Beta blockers are a class of medications that slow your heart rate and lower blood pressure by blocking the effects of adrenaline and related stress hormones on your heart and blood vessels. The most commonly prescribed beta blockers include metoprolol (Lopressor, Toprol XL), atenolol (Tenormin), propranolol (Inderal), carvedilol, bisoprolol, nebivolol (Bystolic), nadolol, and acebutolol. Each one works slightly differently depending on which receptors it targets in the body.
How Beta Blockers Work
Your body produces stress hormones called catecholamines, most notably adrenaline and noradrenaline. These hormones bind to receptors on your heart and blood vessels to speed up your heart rate, increase the force of each heartbeat, and tighten blood vessels. Beta blockers sit on those same receptors and block the hormones from attaching, so the signals never get through. The result is a slower heart rate, lower blood pressure, and less strain on your cardiovascular system.
There are two main types of beta receptors that matter. Beta-1 receptors are concentrated in the heart, while beta-2 receptors are found in the lungs, blood vessels, and other tissues. This distinction is what separates beta blockers into different categories, because some drugs block only the heart receptors while others block both.
Cardioselective Beta Blockers
Cardioselective (or “beta-1 selective”) beta blockers primarily target the heart. Because they mostly leave lung receptors alone, they’re generally considered a better option for people with mild respiratory conditions. The most widely used cardioselective beta blockers are:
- Metoprolol (Lopressor, Toprol XL): one of the most frequently prescribed beta blockers overall, available in both immediate-release and extended-release forms
- Atenolol (Tenormin): a once-daily option commonly used for high blood pressure
- Bisoprolol: often used in heart failure management
- Nebivolol (Bystolic): a newer beta-1 selective agent with additional blood vessel-relaxing properties
- Acebutolol: less commonly prescribed but still used for high blood pressure and irregular heart rhythms
- Betaxolol (Kerlone): approved for hypertension, also available as eye drops for glaucoma
Non-Selective Beta Blockers
Non-selective beta blockers block both beta-1 receptors in the heart and beta-2 receptors in the lungs and blood vessels. This broader action makes them useful for certain conditions but also increases the risk of respiratory side effects. The main non-selective beta blockers include:
- Propranolol (Inderal LA, InnoPran XL): the original beta blocker, still widely used for high blood pressure, tremor, and off-label for anxiety and migraine prevention
- Nadolol: a long-acting option taken once daily
- Carvedilol: blocks both beta receptors and alpha receptors, giving it blood vessel-relaxing properties on top of its heart-slowing effects
- Timolol: commonly used as eye drops for glaucoma, though oral forms exist
Third-Generation Beta Blockers
Nebivolol and carvedilol are sometimes called third-generation beta blockers because they do something older versions don’t: they relax blood vessels. Traditional beta blockers can actually increase resistance in your blood vessels, which partly offsets their blood pressure benefits. Nebivolol and carvedilol stimulate the release of nitric oxide from blood vessel walls, which causes them to widen. This means they lower blood pressure without reducing the heart’s pumping efficiency as much, and without the increase in vascular resistance that older beta blockers can cause.
What Beta Blockers Are Prescribed For
The primary approved uses for beta blockers include high blood pressure, heart failure, and certain abnormal heart rhythms. Different individual drugs carry different specific approvals, but as a class they are a cornerstone of cardiovascular treatment. Metoprolol and bisoprolol, for example, have strong evidence supporting their use in heart failure. Atenolol and betaxolol are commonly used for hypertension alone.
Beta blockers are also widely prescribed off-label. Propranolol is the most common choice for situational anxiety, like stage fright or public speaking nervousness. It doesn’t treat the psychological roots of anxiety, but it dials down the physical symptoms: racing heart, shaky hands and voice, sweating. A 2016 review found that short-term propranolol had effects on anxiety comparable to those of benzodiazepines, though it wasn’t very effective for broader social phobias. Beta blockers are also used off-label for migraine prevention, essential tremor, and certain thyroid conditions.
Common Side Effects
A nationwide study found that roughly 14% of people starting a beta blocker experienced at least one side effect within the first year. The most frequently reported issues were anxiety or insomnia (6.2%), gastrointestinal problems like nausea or stomach upset (4.6%), and erectile dysfunction (4.7%). Compared to people taking calcium channel blockers (another class of blood pressure medication), those on beta blockers had about 50% higher rates of depression, anxiety or insomnia, and dizziness or fainting.
Fatigue is another commonly reported side effect, and many people notice cold hands and feet because beta blockers reduce blood flow to the extremities. Slower heart rate is the intended effect, but if it drops too low you may feel lightheaded or unusually tired. These side effects are often most noticeable in the first few weeks and may improve as your body adjusts.
Who Should Avoid Them
Beta blockers can trigger bronchospasm, a tightening of the airways, which makes them problematic for people with asthma. Non-selective beta blockers like propranolol and timolol carry the highest respiratory risk because they block the beta-2 receptors in the lungs that help keep airways open. Analysis of adverse event reports suggests that metoprolol, nebivolol, and nadolol may be safer choices for people with asthma, while betaxolol, bisoprolol, timolol, and propranolol should be avoided in that group.
People with certain types of heart block, where electrical signals travel abnormally slowly through the heart, generally should not take beta blockers because the drugs slow conduction further. The same caution applies to people with very low heart rates or severely low blood pressure. If you have diabetes, beta blockers can sometimes mask the warning signs of low blood sugar, like a racing heart, so closer blood sugar monitoring is important.