TRT And Heart Health: What The Evidence Says

Written by the UPGUYS Editorial Team

Published on September 23, 2026

Concerns about testosterone and cardiovascular safety have existed for years. Earlier observational studies produced conflicting results, which made it difficult to determine whether testosterone therapy increased or decreased cardiovascular risk.

More recent randomized evidence has provided stronger reassurance, particularly the large TRAVERSE trial. In men with confirmed hypogonadism who had pre-existing cardiovascular disease or a high cardiovascular risk, testosterone therapy did not increase the rate of major adverse cardiovascular events compared with placebo.

That does not mean testosterone replacement therapy (TRT) is risk-free or appropriate for every man. For men considering testosterone replacement therapy (TRT) in Canada, treatment should be based on a proper diagnosis of testosterone deficiency, along with an individualized review of cardiovascular history, blood pressure, hematocrit and other risk factors.

Topics covered in this article:

Does TRT Increase Cardiovascular Risk?

Current randomized evidence does not show an increased rate of major cardiovascular events such as cardiovascular death, nonfatal heart attack or nonfatal stroke in appropriately selected men with hypogonadism.

The strongest evidence comes from the TRAVERSE trial, which was specifically designed to evaluate cardiovascular safety in middle-aged and older men with hypogonadism who already had cardiovascular disease or were at high cardiovascular risk.

However, cardiovascular safety does not mean zero risk.

Individual factors still matter, including:

1. Existing cardiovascular disease
2. Blood pressure
3. Hematocrit
4. History of blood clots
5. Heart rhythm problems
6. Other cardiovascular risk factors

TRT can also affect blood pressure and red blood cell production, which is why monitoring remains important even when the overall major cardiovascular-event data are reassuring.

The key point is that current evidence does not support the idea that appropriately prescribed TRT broadly increases major cardiovascular events, but treatment decisions should still be individualized.

What Did the TRAVERSE Trial Find?

The TRAVERSE trial found that testosterone therapy was not associated with a higher rate of major adverse cardiovascular events than placebo in men with hypogonadism and pre-existing or high cardiovascular risk.

TRAVERSE was a large randomized, double-blind, placebo-controlled cardiovascular safety trial involving 5,246 men between 45 and 80 years old.

Participants had:

1. Symptoms of hypogonadism
2. Two fasting testosterone measurements below 300 ng/dL
3. Pre-existing cardiovascular disease or a high risk of cardiovascular disease

Participants were assigned to either daily transdermal testosterone gel or placebo.

The primary outcome included cardiovascular death, nonfatal heart attack and nonfatal stroke.

Major adverse cardiovascular events occurred in:

1. 7.0% of the testosterone group
2. 7.3% of the placebo group

The hazard ratio was 0.96, and testosterone met the study's predefined criteria for noninferiority compared with placebo.

The mean treatment duration was approximately 22 months, while the mean follow-up period was 33 months.

These findings provide important reassurance about major cardiovascular events, but they need to be interpreted carefully.

TRAVERSE studied transdermal testosterone gel, not every available TRT formulation. It was also designed to test cardiovascular safety, not to determine whether TRT prevents heart attacks, strokes or cardiovascular disease.

In other words, the trial supports the conclusion that TRT did not increase major cardiovascular events in this specific high-risk population, but it does not establish testosterone therapy as a cardiovascular treatment.

Does TRT Cause Heart Attacks?

Current randomized evidence has not shown a significant increase in heart attacks among men with confirmed hypogonadism receiving TRT.

In TRAVERSE, nonfatal myocardial infarction was included as part of the primary cardiovascular endpoint, and the overall rate of major cardiovascular events was similar between testosterone and placebo.

Broader randomized evidence has reached a similar conclusion. A 2024 meta-analysis of 30 randomized controlled trials involving 11,502 participants found no significant difference in myocardial infarction between men receiving TRT and those receiving placebo.

This does not mean TRT prevents heart attacks or improves cardiovascular health.

The evidence is better interpreted as showing that, in appropriately selected and monitored men with hypogonadism, TRT has not been shown to significantly increase heart attack risk.

Proper diagnosis, cardiovascular assessment and ongoing monitoring still remain important parts of treatment.

Does TRT Increase Stroke Risk?

Current randomized evidence has not shown a significant increase in stroke risk with TRT in men treated for hypogonadism.

In the TRAVERSE trial, nonfatal stroke was included in the primary major adverse cardiovascular event endpoint, together with cardiovascular death and nonfatal heart attack. The overall rate of these events was similar between the testosterone and placebo groups.

