Some beta blockers cause vasodilation, but many do not. In fact, the older and most widely prescribed beta blockers tend to do the opposite: they tighten peripheral blood vessels. Only a subset, sometimes called third-generation or vasodilating beta blockers, actively relax arteries while still blocking beta receptors in the heart. The difference between these two groups has real consequences for blood pressure control, metabolic health, and side effects that patients care about.
Traditional Beta Blockers Tend to Constrict Blood Vessels
When people think of beta blockers, they usually picture drugs like atenolol, metoprolol, or propranolol. These are effective at slowing the heart rate and reducing the force of each heartbeat, which lowers blood pressure. But in the peripheral blood vessels, their effect is less intuitive. By blocking beta-2 receptors on blood vessel walls, they remove a signal that normally helps those vessels relax. At the same time, the unopposed activity of alpha receptors can cause the smooth muscle in arteries to tighten. The net result is an increase in peripheral vascular resistance, meaning the arteries get somewhat narrower rather than wider.
A large systematic review and network meta-analysis confirmed this pattern across multiple drugs. Peripheral vasoconstriction was reported in about 7% of patients taking beta blockers compared to roughly 5% in control groups, a small but statistically meaningful difference. Atenolol and propranolol carried a significantly higher risk of this constriction than placebo did. Interestingly, the analysis found that this tendency was not simply related to whether the drug preferred beta-1 receptors over beta-2 receptors. Some drugs with partial agonist activity, like pindolol and acebutolol, did not show a higher constriction rate than placebo.1Europe PMC. Peripheral vasoconstriction induced by β-adrenoceptor blockers: a systematic review and a network meta-analysis
This vasoconstriction is one reason older beta blockers can cause cold hands and feet, a complaint doctors hear frequently. It also helps explain why these drugs, despite being excellent at controlling heart rate, have sometimes been criticized for not lowering blood pressure as effectively as drugs that directly relax blood vessels. The antihypertensive effect of traditional beta blockers comes primarily from slowing the heart and reducing the amount of renin the kidneys release, which in turn lowers the activity of the hormonal system that squeezes arteries. Research from early studies of beta blocker mechanisms found a strong correlation between how much a beta blocker suppressed renin levels and how much it lowered blood pressure.2Elsevier / The American Journal of Medicine. Acute and long-term studies of the mechanisms of action of beta-blocking drugs in lowering blood pressure
Third-Generation Beta Blockers and How They Relax Arteries
The drugs that genuinely cause vasodilation belong to what is often called the third generation of beta blockers. The three most prominent members are carvedilol, labetalol, and nebivolol. Unlike their predecessors, these drugs lower blood pressure partly by reducing peripheral vascular resistance while maintaining or even increasing the amount of blood the heart pumps with each beat.3Canadian Journal of Cardiology. Contemporary Use of β-Blockers: Clinical Relevance of Subclassification The way they accomplish this vasodilation, however, differs from drug to drug.
Alpha-1 Receptor Blockade
Carvedilol and labetalol achieve their vasodilating effects largely by blocking alpha-1 receptors on blood vessel walls. Alpha-1 receptors are what the body uses to tighten arteries, particularly during stress or when the sympathetic nervous system ramps up. By blocking both beta receptors (in the heart) and alpha-1 receptors (in the arteries), these drugs hit both sides of the blood pressure equation at once. A clinical study of carvedilol confirmed that at the doses used in practice, the drug produces substantial alpha-1 blocking effects alongside its beta-blocking activity.4PubMed. Alpha 1-blocking properties of carvedilol during acute and chronic administration Carvedilol has relatively greater alpha-blocking potency compared to labetalol, which also blocks alpha-1 receptors but to a lesser degree.5PubMed. Beta blockers in the management of chronic kidney disease
Nitric Oxide Release
Nebivolol takes a completely different route to vasodilation. Rather than blocking alpha receptors, it stimulates the production of nitric oxide in the lining of blood vessels. Nitric oxide is the body’s most powerful natural signal for arterial relaxation. Nebivolol triggers this by activating beta-3 receptors on the endothelium, a receptor subtype that the other beta blockers largely ignore.6PubMed. Nitric oxide mechanisms of nebivolol
The evidence for this mechanism is detailed. In laboratory studies, nebivolol relaxed coronary resistance arteries in a dose-dependent way, and this relaxation was blocked when nitric oxide production was inhibited. The drug increased nitric oxide release from endothelial cells by around 200%. When the same experiment was performed in mice that lacked beta-3 receptors, nebivolol failed to relax their arteries at all, confirming that this specific receptor is the gatekeeper.7PubMed. Endothelial beta3-adrenoreceptors mediate nitric oxide-dependent vasorelaxation of coronary microvessels in response to the third-generation beta-blocker nebivolol The relaxation also depended on having a functional endothelium, the thin inner lining of blood vessels. If the endothelium was damaged, as it commonly is in people with long-standing high blood pressure or diabetes, the vasodilating effect could be diminished.
