Does TRT Increase Heart Attack or Stroke Risk? What the TRAVERSE Study Found

For years, one of the biggest questions surrounding testosterone replacement therapy has been whether TRT increases the risk of heart attack, stroke, or other serious cardiovascular events.

Earlier research produced conflicting findings, leaving many men uncertain about the cardiovascular safety of testosterone treatment.

The TRAVERSE testosterone study was designed specifically to address that concern.

Published in 2023, TRAVERSE was a large randomized cardiovascular safety trial involving more than 5,000 men with confirmed testosterone deficiency who either had cardiovascular disease or were considered at increased cardiovascular risk.

The study’s primary finding was important:

Testosterone therapy did not increase the overall rate of cardiovascular death, nonfatal heart attack, or nonfatal stroke compared with placebo.

That is reassuring, but it does not mean TRT is risk-free or appropriate for every man.

At RenewFX Health & Wellness, testosterone therapy is evaluated within the broader context of the patient’s health. Our approach is led by an experienced, board-certified physician specializing in hormone therapy and integrative medicine, with an emphasis on comprehensive, personalized care rather than isolated hormone numbers.

Here is what men should understand about the TRAVERSE study and what its findings mean for testosterone therapy today.

What Was the TRAVERSE Testosterone Study?

TRAVERSE stands for:

Testosterone Replacement Therapy for Assessment of Long-Term Vascular Events and Efficacy Response in Hypogonadal Men.

The study was designed to answer a specific question:

Does appropriately prescribed testosterone replacement therapy increase cardiovascular risk in men with confirmed testosterone deficiency?

Researchers enrolled more than 5,000 men who had:

• Symptoms consistent with testosterone deficiency
• Repeated low testosterone measurements
• Existing cardiovascular disease or increased cardiovascular risk

Participants were randomly assigned to receive either testosterone therapy or placebo.

This randomized, placebo-controlled design made TRAVERSE considerably stronger than many earlier observational studies that had raised concerns about TRT and cardiovascular disease.

Learn more about Testosterone Replacement Therapy at RenewFX.

Who Participated in the TRAVERSE Trial?

TRAVERSE included middle-aged and older men with hypogonadism who were already considered at elevated cardiovascular risk.

Many participants had health conditions frequently seen in men considering TRT, including:

• Obesity
• Diabetes
• Hypertension
• Metabolic disease
• Cardiovascular disease
• Other cardiovascular risk factors

That makes the findings particularly relevant to real-world testosterone treatment.

How Low Was Testosterone in the Study?

Participants had documented testosterone deficiency rather than simply wanting higher testosterone levels.

The study required repeated low testosterone measurements along with symptoms consistent with hypogonadism.

That distinction matters.

TRAVERSE studied medical testosterone replacement therapy.

It did not study:

• Bodybuilding doses
• Steroid cycles
• Testosterone stacking
• Athletic performance enhancement
• Intentionally supraphysiologic testosterone levels

The findings therefore should not be applied to high-dose anabolic steroid use.

What Type of Testosterone Was Used?

Participants received prescription transdermal testosterone gel.

Doses were adjusted to maintain testosterone within a designated physiological range.

That is important because the study evaluated medically supervised testosterone replacement—not treatment intended to maximize testosterone levels.

The clinical concept was straightforward:

Correct the deficiency → maintain an appropriate testosterone range → monitor the patient

That is very different from attempting to produce the highest possible testosterone level.

What Was the Main Cardiovascular Finding?

The primary outcome examined major adverse cardiovascular events, commonly called MACE.

These included:

• Cardiovascular death
• Nonfatal heart attack
• Nonfatal stroke

Major cardiovascular events occurred at very similar rates in the testosterone and placebo groups.

The trial demonstrated that testosterone therapy was not associated with a higher overall rate of these major cardiovascular outcomes in the population studied.

In practical terms:

TRT did not increase the overall rate of cardiovascular death, heart attack, or stroke compared with placebo.

Did Testosterone Increase Heart Attack Risk?

The TRAVERSE study did not show an increased overall rate of heart attack among men receiving testosterone.

That was important because heart attack risk had been one of the main concerns surrounding TRT.

However, this does not mean a man receiving testosterone cannot have a heart attack.

Cardiovascular risk still depends on factors such as:

• High blood pressure
• Diabetes
• Smoking
• Obesity
• Cholesterol
• Family history
• Physical inactivity
• Sleep apnea
• Existing heart disease

TRT does not replace appropriate cardiovascular risk management.

