Does Viagra lower blood pressure?

Just like anything else in life, erectile dysfunction (ED) does not occur in a vacuum. In fact, it often occurs alongside other health conditions, such as high blood pressure (aka hypertension). And since Viagra (sildenafil)is commonly prescribed for ED, you might be curious how, if at all, the medication affects your blood pressure. So, does Viagra lower blood pressure? Slightly—but that’s the short answer. 

Here, we’ll explore the connection between Viagra and blood pressure. We’ll also discuss notable interactions and precautions to consider if you’re taking Viagra and high blood pressure medications.

Viagra can lower blood pressure, but the reduction is generally minor and does not make much of a difference for most people. Studies show that Viagra can lower systolic blood pressure (i.e. pressure when the heart is squeezing) by around 6 mmHg and diastolic blood pressure (i.e. pressure when the heart is relaxing) by about 4.5 mmHg. This is a small, temporary drop and typically isn’t enough to cause problems or symptoms or lead to any meaningful benefit—a change that healthcare professionals describe as “clinically insignificant.” (For context, normal blood pressure is 120/80 mmHg; the top number is systolic blood pressure and bottom is diastolic blood pressure.)

Research shows that the dip in blood pressure from Viagra is not only small, but also short-lived; it typically goes away within 1–2 hours after taking a dose. Also, keep in mind that while you can take Viagra up to once daily, most people don’t take it all that often. The frequency of sexual intercourse for most men taking the medication is 3–6 times per month on average, according to one study. So, all of these points considered together, the overall impact of Viagra on average blood pressure is probably minimal for most folks. 

So, why does this slight drop in blood pressure occur when on Viagra? Viagra works by blocking an enzyme called phosphodiesterase type 5 (PDE5), which helps increase levels of a substance called cGMP. This process allows the smooth muscle in your blood vessels to relax, improving blood flow throughout the body, including the penis, and, in turn, enabling an erection. When blood vessels relax and widen, this makes it easier for blood to flow, which can cause a slight decrease in blood pressure. 

While the dip in blood pressure is small, it’s important to keep in mind that if you’re taking certain blood pressure medications (e.g. nitrates, alpha-blockers), the combined effect could be more problematic or even dangerous. Check in with your healthcare provider if you have any concerns about how Viagra might affect your blood pressure, especially if you take blood pressure medications.

No, Viagra does not raise your blood pressure. In fact, it slightly lowers it by helping your blood vessels relax and widen, which improves blood flow. 

If your blood pressure has gone up since starting Viagra, there are likely other factors at play. Stress, lifestyle changes, or other medications are a few examples of possible reasons for the rise in blood pressure. It's also possible that an underlying health issue is causing the increase. It’s best to consult with your healthcare provider if your blood pressure is high, and seek medical care right away if you’re having unusual symptoms of chest pain, shortness of breath, or headaches.

You can generally take Viagra if you have high blood pressure and your condition is stable. ED is super common among those assigned male at birth (i.e. men) with high blood pressure; about 40% of men with ED also have hypertension. Having high blood pressure can make it difficult to get an erection because it limits blood flow to the penis and can damage blood vessels over time. In fact, ED can sometimes be an early sign of high blood pressure.

Viagra is usually safe for those with hypertension because its effects are not likely to worsen hypertension. In fact, Viagra appears to have blood pressure-lowering effects. That said, there are some precautions to be aware of when taking Viagra with certain types of blood pressure medications (more about this later).

Additionally, Viagra should not be used if you take nitrates, such as nitroglycerin, to treat angina (a type of chest pain), as this combination can cause a dangerous drop in blood pressure. For the same reason, it’s also important to avoid Viagra if you’re taking guanylate cyclase stimulators like riociguat for pulmonary hypertension (a condition where blood pressure is elevated in the lungs). 

While it’s typically safe to take Viagra with most blood pressure medications, there are a few exceptions. The biggest red flag is nitrates, such as nitroglycerin and isosorbide, as explained above. These medications are more commonly prescribed for issues with heart health, but they also tend to have blood pressure-lowering effects. Mixing nitrates with Viagra can cause your blood pressure to drop too low, which can be life-threatening. If you take nitrates, Viagra isn’t a safe option for you.

