Does TRT raise blood pressure? What the science says

Testosterone therapy offers a lifeline for vitality and strength, but concerns about cardiovascular health remain common. Here is an evidence-based breakdown of how hormone therapy affects your heart, blood vessels, and long-term health.

The relationship

For decades, the medical community operated under a cloud of uncertainty regarding testosterone replacement therapy (TRT) and cardiovascular health. The concern was intuitive: testosterone is a potent driver of physical performance, and pushing the body’s engine harder might theoretically strain the pump—the heart. However, asking “does TRT raise blood pressure” yields a complex answer that depends heavily on the individual man, his dosage, and his pre-existing health profile.

Recent high-quality evidence has shifted the narrative from fear to management. The landmark TRAVERSE trial, published in the New England Journal of Medicine in 2023, assessed over 5,000 men and found that TRT did not increase the incidence of major adverse cardiac events compared to placebo.^[1] However, clinical nuance is vital here. While the aggregate data suggests safety, individual responses vary. Some observational studies indicate that TRT can lead to modest increases in systolic blood pressure, primarily due to fluid shifts or changes in blood viscosity.

Conversely, untreated hypogonadism (low testosterone) is itself a major risk factor for hypertension. Low testosterone levels are strongly linked to metabolic syndrome, obesity, and insulin resistance—three primary drivers of high blood pressure.^[2] A 2024 study in the World Journal of Men’s Health even found that for a specific cohort of men, optimizing testosterone levels was associated with a reduction in blood pressure as metabolic health improved. This suggests a U-shaped curve: both extremely low and supra-physiological (too high) levels of testosterone can be detrimental to blood pressure, while physiological optimization often supports vascular health.

How it works

To understand the question “does TRT raise blood pressure,” we must look at the specific physiological mechanisms that testosterone influences. It is rarely a direct attack on the arteries; rather, it is a downstream effect of how the hormone changes blood composition and fluid balance.

Erythrocytosis (Thickening of the blood)

One of the most well-documented side effects of TRT is erythrocytosis. Erythrocytosis is an increase in the production of red blood cells, which carry oxygen throughout the body. Testosterone stimulates erythropoietin (EPO) in the kidneys and directly impacts bone marrow to produce more cells.^[3]

While more red blood cells can improve endurance, too many increase the viscosity (thickness) of the blood. Thicker blood flows with more resistance, forcing the heart to pump harder to push it through the vascular system. This resistance is a primary mechanical cause of elevated blood pressure in men on TRT.

Sodium and water retention

Testosterone has a mineralocorticoid effect, meaning it can influence how the kidneys handle salt and water. Initiating TRT often leads to a temporary phase of sodium retention. Where sodium goes, water follows.^[4]

This excess fluid increases total blood volume. Since the circulatory system is a closed loop, adding more volume without expanding the container (the blood vessels) inevitably raises the pressure within that system. This is often why men notice “water weight” gain or slight swelling in the ankles during the first few months of therapy.

Vascular tone and vasodilation

Interestingly, testosterone also has a direct relaxing effect on blood vessels, known as vasodilation. It acts on the smooth muscle cells lining the arteries, encouraging them to open up. This mechanism actually works against high blood pressure.

This opposing force explains why the data is mixed. In some men, the fluid retention and red blood cell increase overpower the vasodilation, causing pressure to rise. In others, particularly those with metabolic issues, the vasodilation and weight loss win out, causing pressure to drop or stay neutral.

Conditions linked to it

When asking does TRT raise blood pressure, we must consider the conditions that act as accomplices. TRT rarely raises blood pressure in isolation; it usually interacts with pre-existing conditions that men may not know they have.

Obstructive Sleep Apnea (OSA): This is the most significant confounding factor. OSA is a condition where breathing stops intermittently during sleep, causing oxygen levels to plummet and stress hormones to spike. Untreated sleep apnea is a massive driver of hypertension. Evidence suggests that TRT can worsen untreated sleep apnea, which in turn skyrockets blood pressure.^[5] Treating the apnea (often with CPAP) usually resolves the blood pressure issue even while continuing testosterone.

Secondary Polycythemia: This is the clinical term for the excessive red blood cell count mentioned earlier. If hematocrit (the percentage of blood volume made up of red blood cells) rises above 54%, the risk of clotting and hypertension increases significantly.^[6] This is dose-dependent and more common with injectable testosterone esters than with transdermal gels or creams.

Symptoms and signals

High blood pressure is famously called the “silent killer” because it often presents no obvious symptoms until damage is done. However, when related to the rapid physiological changes of TRT, certain signals may appear. If you are undergoing hormone therapy, watch for these signs:

• Chronic headaches: Specifically a dull, pounding ache at the back of the head or neck, often worse in the morning.
• Flushing: A sensation of heat or redness in the face and chest that is not related to embarrassment or exercise.
• Bounding pulse: Feeling your heart beating strongly in your neck or ears when you are trying to relax.
• Visual changes: Blurring or “spots” in your vision could indicate significant pressure spikes.
• Shortness of breath: Difficulty catching your breath during activities that used to be easy, which could signal fluid retention affecting the heart or lungs.

