Testosterone and Heart Disease: 7 Risks Every Man Should Know
Testosterone therapy has become one of the fastest-growing treatments in men’s health, promoted for energy, strength, libido, and mood. For years, though, men and their doctors worried about a possible link between testosterone and heart disease. Now a large clinical trial and a 2025 FDA labeling change have reshaped that conversation.
So is testosterone safe for your heart? For many men with true low testosterone, the answer is reassuring, but there are still real cardiovascular risks to know and monitor. Here are seven, from a cardiologist’s perspective.
1. Low Testosterone and Heart Risk: Association Versus Causation
Men with low testosterone are more likely to have heart disease, diabetes, obesity, and metabolic syndrome. But that doesn’t necessarily mean low testosterone causes heart disease.
In many cases, the relationship runs the other way, or both share a common cause. Excess belly fat, poorly controlled diabetes, sleep apnea, chronic illness, certain medications, and heavy alcohol use can all lower testosterone and raise heart risk at the same time. In this sense, low testosterone can be a marker of poor overall health rather than the root problem.
What it means for you: If you have low testosterone, it’s worth looking for and treating the underlying causes, such as weight, sleep apnea, and blood sugar, along with checking your heart risk. Raising testosterone alone hasn’t been shown to prevent heart attacks or strokes.
2. Testosterone Therapy and Heart Attacks: What the TRAVERSE Trial Showed
Concern about heart attacks grew after several observational studies in the early 2010s suggested higher risk in men taking testosterone. In 2015, the FDA added a cardiovascular warning to testosterone labels and required a large safety trial.
That trial was TRAVERSE, published in the New England Journal of Medicine in 2023. It enrolled 5,246 men ages 45 to 80 with symptoms of low testosterone, confirmed low levels on two blood tests, and either existing heart disease or a high risk of it. Men received a daily testosterone gel or a placebo and were followed for an average of nearly three years.
The result: heart attacks, strokes and cardiovascular deaths occurred in 7.0% of men on testosterone versus 7.3% on placebo. Testosterone did not increase the risk of major cardiovascular events.
Based on TRAVERSE, in February 2025 the FDA removed the cardiovascular-outcomes language from the boxed warning on testosterone products.
Important limits: TRAVERSE was designed to test safety, not benefit, so it didn’t show that testosterone protects the heart. It studied men with confirmed low testosterone, treated with a gel to normal levels and carefully monitored. It doesn’t apply to men with normal testosterone, or to high-dose or performance-enhancing use. The FDA continues to limit approval to men with low testosterone caused by a medical condition, not age alone.
3. Testosterone and Blood Pressure: Potential Increases During Treatment
While the FDA removed the heart attack language, it added a blood pressure warning to all testosterone products in 2025. Studies using 24-hour ambulatory blood pressure monitoring confirmed that testosterone can raise blood pressure across all forms of the drug.
Even modest increases matter over time, especially for men who already have high blood pressure or heart disease.
What it means for you: Check your blood pressure before starting testosterone and regularly during treatment, ideally with a home monitor. If it rises, your doctor may adjust your dose, change the formulation or treat your blood pressure. Learn how high blood pressure damages your body.
4. Testosterone and Atrial Fibrillation: The AFib Signal in Clinical Trials
TRAVERSE found a signal for heart rhythm problems. Compared with placebo, men taking testosterone had more:
- Atrial fibrillation: 3.5% vs 2.4%
- Nonfatal arrhythmias requiring treatment: 5.2% vs 3.3%
Atrial fibrillation, an irregular and often rapid heartbeat, raises the risk of stroke and heart failure if it isn’t recognized and treated.
What it means for you: Tell your doctor right away about palpitations, a racing or irregular heartbeat, dizziness, or new shortness of breath while on testosterone. Men with a history of AFib should discuss the risks carefully with their cardiologist before starting.
5. Testosterone and Blood Clots: Venous Thromboembolism and Pulmonary Embolism
In TRAVERSE, pulmonary embolism, a blood clot in the lungs, occurred in 0.9% of men on testosterone versus 0.5% on placebo. The numbers are small, but the difference is meaningful because pulmonary embolism can be life-threatening.
The risk may be higher in men with a prior blood clot, an inherited clotting disorder, recent surgery or immobility, obesity, or a high red blood cell count.
What it means for you: Seek care right away for swelling, pain or warmth in one leg, sudden shortness of breath, sharp chest pain that worsens with a deep breath, or coughing up blood. Learn more about leg symptoms in our post on poor circulation in your legs, and the emergency signs of pulmonary embolism in 7 life-threatening cardiac emergencies.
6. Testosterone-Induced Erythrocytosis: High Hematocrit and Monitoring
Testosterone stimulates the bone marrow to make more red blood cells. In some men, this causes erythrocytosis, an abnormally high red blood cell count, measured by the hematocrit. It’s one of the most common side effects of testosterone therapy.
