TRT and Blood Pressure: What the Research Actually Shows

The Question Every Man Asks Before Starting TRT

You have been reading about whether to start testosterone replacement therapy. Your levels are low. Your symptoms are real. You are ready to do something about it. And then you see it — a warning about blood pressure. Maybe it was on the prescribing information. Maybe it came up in a forum. Maybe your doctor mentioned it as a reason to be cautious.

Suddenly the decision feels less straightforward. You already know the broader safety profile of TRT, but blood pressure hits different. It is not some abstract lab marker. It is the number your doctor checks every visit. The one that quietly drives heart attacks and strokes. The silent killer.

So does TRT actually raise blood pressure? The answer is more nuanced than either the fearmongers or the enthusiasts would have you believe. And in February 2025, the FDA issued a major labeling update for all testosterone products that reframed the entire conversation. Here is what the research actually shows — not simplified, not cherry-picked, but the full picture that lets you make an informed decision.

What the FDA Said in February 2025

On February 28, 2025, the FDA issued class-wide labeling changes for every testosterone product on the market. This was one of the most significant regulatory updates in the history of TRT, and it said two important things simultaneously.

The good news: The FDA removed language from the Boxed Warning related to increased risk of adverse cardiovascular outcomes. For years, testosterone products carried a black box warning — the most serious type of warning the FDA can issue — suggesting that TRT increased the risk of heart attacks and strokes. That language is now gone, based on evidence from the landmark TRAVERSE trial showing no increased cardiovascular risk.

The caveat: At the same time, the FDA added new warnings about increased blood pressure for all testosterone products. This was based on postmarket ambulatory blood pressure monitoring (ABPM) studies that confirmed testosterone products can raise blood pressure.

In other words, the FDA is now saying: TRT does not increase your risk of having a heart attack or stroke, but it can raise your blood pressure, and that needs to be monitored.

Those two statements are not contradictory. They reflect what the actual data shows — and they underline why proper monitoring while on TRT matters so much.

The TRAVERSE Trial: The Study That Changed Everything

The Testosterone Replacement Therapy for Assessment of Long-term Vascular Events and Efficacy Response in Hypogonadal Men — better known as the TRAVERSE trial — is the gold standard study on testosterone and cardiovascular safety. Here is why it matters.

Study Design

TRAVERSE enrolled over 5,200 men between the ages of 45 and 80. Every participant had diagnosed hypogonadism (low testosterone) and pre-existing cardiovascular risk factors or established cardiovascular disease. This was not a study of healthy young men. These were exactly the patients doctors worry about most when prescribing TRT.

The trial was randomized, double-blind, and placebo-controlled — the highest quality of clinical evidence. Men were followed for a mean of 33 months, with some followed for up to five years.

The Results

The primary outcome was a composite of cardiovascular death, nonfatal heart attack, and nonfatal stroke. The rate was approximately 7 percent in both the testosterone group and the placebo group. There was no statistically significant difference.

Additionally, the trial found:

• No increased risk of cardiovascular death
• No increased risk of nonfatal heart attack
• No increased risk of nonfatal stroke
• No increased risk of prostate cancer
• No worsening of lower urinary tract symptoms or BPH

This was the study the FDA used as the primary basis for removing the cardiovascular boxed warning. For men considering TRT who have been scared off by vague fears about heart health, TRAVERSE provides powerful reassurance — especially given that the study population was specifically selected for high cardiovascular risk.

How Testosterone Actually Affects Blood Pressure

Understanding the mechanism helps you manage the risk. Testosterone influences blood pressure through several pathways — some that push it up and some that pull it down. The net effect depends on your individual physiology, your starting blood pressure, and how well your treatment is monitored.

Mechanisms That Can Raise Blood Pressure

• Sodium and water retention: Testosterone promotes sodium reabsorption in the kidneys. More sodium means more water retention, which increases blood volume and raises blood pressure. This is the primary mechanism the FDA cited in its labeling update.
• Increased red blood cell production: Testosterone stimulates erythropoiesis — the production of red blood cells. While this can improve oxygen delivery and energy, too many red blood cells thicken the blood, increasing hematocrit levels and raising blood pressure. This is one of the most important markers to monitor on TRT.
• Sympathetic nervous system activation: In some individuals, testosterone may increase sympathetic nerve activity, which can elevate heart rate and blood pressure, particularly in the early weeks of treatment.

Mechanisms That Can Lower Blood Pressure

• Reduced visceral fat: Testosterone therapy consistently reduces visceral abdominal fat — the deep belly fat that actively contributes to hypertension through inflammatory signaling and insulin resistance. Less visceral fat means lower blood pressure. (Why visceral fat matters.)
• Improved insulin sensitivity: Low testosterone is strongly associated with insulin resistance and metabolic syndrome, both of which drive hypertension. Restoring testosterone to normal levels improves insulin sensitivity, which can lower blood pressure over time. (Testosterone and metabolic health.)
• Vasodilation: Testosterone has direct vasodilatory effects — it relaxes blood vessel walls, which reduces vascular resistance and lowers blood pressure. Studies show testosterone induces endothelium-independent relaxation of coronary arteries and peripheral vessels.
• Reduced inflammation: Chronic low-grade inflammation drives arterial stiffness and hypertension. Testosterone replacement reduces inflammatory markers like C-reactive protein and IL-6, which can improve vascular health over time.

