Does Viagra or Cialis cause headaches?

Headaches can be a common side effect of erectile dysfunction (ED) medications, such as Viagra (sildenafil) and Cialis (tadalafil). In general, the higher the dose, the more likely headaches and other side effects are to occur while taking these ED treatments. Luckily though, Viagra and Cialis headaches are treatable and typically short-lived. 

Here, we explain how and why Viagra and Cialis can cause headaches and offer expert-backed tips to treat and prevent the side effect, so you can continue to reap the rewards of ED meds without a throbbing head.  

First, a little erection 101: When you see, touch, or think about something that arouses you, your brain sends signals to your penis and certain chemicals get to work relaxing the erectile tissues. This allows blood to rush into the penis, where it gets trapped and, in turn, you get hard. After you orgasm (or are no longer aroused), an enzyme known as phosphodiesterase-5 (PDE5) breaks down those chemicals, which allows blood to exit the penis, allowing the penis to return to its normal flaccid state. 

Viagra works by blocking PDE5, inhibiting the enzyme from breaking down the erection-causing chemicals. As a result, tissues in the penis stay relaxed, blood vessels widen, and blood continues to flow more freely into the penis. Essentially, the little blue pill encourages the penis to remain engorged with blood (aka hard) when you’re already sexually aroused. 

Like Viagra, Cialis is a PDE5 inhibitor that also treats the symptoms of ED by blocking the PDE5 enzyme. In other words, they’re part of the same drug class. So, while there are a few stand-out differences between Cialis and Viagra (e.g. how long they last, how often they can be taken, available strengths), it’s not all that surprising that they both have similar side effects, including—yup—headaches.

Headaches are the most common side effect associated with Viagra with up to 28% of patients who are prescribed the medication experiencing headaches, especially at higher doses.

While the correlation between Viagra (and PDE5 inhibitors in general) and headaches isn’t completely understood, the side effect might be a result of the medication’s ability to widen blood vessels. As mentioned above, Viagra (and Cialis) dilates blood vessels, which increases blood flow to your penis. By causing this vasodilation, the ED meds can also boost blood flow to other areas of your body, such as your brain. These changes in blood flow might be to blame for the development of a Viagra-related headache. 

It’s also worth noting that there also seems to be a relationship to dosage. In one study, for example, researchers noted that higher doses of Viagra present a higher risk of developing headaches.

Cialis can cause headaches for the same reasons that Viagra can lead to the side effect. Clinical trials found that between 11% and 15% of men reported experiencing headaches after taking Cialis. In other words, headaches are one of the more common side effects of the ED drug. But like Viagra headaches, Cialis headaches tend to go away after about a week of treatment for many people.

The last thing you want is your dose of Viagra or Cialis to be accompanied by pain or discomfort—nothing dampens the mood quite like a pounding headache. Bedroom activities aside, a headache can also make it difficult to go about your daily life, from working at your full capacity to getting a good night’s sleep. The good news: There are a handful of ways to address Viagra and Cialis headaches. 

Consider a lower dosage 

Studies show that men who take lower-dose daily Cialis typically have fewer or milder side effects than those who take higher doses, and the same is true for lower doses of Viagra. (Doses of 100 mg or higher of the latter have been associated with greater side effects). If you’re experiencing headaches on a higher dosage, talk to your healthcare provider about potentially trying a lower dosage that could still be effective in treating your ED.

Switch to a different ED medication 

Switching brands of ED medications probably won’t cure your headaches entirely since this is a common side effect with all types of PDE5 inhibitors. Alternatively, ask your provider about avanafil (Stendra), a new ED treatment that’s been shown to have the lowest rate of headaches and other symptoms associated with ED meds, such as flushed cheeks and dizziness.

Stay hydrated 

Dehydration is a common cause of headaches in and of itself, and physical activities, such as sex, are more likely to leave you feeling dehydrated, as they can cause you to sweat and lose fluid in your body. (After all, intercourse can be quite the workout.) But breaking a sweat in the bedroom isn’t the only way you might experience dehydration. Drinking alcohol and caffeine can also be to blame; that’s because both beverages are diuretics, meaning they can make you have to urinate (i.e. lose fluid) more often than usual. 

The fix? Stay hydrated. Avoid drinking high amounts of alcohol and caffeine prior to taking your pill and be sure to drink lots of water before, after, and while the medication is in your system. You also might want to consider eating a light meal or snack when you take Viagra or Cialis—just be sure to steer clear of high fat foods, as they can delay absorption and, in turn, efficacies of certain PDE5 inhibitors.

Take an over-the-counter painkiller 

While it’s always best to talk to your healthcare provider before popping any pills, taking acetaminophen (Tylenol) or ibuprofen (Advil) to treat a temporary headache from Viagra or Cialis is most probably a safe bet. When taken at the recommended dose, both of these over-the-counter meds don’t interact with Viagra or Cialis.

Treat it as you would any other headache 

None of the above doing the trick? Nurse your Viagra or Cialis headache like you would any other: lie down in a dark room, place a cool compress over your eyes and forehead, massage your temples and/or neck, or take a hot shower.  

Headaches are a common side effect of ED medications such as Viagra and Cialis, though they tend to be mild and transient. Still, talk to your ED practitioner if your headaches become unbearable (think: negatively impacting your quality of life). No one should have to live (or have sex) in pain.

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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

April 30, 2024

Written by

Amelia Willson

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.