Did Testosterone Increase Stroke Risk?

The study also did not show a meaningful increase in the overall rate of nonfatal stroke among testosterone-treated men compared with placebo.

Again, that is reassuring.

But stroke risk remains individualized.

Factors such as:

• Hypertension
• Diabetes
• Smoking
• Atrial fibrillation
• Previous stroke
• Vascular disease

still matter.

Testosterone therapy should be considered within the broader medical picture.

What About Cardiovascular Death?

Cardiovascular death was included as part of the trial’s primary outcome.

The combined rate of cardiovascular death, nonfatal heart attack, and nonfatal stroke was similar between the testosterone and placebo groups.

That was the central cardiovascular safety finding of TRAVERSE.

For a broader discussion of testosterone and cardiovascular health, read Testosterone Therapy and Cardiovascular Health: What the Research Shows.

Does TRAVERSE Prove TRT Is Completely Safe?

No.

This is one of the most important conclusions patients should understand.

TRAVERSE provided reassuring evidence regarding major cardiovascular events, but testosterone therapy can still affect:

• Hematocrit
• Blood pressure
• Red blood cell production
• Fluid balance
• Fertility
• Sleep apnea
• Hormonal balance
• Heart rhythm in some patients

The correct takeaway is not:

“TRT has no risks.”

It is:

“Appropriately prescribed TRT did not increase major cardiovascular events in the men studied, but treatment still requires careful patient selection and ongoing monitoring.”

For more information, read Questions About Testosterone Replacement Therapy.

What Did TRAVERSE Find About Atrial Fibrillation?

The study observed more cases of atrial fibrillation among men receiving testosterone than among those receiving placebo.

Atrial fibrillation, or AFib, is an abnormal heart rhythm involving the upper chambers of the heart.

Possible symptoms include:

• Palpitations
• Rapid heartbeat
• Irregular heartbeat
• Shortness of breath
• Fatigue
• Lightheadedness

The finding does not mean TRT causes AFib in every patient.

But it does reinforce the importance of reviewing heart-rhythm history before and during treatment.

What Did the Study Find About Pulmonary Embolism?

Pulmonary embolism occurred somewhat more frequently in the testosterone group.

A pulmonary embolism occurs when a blood clot travels to the lungs.

Men with a history of:

• Deep-vein thrombosis
• Pulmonary embolism
• Known clotting disorders
• Thrombophilia

should discuss that history with their physician before beginning testosterone therapy.

What About Kidney Problems?

The study also observed more cases of acute kidney injury among men receiving testosterone.

That does not mean testosterone routinely damages the kidneys.

But it is another reminder that TRT should be prescribed within the context of the patient’s overall health.

Patients with kidney disease or significant chronic illness may require more individualized monitoring.

Does Testosterone Raise Blood Pressure?

It can.

Testosterone may increase blood pressure in some patients.

The degree of change may depend on factors such as:

• Dose
• Testosterone formulation
• Baseline blood pressure
• Body weight
• Kidney function
• Fluid balance
• Other medications
• Cardiovascular health

Blood pressure should therefore be evaluated before treatment and monitored over time.

Why Does Hematocrit Matter During TRT?

Testosterone stimulates red blood cell production.

TRT can therefore increase:

• Red blood cell count
• Hemoglobin
• Hematocrit

This is a well-recognized physiological effect.

If hematocrit becomes excessively elevated, blood becomes more concentrated.

Potential concerns may include:

• Increased blood viscosity
• Headaches
• Flushing
• Higher blood pressure
• Greater concern for clotting in susceptible patients

That is why CBC and hematocrit monitoring remain important even after the reassuring TRAVERSE results.

Does High Hematocrit Mean TRT Must Be Stopped?

Not always.

When hematocrit rises, the physician should determine why.

Potential contributing factors can include:

• Testosterone dose
• Treatment frequency
• Testosterone formulation
• Sleep apnea
• Smoking
• Dehydration
• Altitude
• Other health conditions

Treatment may sometimes be adjusted rather than automatically discontinued.

The important point is that elevated hematocrit should not be ignored.

What Role Does Sleep Apnea Play?

Sleep apnea is particularly important in men considering TRT.