Recent meta-analyses of randomized trials have also generally not found a significant increase in stroke risk with testosterone therapy.

That does not mean individual stroke risk can be ignored. Factors such as age, blood pressure, smoking, diabetes, atrial fibrillation and previous cardiovascular or cerebrovascular disease still matter when deciding whether TRT is appropriate.

The safest interpretation is that current randomized evidence is reassuring about stroke risk overall, while individual cardiovascular risk assessment remains important.

What Does “Cardiovascular Safety” Actually Mean?

Cardiovascular safety means that TRT did not increase the rate of major cardiovascular events in the population studied. It does not mean every possible cardiovascular problem is unaffected.

TRAVERSE found no increase in the primary composite of cardiovascular death, nonfatal heart attack and nonfatal stroke compared with placebo.

However, that finding should not be interpreted as meaning:

1. TRT has no cardiovascular risks at all
2. Every cardiovascular event occurs at the same rate
3. TRT prevents heart disease
4. TRT reduces heart attack or stroke risk
5. Every TRT formulation has been studied to the same degree
6. Long-term outcomes beyond the study period are fully known

The population also matters. TRAVERSE studied men aged 45 to 80 with confirmed hypogonadism and pre-existing or high cardiovascular risk who received transdermal testosterone gel.

That makes the trial highly relevant, but it does not mean every finding should automatically be applied to every patient, dose or testosterone formulation.

Cardiovascular safety should therefore be understood as reassuring evidence about major events within a defined population, not as proof that TRT is universally risk-free or cardioprotective.

Were Any Cardiovascular Problems More Common in TRAVERSE?

Yes. Some secondary events occurred more often in the testosterone group, even though the overall rate of major adverse cardiovascular events was not increased.

These included:

1. Atrial fibrillation
2. Nonfatal arrhythmias requiring intervention
3. Pulmonary embolism
4. Acute kidney injury

These findings are important because they show why the broader TRAVERSE result should not be simplified to “TRT has no cardiovascular risk.”

At the same time, these were secondary safety findings, and the trial was not designed or powered to provide definitive answers about every individual secondary event.

They should therefore be treated as signals that deserve attention rather than proof that TRT directly causes each of these conditions.

For men with a history of arrhythmias, blood clots, kidney disease or other relevant risk factors, these findings may be especially important during treatment assessment and monitoring.

Can TRT Cause Atrial Fibrillation or Arrhythmias?

TRAVERSE reported more atrial fibrillation and nonfatal arrhythmias in the testosterone group, although the broader evidence has been less consistent.

In TRAVERSE, atrial fibrillation occurred more often among men receiving testosterone than among those receiving placebo. The study also reported more nonfatal arrhythmias requiring intervention in the testosterone group.

A more recent meta-analysis also found an increased overall risk of arrhythmias with testosterone therapy, while not finding significant increases in myocardial infarction, stroke, cardiovascular mortality or all-cause mortality.

However, other analyses have not consistently shown the same increase in atrial fibrillation, so the evidence is not completely uniform.

For men with a history of atrial fibrillation or another rhythm disorder, this does not automatically rule out TRT, but it makes individual cardiovascular assessment and monitoring particularly important.

Can TRT Increase the Risk of Blood Clots?

TRT may affect blood-clot risk in some men, but the evidence is mixed and needs to be interpreted separately from the major arterial cardiovascular outcomes studied in TRAVERSE.

Testosterone therapy can increase red blood cell production and raise hematocrit. If hematocrit becomes too high, blood viscosity may increase, which is one reason regular blood-count monitoring is important during treatment.

Venous thromboembolism, including deep vein thrombosis and pulmonary embolism, is different from arterial events such as heart attack and stroke.

In the TRAVERSE trial, pulmonary embolism occurred more often in the testosterone group than in the placebo group. However, broader evidence on venous thromboembolism has not consistently shown the same level of increased risk.

Men with a history of:

1. Blood clots
2. Pulmonary embolism
3. Deep vein thrombosis
4. Known thrombophilia
5. Other major clotting risk factors

should discuss these factors with their healthcare practitioner before starting TRT.

This does not mean TRT automatically causes blood clots, but clotting history and hematocrit are important parts of treatment assessment and monitoring.

Can TRT Raise Blood Pressure?

Yes. Testosterone therapy can increase blood pressure in some men, so blood pressure monitoring remains important even when major cardiovascular-event data are reassuring.

The FDA has updated testosterone product labelling to include product-specific blood-pressure information after ambulatory blood-pressure studies showed increases across testosterone therapies.

The amount of change can vary by formulation and individual response.