Beta-2 Agonism
A less well-known mechanism shows up in celiprolol, a beta blocker with a pharmacological profile that is genuinely unusual. Celiprolol blocks beta-1 receptors in the heart but actually stimulates beta-2 receptors on blood vessels, effectively telling those vessels to relax rather than tighten.8PubMed Central. Celiprolol: A Unique Selective Adrenoceptor Modulator Microvascular studies found that this vasodilation was more pronounced in smaller arteries than in larger ones, and that it was indeed mediated through beta-2 receptors.9PubMed. Celiprolol exerts microvascular dilatation by activation of beta 2-adrenoceptors The doses needed to stimulate beta-2 receptors were considerably lower than those needed to block them, so in practice the drug’s vasodilatory effect kicks in before any opposing constriction would.10PubMed. Celiprolol: agonist and antagonist effects at cardiac beta 1- and vascular beta 2-adrenoceptors determined under in vivo conditions in the rat
Why This Distinction Matters for Blood Pressure
You might assume that a lower reading on a standard arm cuff tells the whole story, but blood pressure measured at your arm is not the same as blood pressure at your aorta or coronary arteries. Traditional beta blockers can lower brachial blood pressure quite well while leaving central aortic pressure relatively high. Vasodilating beta blockers, by contrast, reduce both. A comparative study found that even when arm blood pressure readings were identical across groups, patients taking atenolol had significantly higher central systolic blood pressure and greater arterial wave reflection than patients on vasodilating beta blockers or angiotensin receptor blockers.11Blood Pressure Monitoring. Different patterns of peripheral versus central blood pressure in hypertensive patients treated with β-blockers either with or without vasodilator properties or with angiotensin receptor blockers
Central blood pressure matters because it is what the heart, brain, and kidneys actually feel. A drug that brings down the arm reading but leaves high pressure waves bouncing back from stiff peripheral arteries is doing a less complete job of protecting those organs. The vasodilating beta blockers reduce peripheral vascular resistance, which in turn reduces the intensity of those reflected waves. This favorable hemodynamic profile includes decreases in central aortic pressure that traditional beta blockers do not reliably produce.12PubMed. The vasodilatory beta-blockers
Metabolic Side Effects and Insulin Sensitivity
One of the longstanding knocks against beta blockers has been their tendency to worsen insulin sensitivity and nudge blood sugar and cholesterol in the wrong direction. This is a real concern with conventional beta blockers. The mechanism appears to be closely linked to what happens in the blood vessels: when peripheral arteries constrict, blood flow to skeletal muscle drops, and muscles are where a large share of insulin-mediated glucose uptake happens. Less flow means less glucose disposal, which means higher blood sugar and greater insulin resistance over time.
Vasodilating beta blockers sidestep this problem. Studies of carvedilol, celiprolol, and dilevalol found that none of them decreased insulin sensitivity the way traditional agents did. The explanation is straightforward: because these drugs relax arteries rather than tightening them, peripheral blood flow is maintained, and the metabolic penalty of reduced vascular resistance never materializes. The vasodilating effect, whether through alpha-1 blockade or beta-2 stimulation, appears to more than offset whatever metabolic harm comes from blocking beta receptors themselves.13PubMed. Beta-blocking agents in patients with insulin resistance: effects of vasodilating beta-blockers
For someone who already has metabolic syndrome or is at risk for type 2 diabetes, this difference can be clinically meaningful. A doctor choosing between metoprolol and carvedilol for a patient with both high blood pressure and prediabetes has a reason to lean toward the vasodilating option.
Erectile Function
Sexual side effects are among the most common reasons people stop taking beta blockers, and the vasodilation question is directly relevant here. Erections depend heavily on nitric oxide signaling in penile blood vessels: NO triggers relaxation of smooth muscle, allowing blood to flow in and the tissue to engorge. A drug that enhances nitric oxide, like nebivolol, would be expected to cause fewer problems in this area than one that does not.
The evidence supports that expectation. A review of clinical studies found that nebivolol either significantly improved erectile function or at least did not worsen it, in contrast to conventional beta blockers.14PubMed Central. Nebivolol versus other beta blockers in patients with hypertension and erectile dysfunction A randomized crossover trial comparing nebivolol and metoprolol head-to-head in men with high blood pressure found that metoprolol caused a significant decline in erectile function scores across multiple subtypes of erectile difficulty, while nebivolol did not. The study also measured circulating nitric oxide levels and found that they did not change with metoprolol but increased significantly with nebivolol.15PubMed. Nebivolol protects erectile functions compared to Metoprolol in hypertensive men with atherogenic, venogenic, psychogenic erectile dysfunction That finding ties the functional benefit directly back to the nitric oxide mechanism.
Vasodilating Beta Blockers in Heart Failure
Carvedilol is one of the beta blockers with the strongest evidence base in heart failure, and its vasodilating property is part of the story. In heart failure, the heart is struggling to pump enough blood, and the body compensates by tightening peripheral arteries to maintain blood pressure. This extra resistance, however, makes the heart’s job even harder over time. A drug that can block the harmful effects of excess adrenaline on the heart (via beta blockade) while simultaneously reducing the resistance the heart pumps against (via alpha-1 blockade) addresses both problems.
