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For more than half a century, drugs known as beta blockers have been a mainstay for managing heart disease, especially for heart attack survivors. But doctors are now reconsidering that strategy, based on growing evidence showing that for some people who have had a heart attack, beta blockers might not offer any meaningful benefit. “For people whose hearts still pump normally after a heart attack, doctors may now think twice about prescribing a beta blocker,” says Dr. Cian McCarthy, a cardiologist at Harvard-affiliated Massachusetts General Hospital.
Sometimes, however, a heart attack leaves the left ventricle (the heart’s main pumping chamber) unable to contract effectively. When that’s the case, beta blockers are still recommended, he says. These drugs are also prescribed to treat angina (chest pain caused by narrowed heart arteries), to treat heart failure, to suppress abnormal heart rhythms such as atrial fibrillation, and to treat high blood pressure.
What are beta blockers?
You can identify beta blockers by their generic names — they all end in “lol.” Common examples include
- atenolol (Tenormin)
- bisoprolol
- carvedilol (Coreg)
- metoprolol (Lopressor, Toprol)
- nadolol
- propranolol (Inderal, InnoPran).
How do beta blockers work in the body?
Beta blockers work by blocking beta receptors, which are tiny proteins on the outer surfaces of cells throughout the body — notably in the heart, blood vessel walls, lungs, kidneys, and brain. Stress hormones (namely, epinephrine and norepinephrine) stimulate beta receptors, triggering effects that vary depending on the organ. In the heart and blood vessels, epinephrine and norepinephrine speed up the heart, strengthen the heart’s contractions, and tighten blood vessel walls.
Beta blockers subvert those effects by settling onto beta receptors and preventing the stress hormones from binding to them. As a result, the heart slows down and the blood vessels relax, actions that lower blood pressure and reduce the heart’s workload.
Common side effects of beta blockers
Beta blockers’ side effects are usually not life-threatening. But because beta receptors are found in so many different tissues, these drugs can have unwanted effects throughout the body, such as
- drowsiness or fatigue
- dizziness or lightheadedness
- cold hands and feet
- constipation
- erectile dysfunction.
Less common side effects include allergic reactions (such as rashes and swelling of the face) and trouble sleeping. If you have side effects from a beta blocker, talk to your doctor.
Beta blockers after a heart attack
A recent study examined the role of beta blockers in more than 8,500 heart attack survivors with normal or slightly impaired heart function. Half were randomly assigned to start taking a beta blocker within two weeks of leaving the hospital; the others did not take beta blockers. Over the following four years, researchers found no difference in repeat heart attacks, hospitalizations for heart failure, or death from any cause between the two groups. Published Aug. 30, 2025, in The New England Journal of Medicine, the findings apply to people with heart function that’s normal or only mildly reduced, defined as an ejection fraction of 40% or greater. The ejection fraction refers to the percentage of the blood that the heart sends out to the rest of the body each time it contracts. An ejection fraction of 50% to 70% is considered normal.
Who should — and shouldn’t — take beta blockers?
If you’ve had a heart attack and have what’s called a reduced ejection fraction (an ejection fraction below 40%), a beta blocker still makes sense. People with mildly reduced ejection fraction (40% to 49%) also likely benefit from beta blockers. But if you have a preserved ejection fraction (40% or higher), a beta blocker may not be needed. What if you have a preserved ejection fraction and are already on a beta blocker? “It may be reasonable to stop taking it one year after your heart attack, provided you don’t need the drug for another reason,” says Dr. McCarthy.
Beta blockers are generally less effective than other blood pressure drugs for preventing cardiovascular problems, especially strokes. “But while beta blockers aren’t a first-line choice, they can still be a useful addition if your blood pressure remains uncontrolled while you’re on other drugs,” Dr. McCarthy says.
Beta blockers are also used to prevent migraine attacks and decrease hand tremors. They can dampen common symptoms of anxiety such as sweating, rapid heartbeat, and blushing. Beta blocker eye drops are routinely prescribed to lower eye pressure in people with glaucoma. If you’re currently taking a beta blocker for any reason, don’t stop taking it before talking to your doctor.
This article appears in the January 2026 issue of Harvard Heart Letter under the title “New thinking on beta blocker use.”
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