as one data point in a larger dashboard, along with how you feel, how you're sleeping, and what your body composition is doing.

Five Things That Lower Inflammation Whether or Not You Take Testosterone

I tell patients that hormone therapy should ride on top of a solid foundation, not stand in for one. These are the levers I see move inflammatory markers most consistently in practice.

• Losing visceral fat. Even a modest reduction in waist size tends to cool the inflammatory signaling that belly fat produces.
• Resistance training two or three times a week, which builds muscle that acts as a metabolic buffer.
• Seven to eight hours of sleep, and a proper sleep study if you snore or wake unrefreshed.
• A diet built around vegetables, fish, olive oil, and adequate protein instead of refined carbohydrates and processed meats.
• Cutting back on alcohol, which irritates the gut lining and adds to the inflammatory load more than most people expect.

None of that sounds exciting. But I'd take a patient who does those five things and starts testosterone over one who only does the latter, every time. In my experience the first patient feels better faster and ends up needing less of everything.

How We Approach It at Magnolia

If you come to see me with fatigue, low drive, and suspected low testosterone, here's roughly what happens. We confirm the diagnosis with morning labs on more than one occasion, because a single low reading can be a bad night's sleep or an illness. We look at total and free testosterone, SHBG, estradiol, hematocrit, PSA when appropriate, a metabolic panel, lipids, A1c, and hs-CRP. I like having that inflammation baseline even though I wouldn't promise it will move.

If you qualify for treatment, we talk through the risks and benefits honestly, including the ones that need monitoring, such as red blood cell count and prostate health. You can read more about how we run that process on our testosterone replacement therapy page, and our guide on what men over 30 need to know before starting covers the questions I get most in the first visit.

Then we recheck. If hs-CRP is still elevated after several months of well-managed therapy, I don't shrug and call it fine. I go looking for the other sources: sleep, weight, diet, stress, hidden infections. That's the difference between treating a hormone level and treating a person.

I also spend real time on expectations. Men often hope a single prescription will fix the fatigue, the weight, the brain fog, and the aching joints all at once. Testosterone can help with several of those when the deficiency is real. It won't erase a decade of poor sleep or a diet that runs on drive-through lunches, and I'd rather say that in the first visit than let you discover it in month four.

And yes, the lifestyle piece matters even more in Texas summers, when it's tempting to skip outdoor workouts from June through September. Lifting indoors twice a week does real work on both testosterone and inflammation, and it costs nothing but the drive to the gym.

What to Take Away From All This

Testosterone has real biological effects on the immune system, and in men who are truly deficient, replacing it appears to shift some inflammatory cytokines in a favorable direction. That's encouraging. It isn't a guarantee, and it isn't a reason to start therapy on its own if your testosterone is normal.

If you're in Southlake or anywhere around DFW and you've been told your inflammation is high, your testosterone is low, or both, bring the actual numbers to an appointment and let's look at the whole picture together. At Magnolia Functional Wellness, the goal is to find what's driving your symptoms, not to sell you a single answer. Sometimes the answer includes testosterone. Sometimes it starts somewhere else.

This article is for educational purposes and isn't a substitute for individualized medical advice. Testosterone therapy isn't appropriate for everyone and requires a proper evaluation and ongoing monitoring.