A study of the mechanisms behind carvedilol’s benefit in heart failure broke down how the drug improved ejection fraction, a measure of how well the heart pumps. In patients who showed meaningful improvement, roughly 60% of the gain came from the drug slowing the heart rate (giving it more time to fill), about 30% came from improved contractility, and less than 20% came from the decrease in total peripheral resistance.16PubMed. Mechanisms underlying improvements in ejection fraction with carvedilol in heart failure The vasodilation contribution was the smallest slice, but in a patient whose heart is barely keeping up, every bit of afterload reduction counts. Carvedilol also has antioxidant properties and antiproliferative effects on smooth muscle cells, which may offer additional vascular protection beyond the acute hemodynamic benefit.17PubMed. Results of therapy with carvedilol, a beta-blocker vasodilator with antioxidant properties, in hypertensive patients
Kidney Considerations
The kidneys are exquisitely sensitive to blood flow, and changes in vascular resistance ripple through renal function quickly. Traditional beta blockers, by raising peripheral resistance, can reduce blood flow to the kidneys. Vasodilating beta blockers behave differently here. A review of their use in chronic kidney disease noted that newer vasodilating agents have better tolerability and distinct effects on renal hemodynamics, with carvedilol’s relatively greater alpha-blocking potency translating to more favorable renal blood flow patterns compared to labetalol.5PubMed. Beta blockers in the management of chronic kidney disease
For patients who need a beta blocker and also have impaired kidney function, the vasodilating agents offer a theoretical and practical advantage: they do not add the hemodynamic insult of increased renal vascular resistance on top of whatever kidney damage already exists.
Cold Hands, Raynaud’s, and Peripheral Circulation
Cold extremities are a classic beta blocker side effect, and the assumption has always been that cardioselective or partial-agonist beta blockers would be gentler on finger and toe circulation than nonselective ones. A study in patients with Raynaud’s phenomenon and hypertension challenged that assumption. After single doses of propranolol (nonselective), metoprolol (cardioselective), and pindolol (partial agonist), none of the three showed a significant adverse effect on finger skin blood flow compared to placebo, and no clear advantage emerged for cardioselectivity or partial agonist activity in protecting peripheral perfusion after cold exposure.18PubMed Central. The influence of different beta-blocking drugs on the peripheral circulation in Raynaud’s phenomenon and in hypertension
That said, this was a single-dose study, and chronic use may tell a different story. The larger meta-analysis mentioned earlier did find that drugs like propranolol and atenolol caused more peripheral vasoconstriction over longer use. For someone who already has poor circulation in their hands and feet, a vasodilating beta blocker that actively lowers peripheral resistance would be a logical choice, though clinical guidelines on this point are less definitive than the pharmacology would suggest.
Genetic Variation in Vascular Response
Not everyone’s blood vessels respond the same way to the same drug, and genetics is one reason. Variation in the gene encoding the beta-2 receptor influences how strongly a person’s arteries dilate in response to beta-2 stimulation. A study that measured vascular resistance while directly activating beta-2 receptors found that people carrying the Gly16 variant of the receptor gene had lower vascular resistance in response to a beta-2 agonist than those with the Arg16 variant.19PubMed Central. beta2-Adrenoceptor gene variation and systemic vasodilatation during ganglionic blockade
This matters in practice because a drug like celiprolol, which vasodilates by stimulating beta-2 receptors, might work better in some genetic backgrounds than others. Similarly, individual variation in endothelial function could affect how much nitric oxide a patient produces in response to nebivolol. Pharmacogenomics in this field is still early, but it helps explain why two patients on the same beta blocker at the same dose can have noticeably different side-effect profiles and blood pressure responses.
Additional Vascular Properties Beyond Simple Vasodilation
Carvedilol stands out among the vasodilating beta blockers for doing more than just relaxing arteries. Research has shown that the drug also has antioxidant activity, scavenging oxygen free radicals that damage blood vessel walls, and antiproliferative effects that slow the abnormal growth of smooth muscle cells inside arteries.17PubMed. Results of therapy with carvedilol, a beta-blocker vasodilator with antioxidant properties, in hypertensive patients These are not vasodilation per se, but they contribute to vascular health in ways that a simple vasodilator does not. The antioxidant effect may be one reason carvedilol performs well in heart failure trials beyond what its hemodynamic profile alone would predict.
Nebivolol’s nitric oxide stimulation, meanwhile, has downstream effects that go beyond relaxing artery walls. Nitric oxide also inhibits platelet aggregation (reducing clot formation), discourages white blood cells from sticking to the vessel lining (a step in atherosclerosis), and influences how the endothelium repairs itself. The beta-3 receptor pathway nebivolol activates was even shown to promote the formation of new capillary networks in animal models, suggesting the drug may have angiogenic properties in addition to its vasodilatory ones.7PubMed. Endothelial beta3-adrenoreceptors mediate nitric oxide-dependent vasorelaxation of coronary microvessels in response to the third-generation beta-blocker nebivolol Whether this translates to measurable clinical benefit in humans beyond blood pressure lowering remains an open question, but it illustrates just how much the pharmacology of these drugs has evolved from the first-generation agents that simply slowed the heart.