What to do about it

Managing cardiovascular health while on TRT is not a passive process. It requires a proactive strategy that involves precise testing, lifestyle adjustment, and protocol management.

1. Diagnostic Precision
Before assuming TRT is the cause of blood pressure issues, confirm you actually need therapy and establish a baseline. Meta analyses indicate that symptomatic men with total testosterone below 350 ng/dL (≈12 nmol/L) are most likely to benefit from TRT. If total testosterone is borderline, measure free testosterone; values below 100 pg/mL (≈10 ng/dL) support hypogonadism. In practice, use 350 ng/dL for total or 100 pg/mL for free as decision thresholds when symptoms persist.^[7] Treating men with normal levels yields high risk with low reward.

2. Protocol Adjustment
If blood pressure rises, the delivery method matters. Injectable testosterone, particularly when given in large, infrequent doses (e.g., every two weeks), creates high peaks that stimulate excessive red blood cell production. Switching to more frequent, smaller injections (micro-dosing) or moving to transdermal gels can significantly reduce hematocrit elevation and fluid retention.^[8]

3. Therapeutic Phlebotomy
If blood pressure is elevated due to high hematocrit, a therapeutic phlebotomy (blood donation) can be an immediate solution. Removing a pint of blood lowers viscosity, instantly reducing the mechanical load on the heart. This should be done under physician guidance to ensure ferritin (iron storage) levels do not crash.

Myth vs Fact

• Myth: TRT always causes heart attacks.
  
  Fact: Current large-scale data, including the TRAVERSE trial, shows no increased risk of heart events in properly monitored men compared to placebo.
• Myth: If your blood pressure rises, you must quit TRT immediately.
  
  Fact: Usually, blood pressure can be managed by adjusting the dose, changing the delivery method, or treating fluid retention, without stopping therapy entirely.
• Myth: Testosterone gels are safer for the heart than injections.
  
  Fact: Gels tend to cause less spike in red blood cell count (hematocrit) than injections, which may make them a better option for men prone to high blood pressure, but “safer” depends on the individual’s compliance and absorption.
• Myth: You only need to check testosterone levels once a year.
  
  Fact: During the first year, and whenever changing doses, blood work (including hematocrit and PSA) should be done every 3 to 6 months to catch BP-related changes early.

Bottom line

Does TRT raise blood pressure? It can, but it is not a guarantee, nor is it unmanageable. The rise in pressure is typically mechanical—driven by fluid retention or thicker blood—rather than a direct toxic effect on the heart. For men with clinically low testosterone, the cardiovascular risks of staying untreated (obesity, diabetes, metabolic syndrome) often outweigh the manageable risks of therapy. Success lies in regular monitoring, respecting physiological thresholds, and viewing TRT as one pillar of a broader health strategy rather than a magic bullet.

References

1. Lincoff AM, Bhasin S, Flevaris P, et al. Cardiovascular Safety of Testosterone-Replacement Therapy. The New England journal of medicine. 2023;389:107-117. PMID: 37326322
2. Kloner RA, Carson C, Dobs A, et al. Testosterone and Cardiovascular Disease. Journal of the American College of Cardiology. 2016;67:545-57. PMID: 26846952
3. Bachman E, Travison TG, Basaria S, et al. Testosterone induces erythrocytosis via increased erythropoietin and suppressed hepcidin: evidence for a new erythropoietin/hemoglobin set point. The journals of gerontology. Series A, Biological sciences and medical sciences. 2014;69:725-35. PMID: 24158761
4. Svartberg J, von Mühlen D, Schirmer H, et al. Association of endogenous testosterone with blood pressure and left ventricular mass in men. The Tromsø Study. European journal of endocrinology. 2004;150:65-71. PMID: 14713281
5. Killick R, Wang D, Hoyos CM, et al. The effects of testosterone on ventilatory responses in men with obstructive sleep apnea: a randomised, placebo-controlled trial. Journal of sleep research. 2013;22:331-6. PMID: 23331844
6. Fernández-Balsells MM, Murad MH, Lane M, et al. Clinical review 1: Adverse effects of testosterone therapy in adult men: a systematic review and meta-analysis. The Journal of clinical endocrinology and metabolism. 2010;95:2560-75. PMID: 20525906
7. Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and Management of Testosterone Deficiency: AUA Guideline. The Journal of urology. 2018;200:423-432. PMID: 29601923
8. Ohlander SJ, Varghese B, Pastuszak AW. Erythrocytosis Following Testosterone Therapy. Sexual medicine reviews. 2018;6:77-85. PMID: 28526632