That is why blood pressure should be checked before treatment and monitored during TRT, especially in men who already have hypertension or other cardiovascular risk factors.

For a more detailed explanation, read more about TRT and high blood pressure.

How Does Hematocrit Affect Heart and Vascular Risk on TRT?

TRT can increase hematocrit by stimulating red blood cell production.

Hematocrit is the percentage of blood volume made up of red blood cells. A moderate increase can occur during testosterone therapy, but excessive elevation may make the blood more viscous.

This is why CBC and hematocrit monitoring are an important part of TRT follow-up.

If hematocrit rises too much, a healthcare practitioner may consider:

1. Rechecking the result
2. Adjusting the TRT dose
3. Changing the treatment approach
4. Investigating other contributing factors
5. Temporarily holding treatment when clinically appropriate

The goal is to maintain the benefits of treatment while reducing avoidable vascular risk.

For a deeper explanation, read more about high hematocrit on TRT.

Can Men With Heart Disease Take TRT?

Some men with stable cardiovascular disease may still be considered for TRT if they have confirmed testosterone deficiency, but the decision should be individualized.

Having heart disease does not automatically mean TRT is prohibited.

In fact, the TRAVERSE trial specifically included men with pre-existing cardiovascular disease or a high cardiovascular risk, and the overall rate of major adverse cardiovascular events was similar between testosterone and placebo.

However, stable cardiovascular disease is different from a recent or unstable cardiovascular event.

Before starting TRT, a healthcare practitioner may consider:

1. The type and stability of cardiovascular disease
2. Recent heart attack or stroke
3. Blood pressure
4. Hematocrit
5. Arrhythmia history
6. Blood-clot history
7. Current cardiovascular symptoms
8. Other cardiovascular risk factors

The decision should remain practitioner-led and based on confirmed testosterone deficiency, overall cardiovascular status and the individual's treatment risks and goals.

Can You Take TRT After a Heart Attack or Stroke?

TRT is generally not started immediately after a recent heart attack or stroke.

Current Endocrine Society guidance recommends against starting testosterone therapy in men who have had a myocardial infarction or stroke within the previous six months.

After that period, the decision is more individualized. A healthcare practitioner may consider:

1. How recently the cardiovascular event occurred
2. Whether the condition is now stable
3. Current heart or neurological symptoms
4. Blood pressure
5. Hematocrit
6. Other cardiovascular risk factors
7. Whether testosterone deficiency has been properly confirmed

In some cases, input from a cardiologist or other specialist may be appropriate before treatment is started or resumed.

The six-month recommendation should not be interpreted as meaning TRT automatically becomes appropriate once six months have passed. Cardiovascular stability, confirmed hypogonadism and the individual's overall risk still need to be assessed.

Is TRT Safe After 50?

Age alone does not determine whether TRT is cardiovascularly safe.

Cardiovascular risk depends more on factors such as confirmed testosterone deficiency, existing heart disease, blood pressure, diabetes, smoking history, hematocrit and overall health than on reaching a particular age.

The TRAVERSE trial included men 45 to 80 years old, with an average age of approximately 63 years, and specifically enrolled men with pre-existing cardiovascular disease or elevated cardiovascular risk. In this population, major adverse cardiovascular events occurred at similar rates with testosterone gel and placebo.

That finding is reassuring for appropriately selected middle-aged and older men, but it does not mean TRT should be routinely used simply because testosterone tends to decline with age.

TRT should still be based on an appropriate diagnosis of testosterone deficiency and an individualized assessment of potential benefits and risks.

Does Low Testosterone Itself Affect Heart Health?

Low testosterone is associated with cardiovascular disease and several cardiovascular risk factors, but association does not prove that low testosterone directly causes heart disease.

Men with low testosterone are also more likely to have conditions such as:

1. Obesity
2. Type 2 diabetes
3. Metabolic syndrome
4. High blood pressure
5. Other chronic health conditions

These conditions can independently increase cardiovascular risk and may also contribute to lower testosterone.

This makes the relationship difficult to separate. A man may have both low testosterone and cardiovascular disease because they share underlying risk factors rather than because one directly caused the other.

For the same reason, correcting low testosterone should not automatically be expected to reduce cardiovascular risk.

Does TRT Improve Heart Health?

TRT should not be prescribed as a treatment to prevent heart attacks or improve cardiovascular health.

TRT may affect body composition, sexual symptoms and some metabolic measures in men with confirmed testosterone deficiency, but the cardiovascular safety data do not establish TRT as a cardioprotective treatment.