Untreated sleep apnea can contribute to:

• Fatigue
• Low testosterone
• Elevated blood pressure
• Higher hematocrit
• Cardiovascular disease
• Heart-rhythm abnormalities

A man with low testosterone symptoms who also has loud snoring, witnessed breathing pauses, daytime sleepiness, or frequent nighttime waking may need additional evaluation.

This is one reason a broader medical evaluation can be more useful than focusing on testosterone alone.

What Does Obesity Have to Do With Testosterone and Heart Risk?

Obesity is closely connected to both testosterone deficiency and cardiovascular disease.

Excess body fat can contribute to:

• Lower testosterone
• Insulin resistance
• Type 2 diabetes
• High blood pressure
• Sleep apnea
• Abnormal cholesterol
• Chronic inflammation

Weight reduction may sometimes improve endogenous testosterone production while also reducing cardiovascular risk.

This is why metabolic health and body composition can be important parts of a testosterone evaluation.

What About Diabetes?

Men with type 2 diabetes have higher rates of both testosterone deficiency and cardiovascular disease.

A man with diabetes who is considering TRT may require careful assessment of:

• Blood glucose
• Hemoglobin A1c
• Blood pressure
• Kidney function
• Weight
• Cardiovascular history
• Testosterone response

TRT may be appropriate when true testosterone deficiency is present, but it does not replace diabetes treatment.

Does TRT Improve Cardiovascular Health?

TRT should not be prescribed as a treatment for heart disease.

Some men with testosterone deficiency may experience improvements in:

• Lean muscle mass
• Body composition
• Energy
• Exercise capacity
• Overall vitality

These changes may support broader health goals.

But testosterone should not replace:

• Blood-pressure control
• Cholesterol management
• Diabetes treatment
• Exercise
• Weight management
• Smoking cessation
• Appropriate cardiovascular medications
• Medical follow-up

The reason to prescribe TRT should be the appropriate treatment of testosterone deficiency.

What Did TRAVERSE Change About Testosterone Therapy?

TRAVERSE significantly changed the cardiovascular conversation surrounding testosterone replacement therapy.

For years, men heard broad warnings that testosterone might increase the risk of heart attack or stroke.

The study provided stronger evidence that appropriately prescribed TRT does not appear to increase the overall rate of major cardiovascular events in men with confirmed testosterone deficiency and elevated cardiovascular risk.

At the same time, the study reinforced the importance of:

• Blood pressure
• Hematocrit
• Clotting history
• Heart rhythm
• Kidney health
• Overall cardiovascular risk

The modern understanding of TRT safety is therefore more nuanced than either:

“Testosterone is dangerous.”

or

“Testosterone is completely safe.”

Does the Study Apply to Testosterone Injections?

TRAVERSE specifically studied testosterone gel.

That means its strongest conclusions apply to treatment resembling the study protocol.

Injectable testosterone can produce different patterns of:

• Peak testosterone
• Trough testosterone
• Hematocrit response
• Estradiol response
• Symptoms

The study nevertheless provides important information about testosterone replacement therapy while reinforcing that formulation, dosing, and monitoring matter.

Does TRAVERSE Apply to High-Dose Testosterone?

No.

This distinction is critical.

TRAVERSE studied medically supervised testosterone replacement intended to restore testosterone to an appropriate physiological range.

It did not evaluate:

• Steroid cycles
• Bodybuilding doses
• Testosterone stacking
• Supraphysiologic testosterone exposure
• Performance-enhancing use

The findings should not be used to claim that unlimited testosterone exposure is safe.

Does More Testosterone Provide More Benefit?

Not necessarily.

The goal of TRT is not to achieve the highest possible testosterone level.

Excessive dosing may increase the likelihood of:

• Elevated hematocrit
• Acne
• Fluid retention
• Changes in estradiol
• Blood-pressure changes
• Fertility suppression
• Other unwanted effects

The better objective is:

Appropriate testosterone levels + symptom improvement + acceptable safety markers

For more on realistic treatment expectations, read Testosterone Therapy Benefits: What Men Can Realistically Expect.

Who Should Be Evaluated Carefully Before TRT?

Additional evaluation may be especially important for men with:

• Recent heart attack
• Recent stroke
• Uncontrolled hypertension
• Significant heart failure
• Known arrhythmias
• Previous pulmonary embolism
• Previous deep-vein thrombosis
• Elevated hematocrit
• Untreated sleep apnea
• Kidney disease
• Fertility plans
• Prostate concerns

These conditions do not all have the same implications, but they should be reviewed before treatment.