This is why the blood pressure picture with TRT is complicated. In the short term, sodium retention and increased red blood cell production can push blood pressure up. In the long term, body composition improvements, better insulin sensitivity, and reduced inflammation can push it down. The net effect varies by individual — which is exactly why monitoring matters.

What the Actual Blood Pressure Changes Look Like

When people hear "TRT raises blood pressure," they often imagine dramatic spikes that put you in hypertensive crisis territory. The reality is far more modest — but still clinically relevant and worth monitoring.

Study	TRT Type	Systolic BP Change	Diastolic BP Change	Key Finding
TRAVERSE Trial (2023)	Testosterone gel	Not significantly increased at 6 months	Not significantly increased	No significant BP rise with gel
FDA ABPM Studies (2025)	Various (class-wide)	Modest increases detected	Modest increases detected	24-hour monitoring detected increases missed by office readings
STRIDE Study (2022)	Testosterone undecanoate (IM)	No significant change	No significant change	No BP increase in hypogonadal men with T2D
Traish et al. Registry (2024)	Testosterone undecanoate (IM)	Significant decrease	Significant decrease	Long-term TRT lowered BP over 8+ years

The pattern across studies is consistent: most men on properly dosed, well-monitored TRT do not experience dangerous blood pressure elevations. Some experience modest, manageable increases — particularly in the first few months. And long-term data actually suggests TRT may lower blood pressure over time, likely through improvements in body composition and metabolic health.

What Long-Term Data Shows

Some of the most reassuring data on TRT and blood pressure comes from long-term registry studies that follow men on testosterone therapy for years, not months.

A 2024 study published in Andrologia analyzed a registry of hypogonadal men receiving testosterone undecanoate injections over periods of up to eight years. The findings were striking:

• TRT was associated with significant reductions in systolic blood pressure, diastolic blood pressure, and pulse pressure
• These reductions occurred regardless of whether men were also taking antihypertensive medication
• Men with higher baseline blood pressure saw the largest reductions
• In the untreated comparison group, blood pressure significantly increased over the same period
• Only 1.3 percent of treated men showed an increase in systolic blood pressure at final assessment

This suggests that the long-term metabolic benefits of testosterone replacement — reduced visceral fat, improved insulin sensitivity, lower inflammation — outweigh any short-term sodium retention effects. It also raises an important counterpoint: untreated hypogonadism may itself be a risk factor for worsening blood pressure.

Low testosterone is associated with obesity, metabolic syndrome, type 2 diabetes, and systemic inflammation — all of which contribute to hypertension. Leaving low testosterone untreated does not eliminate blood pressure risk. It may actually make it worse.

Does the Route of Administration Matter?

Yes — and this is an underappreciated part of the TRT safety conversation. Not all testosterone delivery methods have the same risk profile.

Administration Route	Blood Pressure Impact	Cardiovascular Risk	Notes
Intramuscular injection	Minimal to neutral long-term	No significant increase (may decrease)	Most studied, most consistent safety data
Transdermal (gel/patch)	Modest increases detected in ABPM studies	No significant increase	Steadier hormone levels, less peak-and-trough
Oral testosterone	More pronounced increases	Significantly increased in meta-analyses	First-pass liver metabolism may drive higher risk
Subcutaneous injection	Limited data, likely similar to IM	Limited long-term data	Growing in popularity for self-administration

A meta-analysis published in the Journal of Sexual Medicine found that oral testosterone produced a statistically significant increase in cardiovascular events (relative risk 2.20), while intramuscular testosterone showed no significant change — and the point estimate actually trended toward reduced risk. Transdermal testosterone fell in between.

The likely explanation is that oral testosterone undergoes first-pass metabolism in the liver, which can alter lipid profiles and clotting factors in ways that injected or transdermal testosterone does not. This is why most modern TRT protocols — including those used by telehealth platforms like Heyday — use injectable testosterone cypionate rather than oral formulations.

How to Monitor Blood Pressure on TRT

Whether TRT raises your blood pressure by a few points, lowers it over time, or has no effect at all depends on factors specific to you. That is why monitoring — not avoiding — is the right approach. Here is what a responsible monitoring protocol looks like.