TRAVERSE was designed to determine whether testosterone increased major cardiovascular events compared with placebo. It showed no meaningful difference in cardiovascular death, nonfatal heart attack or nonfatal stroke, but it did not show that testosterone prevents these events.

The primary purpose of TRT remains the treatment of appropriately diagnosed testosterone deficiency.

Men who want to reduce cardiovascular risk should still focus on established measures such as blood pressure control, diabetes management, healthy weight, physical activity, smoking cessation when applicable and treatment of other cardiovascular risk factors.

What Did the FDA Change After TRAVERSE?

After reviewing TRAVERSE and other evidence, the FDA changed testosterone labelling to reflect the newer cardiovascular safety data while maintaining attention to blood pressure and other risks.

TRAVERSE found no meaningful difference in major adverse cardiovascular events between men receiving testosterone gel and those receiving placebo: 7.0% versus 7.3%. The FDA concluded that the trial did not identify a new cardiovascular safety signal or trend.

In 2025, cardiovascular-risk warning language was removed from U.S. testosterone product labelling, while blood pressure warnings were added or strengthened because ambulatory blood-pressure studies showed that testosterone products can increase blood pressure.

The FDA made further testosterone labelling updates in June 2026, including changes related to age-related hypogonadism and prostate safety information.

These changes should not be interpreted as the FDA declaring TRT universally safe. They reflect updated evidence showing that major cardiovascular events were not increased in TRAVERSE, while other risks and monitoring requirements remain important.

What Should Be Checked Before TRT If You Have Cardiovascular Risk?

Men with cardiovascular risk factors should have their overall cardiovascular health reviewed before TRT is started.

Assessment may include:

1. Blood pressure
2. Cardiovascular history
3. Current cardiovascular symptoms
4. Hematocrit and CBC
5. Lipid levels when appropriate
6. Diabetes and other metabolic risk factors
7. Smoking status
8. Current medications
9. History of blood clots or arrhythmias
10. Any recent heart attack or stroke
11. Confirmation that testosterone deficiency has been properly diagnosed

The goal is to identify factors that could affect treatment safety rather than assuming that cardiovascular risk either automatically rules TRT in or rules it out.

Current Endocrine Society guidance recommends against starting TRT in men with uncontrolled heart failure, elevated hematocrit, thrombophilia or a heart attack or stroke within the previous six months.

What Should Be Monitored During TRT?

Cardiovascular and treatment-related monitoring should continue after TRT begins.

Depending on individual risk, monitoring may include:

1. Testosterone levels and symptom response
2. Blood pressure
3. Hematocrit and CBC
4. Cardiovascular symptoms
5. Heart rhythm symptoms such as palpitations
6. Other laboratory tests based on medical history and treatment type

Men should seek medical assessment for new symptoms such as chest pain, unexplained shortness of breath, significant palpitations, leg swelling or sudden neurological symptoms.

Monitoring is important because TRT can affect blood pressure and red blood cell production even when major cardiovascular-event data are reassuring. Current guidance also recommends follow-up after treatment begins to assess response and adverse effects.

When Should You Speak to a Healthcare Provider?

Speak to a healthcare provider before starting TRT if you have known cardiovascular disease or important cardiovascular risk factors.

This is especially important if you have:

1. A previous heart attack or stroke
2. A history of atrial fibrillation or another arrhythmia
3. A history of blood clots
4. Uncontrolled high blood pressure
5. Elevated hematocrit
6. Heart failure
7. New or worsening cardiovascular symptoms

Men who develop chest pain, sudden shortness of breath, neurological symptoms or other potentially serious cardiovascular symptoms should seek prompt medical attention.

TRT should not be self-started based on symptoms or a single testosterone result. Cardiovascular history, confirmed testosterone deficiency and individual treatment risks should be assessed together before treatment is started.

Key Takeaways

1. Current randomized evidence does not show an increased rate of major adverse cardiovascular events in appropriately selected men with hypogonadism.
2. In the TRAVERSE trial, major cardiovascular events occurred in 7.0% of the testosterone group and 7.3% of the placebo group.
3. TRT should not be used as a treatment to prevent heart attacks, strokes or cardiovascular disease.
4. Some secondary findings, including more atrial fibrillation, nonfatal arrhythmias and pulmonary embolism in TRAVERSE, still deserve attention.
5. Blood pressure and hematocrit monitoring remain important during TRT.
6. Men with cardiovascular disease or significant cardiovascular risk factors need individualized assessment before treatment.
7. Age alone does not determine whether TRT is appropriate or cardiovascularly safe.

FAQ