What Cardiovascular Factors Should Be Evaluated Before TRT?

Depending on the patient, evaluation may include:

• Blood pressure
• Cardiovascular history
• Previous heart attack or stroke
• Family history
• Smoking
• Cholesterol
• Glucose
• Hemoglobin A1c
• CBC and hematocrit
• Kidney function
• Sleep-apnea risk
• Body composition
• Current medications

Additional testing may be appropriate depending on symptoms and medical history.

What Should Be Monitored During Testosterone Therapy?

Ongoing monitoring may include:

• Total testosterone
• Free testosterone when appropriate
• CBC
• Hemoglobin
• Hematocrit
• Blood pressure
• PSA when appropriate
• Estradiol when clinically relevant
• Metabolic markers
• Kidney or liver function when relevant
• Symptoms and side effects

Monitoring helps keep treatment individualized over time.

How Often Should TRT Be Reassessed?

There is no single monitoring schedule that is appropriate for every patient.

Frequency may depend on:

• Testosterone formulation
• Dose
• Age
• Cardiovascular health
• Hematocrit
• Symptoms
• Prostate considerations
• Other medical conditions

Treatment should be reassessed periodically rather than continued indefinitely without follow-up.

What Should Men Take Away From the TRAVERSE Study?

TRAVERSE answered one of the most important questions surrounding testosterone therapy.

For appropriately selected men with confirmed testosterone deficiency, TRT did not increase the overall rate of cardiovascular death, nonfatal heart attack, or nonfatal stroke compared with placebo.

That is an important and reassuring finding.

But it does not justify:

• Self-prescribing testosterone
• Using excessively high doses
• Ignoring hematocrit
• Ignoring blood pressure
• Ignoring cardiovascular disease
• Ignoring clotting history
• Skipping follow-up testing

Responsible TRT still requires appropriate diagnosis, dosing, and monitoring.

A Comprehensive Approach to Testosterone Therapy

At RenewFX Health & Wellness, testosterone therapy is not evaluated in isolation.

Care is led by an experienced, board-certified physician specializing in hormone therapy and integrative medicine, with attention to the factors that can influence both symptoms and treatment safety.

Depending on the patient, that may include consideration of:

• Symptoms
• Total and free testosterone
• Medical history
• Cardiovascular health
• Blood pressure
• Hematocrit
• Metabolic health
• Sleep-apnea risk
• Sexual health
• Fertility considerations
• Current medications
• Body composition
• Lifestyle factors
• Treatment goals

This broader, personalized approach helps determine not only whether TRT may be appropriate, but also how treatment should be monitored over time.

Learn more about Testosterone Replacement Therapy at RenewFX.

Physician-Guided Testosterone Therapy in Houston

RenewFX Health & Wellness provides physician-guided testosterone replacement therapy and hormone optimization in Houston, with telemedicine options available for appropriate patients throughout Texas.

Our approach is designed to look beyond a single testosterone result and consider how hormone health may interact with cardiovascular, metabolic, sexual, and overall health.

For additional information, read:

Questions About Testosterone Replacement Therapy

Testosterone Therapy and Cardiovascular Health

Testosterone Therapy Benefits: What Men Can Realistically Expect

How Declining Testosterone Affects Men

Hormone Therapy and Optimization

The Bottom Line

Does TRT increase heart attack or stroke risk?

The TRAVERSE study provided strong evidence that properly prescribed testosterone replacement therapy did not increase the overall rate of cardiovascular death, nonfatal heart attack, or nonfatal stroke compared with placebo in men with confirmed testosterone deficiency and existing or elevated cardiovascular risk.

But cardiovascular safety involves more than heart attacks and strokes.

Blood pressure, hematocrit, heart rhythm, clotting history, metabolic health, sleep apnea, and other medical conditions still matter.

A thoughtful approach to TRT is therefore:

Confirm testosterone deficiency → evaluate overall health → personalize treatment → monitor response and safety → reassess over time

Considering Testosterone Therapy?

If you’re experiencing low energy, reduced libido, loss of strength, changes in body composition, or other symptoms that may be related to low testosterone, the next step is a comprehensive medical evaluation.

RenewFX provides physician-guided hormone care with an emphasis on careful assessment, individualized treatment, and ongoing monitoring.

Schedule a consultation with RenewFX or call 713-936-4103.