Alpha-blocker medications, which are often used to manage symptoms of enlarged prostate, should be used cautiously with Viagra. Examples of alpha-blockers are doxazosin and tamsulosin. Both Viagra and alpha-blockers widen your blood vessels and lower blood pressure, so taking them together can sometimes lead to a bigger drop in blood pressure. This can result in symptoms like dizziness when standing up, lightheadedness, or even fainting.

If you’re already stable on an alpha-blocker, your healthcare provider will likely start you on the lowest dose of Viagra to reduce the chance of your blood pressure dropping too much. Be sure to let them know about all your medications, so they can guide you safely through any potential interactions.

When it comes to taking Viagra with other types of blood pressure medications, big blood pressure changes are unlikely. For instance, in one study, the combination of Viagra 100 mg and amlodipine 5–10 mg (aka Norvasc, which is a calcium channel blocker) caused systolic blood pressure to decrease by an additional 8 mmHg and diastolic by 7 mmHg. Again, this is a mild decrease, and usually not enough to cause problems for most people, especially considering that Viagra’s effects on blood pressure usually wear off within a couple hours and most men do not take it often, as explained above. 

Still, if you’re taking Viagra and any blood pressure medication, it’s a good idea to watch for signs that your blood pressure may be too low, like dizziness or feeling faint. If you notice these symptoms, contact your healthcare provider. They may adjust the dosage of your blood pressure medication, if appropriate, recommend a different one, or suggest trying an alternate treatment for ED.

Side note: Some blood pressure medications (e.g. beta-blockers like propranolol, diuretics like hydrochlorothiazide) can cause or worsen ED. If you're concerned that your blood pressure medication might be affecting your sexual health, it’s important to talk to your healthcare provider about adjusting your treatment or exploring other options.

If Viagra isn’t the right fit for you—whether due to concerns about side effects or interactions with your current medications—other treatment options are available. These include other PDE5 inhibitors, which work similarly to Viagra, though they may not ameliorate your concerns about Viagra since they work in a similar way. Your healthcare provider can help determine the best option for your individual situation. 

Here’s a quick overview of how other PDE5 medications compare to Viagra (sildenafil):

• Cialis (tadalafil) takes about 30 minutes to 2 hours to start working, but its effects can last up to 36 hours. This longer duration allows for more flexibility and less planning. It can also mildly lower blood pressure, particularly when used with blood pressure medications, though the reductions are usually small and not clinically significant.

• Vardenafil, which was previously available as brand name Levitra and Staxyn, kicks in within 30–60 minutes and lasts for about 4–6 hours. It’s also available as an orally disintegrating tablet, which can be conveniently taken without water. Like sildenafil, vardenafil may lower blood pressure, but only modestly.

• Stendra (avanafil) is known for its rapid onset—as little as 15 minutes. Like sildenafil and vardenafil, Stendra lasts 4–6 hours, making it a great option for spontaneity. But generic versions aren’t yet available, making it potentially more expensive. Also like the others, avanafil can have minimal effects on blood pressure. 

Some PDE5 inhibitors can also be found in other (non-pill) formulations. For example, Ro Sparks is a sublingual (read: dissolves under the tongue) treatment containing both sildenafil and tadalafil (the active ingredients in Viagra and Cialis, respectively). Another fast-acting, non-pill option? Ro’s Daily Rise Gummies, which feature 7 mg of tadalafil in each fruit-flavored gummy.  

In addition to medication, lifestyle changes can help improve erectile function. Regular exercise can boost circulation, lower blood pressure, and reduce ED symptoms. A healthy diet rich in fruits, vegetables, and whole grains also supports better blood flow and overall health. Managing stress and anxiety and getting enough quality sleep are essential too, as both mental and physical health play a role in sexual function.

If you’re struggling with ED, discussing your options with a healthcare provider can help you find the right treatment plan, whether that’s medication, lifestyle adjustments, or a combination.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

October 11, 2024

Written by

Patricia Weiser, PharmD

Fact checked by

Raagini Yedidi, MD

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About the medical reviewer

Raagini Yedidi, MD

Raagini Yedidi, MD, is an internal medicine resident and medical reviewer for Ro.