Thicker blood may raise the risk of blood clots, stroke, and heart problems. Erythrocytosis is more common with injections, especially at higher doses, than with gels or patches, and is more likely in men who smoke, have sleep apnea, or live at high altitude.
Monitoring: Expert guidelines generally recommend checking hematocrit before starting testosterone, again about 3 to 6 months after starting, and then at least yearly. If hematocrit rises above about 54%, treatment is usually paused or the dose lowered until it comes down. Treating sleep apnea and switching to a different formulation may also help.
7. Testosterone in Men With Coronary Artery Disease: An Individualized Decision
Many men considering testosterone already have coronary artery disease, a stent or a prior heart attack. TRAVERSE is reassuring here, since about half of its participants had existing heart disease. But that doesn’t mean testosterone is right for every man with heart disease.
A careful decision should consider:
- Confirmed low testosterone on at least two early-morning blood tests, plus real symptoms
- Recent heart events. Treatment is generally avoided for several months after a heart attack or stroke.
- Uncontrolled heart failure, which can worsen with fluid retention
- Blood pressure control, atrial fibrillation history, and blood clot history
- Baseline hematocrit and untreated sleep apnea
- Your goals, and whether the expected benefits outweigh the risks
For men with heart disease, we recommend that your cardiologist and the doctor prescribing testosterone work together. Testosterone should never replace proven heart treatments such as statins, blood pressure control, and exercise. Read statin myths vs. facts.
Testosterone Therapy Heart Monitoring Checklist
| What to check | Before starting | During treatment |
|---|---|---|
| Testosterone level | Two early-morning tests | 3–6 months, then yearly |
| Hematocrit | Yes | 3–6 months, then at least yearly |
| Blood pressure | Yes, ideally home readings | Regularly, especially after dose changes |
| Heart rhythm symptoms | Review history of AFib or palpitations | Report palpitations or dizziness promptly |
| Clot risk | Review prior clots and family history | Report leg swelling or sudden breathlessness |
| Sleep apnea | Screen if snoring or daytime sleepiness | Treat if present |
| Prostate health | PSA per your doctor | As recommended |
Who Should Be Cautious About Testosterone?
Talk with a cardiologist before starting, or reconsider treatment, if you have:
- A heart attack or stroke in the past several months
- Uncontrolled high blood pressure or heart failure
- A history of blood clots or pulmonary embolism
- Atrial fibrillation or other significant rhythm problems
- A hematocrit that’s already high, or untreated severe sleep apnea
And be wary of testosterone obtained without confirmed low levels, at doses above the normal range, or from sources that don’t provide regular lab monitoring.
Frequently Asked Questions
Does testosterone therapy cause heart attacks? In the TRAVERSE trial, testosterone did not increase the risk of heart attack, stroke, or cardiovascular death in men with confirmed low testosterone and heart disease or high heart risk. Based on that trial, the FDA removed the heart-outcomes language from the boxed warning in 2025. Testosterone can still raise blood pressure and is linked to higher rates of atrial fibrillation and blood clots, so monitoring matters.
Can low testosterone cause heart disease? Low testosterone is associated with heart disease, but it isn’t clear that it causes it. Obesity, diabetes, sleep apnea, and chronic illness can both lower testosterone and raise heart risk. Treating those conditions is important whether or not you take testosterone.
Is testosterone safe if I have a stent or had a heart attack? It may be, depending on your situation. Many men in TRAVERSE had existing heart disease. However, treatment is usually avoided in the months after a heart attack or stroke, and the decision should be made together with your cardiologist.
Do testosterone injections or gels carry different heart risks? TRAVERSE studied a daily gel. Injections, especially high-dose or infrequent injections, cause larger swings in testosterone levels and are more likely to raise hematocrit. The best formulation depends on your health and preferences.
What should I monitor while on testosterone? At minimum: testosterone levels, hematocrit, blood pressure and any symptoms such as palpitations, leg swelling, or shortness of breath. Your doctor may also check PSA and other labs.
Get a Cardiologist's Perspective on Testosterone Therapy in Tampa
Whether you’re considering testosterone, already taking it, or have heart disease and want to know if it’s safe for you, we can help. Our board-certified interventional cardiologist will review your heart risk, blood pressure, rhythm history and labs, and coordinate with the doctor who prescribes your testosterone so your treatment is as safe as possible.
Not sure if your symptoms need attention? See the 10 warning signs you should see a cardiologist. Active men can also read about athlete’s heart and when to worry.
Request an appointment or call (813) 540-4322.
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Sources
- Cardiovascular Safety of Testosterone-Replacement Therapy (TRAVERSE) — New England Journal of Medicine (2023)
- Testosterone Doesn’t Cause CV Events in High-Risk Men With Hypogonadism — TCTMD
- Cardiovascular Safety of Testosterone-Replacement Therapy: Journal Scan — American College of Cardiology
- FDA Issues Class-Wide Labeling Changes for Testosterone Products — U.S. Food and Drug Administration (February 2025)