What did the TRAVERSE trial find?
It found a small rise in atrial fibrillation alongside reassuring heart attack and stroke results. TRAVERSE enrolled 5,246 men aged 45 to 80 who had symptoms of low testosterone, two fasting levels under 300 ng/dL, and either heart disease or a high risk of it. They used testosterone gel, adjusted to keep levels between 350 and 750 ng/dL, or a placebo gel.
The AndroGel 1.62% label now lists the rhythm findings, shown here with the trial’s main heart outcome:
| Outcome in TRAVERSE | Testosterone | Placebo |
|---|---|---|
| Atrial fibrillation | 3.5% | 2.4% |
| Nonfatal arrhythmias needing treatment | 5.2% | 3.3% |
| Acute kidney injury | 2.3% | 1.5% |
| Cardiovascular death, nonfatal heart attack or stroke | 7.0% | 7.3% |
The FDA’s 2025 labeling change added TRAVERSE results to all testosterone products. The trial does not prove testosterone causes atrial fibrillation in every man, and it studied older men with heart risk using a gel, so younger, healthier men on other forms were not directly tested. It is still a signal worth taking seriously.
Which palpitations should you report?
Report any new sense that your heartbeat is irregular, racing or pounding without a reason. MedlinePlus lists the symptoms of atrial fibrillation as:
- Extreme fatigue, the most common symptom
- Palpitations, the feeling that your heart is skipping, fluttering, pounding or beating too fast
- Trouble breathing, especially when lying down or exercising
- Chest pain
- Dizziness or fainting
Some people have no symptoms at all and learn about it from a pulse check or a watch alert. An occasional skipped beat is a different thing from a stretch of fast, irregular beating that lasts minutes or keeps coming back.
Chest pain, fainting, or sudden weakness, facial drooping or trouble speaking needs a call to 911 right away. MedlinePlus notes that stroke symptoms often come on suddenly, and atrial fibrillation raises the risk of stroke.
When is an ECG warranted?
When symptoms are happening, or when a pulse check or watch suggests an irregular rhythm. MedlinePlus explains that the diagnosis usually rests on an electrocardiogram (ECG or EKG), sometimes with an echocardiogram. Because atrial fibrillation can come and go, an ECG taken during symptoms tells you more than one taken days later.
Your primary doctor, an urgent care center or an emergency department can perform one. If you have a history of rhythm problems, tell your provider before you start testosterone so a baseline can be considered.
Who is more likely to develop atrial fibrillation?
The same men who are at risk without testosterone. MedlinePlus lists older age, especially over 65, high blood pressure, obesity, sleep apnea, diabetes, heart failure, an overactive thyroid, heavy alcohol use and smoking. Several of these overlap with low testosterone, and testosterone labels now warn that treatment can raise blood pressure. Our page on whether TRT raises blood pressure covers that link, and our page for men with heart disease explains how a cardiac history changes the plan.
Does atrial fibrillation mean stopping TRT?
Not automatically, but it means a pause to review. The decision depends on how the rhythm is managed, your stroke risk, your blood pressure and how much testosterone is helping you. It should be made together with the cardiologist treating the rhythm. Our page on TRT warning signs and when to call lists other symptoms worth reporting.
How Ultimate Male approaches heart rhythm concerns
Before starting, your provider reviews your heart history, any rhythm problems and the medicines you take, and your plan includes regular blood pressure checks as testosterone labels advise. If you notice palpitations on treatment, call the clinic the same day; the provider will advise where to get an ECG and then decide whether your dose, form or treatment itself should change.
The first step is a free 10-minute call, then labs on site in San Gabriel or Downey and a consultation about whether testosterone therapy makes sense for your heart and your goals.