Before Starting TRT

• Get a baseline: Know your blood pressure before you begin. Take readings at home over several days at the same time each morning — not just one reading at a doctor's office
• Check your hematocrit: If your hematocrit is already elevated (above 50 percent), you need to address that before starting TRT, as it will likely increase further
• Review your complete blood work panel: Metabolic markers, lipids, kidney function, and inflammatory markers all provide context for interpreting future blood pressure changes
• Assess your current risk factors: Family history of hypertension, existing metabolic conditions, smoking status, alcohol intake, and chronic stress all influence how TRT will affect your blood pressure

During the First Three Months

• Check blood pressure weekly: Use a validated home blood pressure monitor. Take two readings one minute apart, first thing in the morning before caffeine or exercise. Log both numbers.
• Watch for sodium retention symptoms: Ankle swelling, tight rings, puffiness in the face, sudden weight gain (2 or more pounds in a week without dietary change) — these are signs of fluid retention that may precede a blood pressure increase
• Get blood work at 6 to 8 weeks: Check hematocrit, hemoglobin, kidney function, and estradiol alongside testosterone levels

Ongoing Monitoring

• Blood pressure check at least monthly: Once stable, monthly home checks are sufficient for most men. Any reading consistently above 140/90 should be discussed with your provider.
• Blood work every 3 to 6 months: Hematocrit is particularly important to track, as elevated hematocrit independently raises blood pressure
• Annual comprehensive panel: Including lipids, metabolic markers, and inflammatory markers to track the long-term metabolic improvements that often accompany well-managed TRT

What to Do if Your Blood Pressure Goes Up on TRT

If you start TRT and notice your blood pressure climbing, the answer is not to panic or immediately stop treatment. There are specific, evidence-based steps to address it.

Step 1: Rule Out Confounders

Before assuming TRT is the cause, check whether something else changed around the same time. Increased salt intake, reduced exercise, worse sleep, higher stress, increased alcohol consumption, or weight gain from causes unrelated to TRT can all raise blood pressure. Starting TRT sometimes coincides with lifestyle changes (positive or negative) that independently affect blood pressure.

Step 2: Check Your Hematocrit

Elevated hematocrit is one of the most common causes of blood pressure increases on TRT — and it is directly treatable. If your hematocrit rises above 52 to 54 percent, blood viscosity increases enough to raise blood pressure. Solutions include dose adjustment, increased hydration, therapeutic phlebotomy (blood donation), or splitting doses for more stable levels.

Step 3: Address Sodium and Water Retention

• Reduce dietary sodium to under 2,300 mg per day (ideally under 1,500 mg if blood pressure is elevated)
• Increase potassium-rich foods — bananas, sweet potatoes, leafy greens, avocados — which counterbalance sodium's blood pressure effects
• Drink adequate water (paradoxically, dehydration can worsen sodium retention)
• Moderate caffeine — excess caffeine amplifies both sodium retention and sympathetic nervous system activation

Step 4: Optimize Lifestyle Factors

• Exercise: Regular aerobic exercise (150 minutes per week of moderate intensity) is one of the most effective nonpharmacological interventions for blood pressure. Resistance training also helps long-term.
• Sleep: Poor sleep independently raises blood pressure. If you are not sleeping well on TRT, address it — this is a common issue with solutions. (TRT and sleep.)
• Stress management: Chronic cortisol elevation raises blood pressure through increased vascular resistance. Addressing stress is not optional for blood pressure management.
• Weight management: Every 10 pounds of fat lost reduces systolic blood pressure by approximately 5 to 20 mmHg. TRT itself often helps with this over time.

Step 5: Talk to Your Provider About Dose Adjustment

If blood pressure remains elevated after addressing lifestyle factors and hematocrit, your TRT dose may need adjustment. Higher doses produce more sodium retention and higher hematocrit. Finding the dose that optimizes your testosterone levels while keeping blood pressure in range is the clinical sweet spot — and it requires regular blood work and provider communication.

Step 6: Consider Antihypertensive Support if Needed

For men with pre-existing hypertension or persistent blood pressure elevation on TRT, antihypertensive medication may be appropriate alongside testosterone therapy. The long-term registry data actually shows that men on both TRT and antihypertensive medication experienced larger blood pressure reductions than those on either alone. TRT does not interfere with blood pressure medications — they work synergistically.

The Bottom Line

TRT and blood pressure is not a simple yes-or-no question. The research — including the largest clinical trial ever conducted on testosterone therapy — shows that TRT does not increase the risk of heart attacks, strokes, or cardiovascular death. The FDA recognized this in its historic February 2025 labeling update by removing the cardiovascular boxed warning.

At the same time, testosterone products can cause modest blood pressure increases, primarily through sodium retention and increased red blood cell production. The FDA acknowledged this too, adding blood pressure warnings to all testosterone labels.

But here is what often gets lost in the headlines: long-term data shows that well-managed TRT can actually lower blood pressure over time through improvements in body composition, insulin sensitivity, and inflammation. And untreated low testosterone — with its associated visceral fat accumulation, metabolic dysfunction, and chronic inflammation — is itself a risk factor for hypertension.

The answer is not to avoid TRT because of blood pressure concerns. The answer is to monitor it properly, optimize the lifestyle factors that influence it, and work with a provider who tracks your numbers and adjusts your protocol when needed. That is what responsible testosterone therapy looks like.