Why these pills cause headaches
Viagra and Cialis are brand-name erectile dysfunction pills. Viagra, made by Pfizer, contains sildenafil. Cialis, made by Eli Lilly, contains tadalafil. Both belong to a class called PDE5 inhibitors.
They work by blocking an enzyme called PDE5. That lets a chemical called nitric oxide relax the smooth muscle in blood vessels, so arteries widen and blood flows in. In the penis, that means a firmer erection.
The problem is that PDE5 is not only in the penis. It is also in blood vessels in the head, face, and nose. When those widen, pressure changes around the brain and sinuses can trigger a headache, a flushed face, or a stuffy nose. The headache is a direct result of how the drug works, not an allergy.
How common it is
Headache is the number one reported side effect. In the clinical trials listed on the Viagra label, about 16 percent of men taking sildenafil reported headache, compared with 4 percent on placebo. Higher doses caused more headaches.
For Cialis, the label reports headache in about 11 to 15 percent of men on as-needed doses, and about 3 to 6 percent on the low daily dose. Vardenafil (Levitra) and avanafil (Stendra) have similar rates.
Most of these headaches are mild to moderate and last a few hours. Fewer than 2 percent of men in the trials stopped the drug because of headache.
What the headache feels like
Men usually describe a dull, throbbing pressure across the forehead or temples, sometimes with a flushed, warm face. It typically starts within an hour of taking the pill and fades as the drug wears off. For sildenafil that is roughly 4 to 6 hours; tadalafil lasts longer, up to 36 hours, so a headache may linger.
Alcohol makes it worse, because alcohol also widens blood vessels and causes dehydration. Dehydration on its own is one of the biggest triggers.
Ways to prevent it
Lower the dose. Many men take more than they need. Sildenafil comes in 25, 50, and 100 mg; tadalafil in 2.5, 5, 10, and 20 mg. The lowest dose that works for you will usually cause the least headache. Ask your prescriber before changing it.
Drink water before and after. Being well hydrated blunts the vessel-widening effect on the head. Skip or limit alcohol on nights you use the pill.
Consider switching medicines. Some men get headaches on sildenafil but not tadalafil, or the reverse. Daily low-dose tadalafil (2.5 to 5 mg) keeps a steady, low level in the blood and causes fewer headaches than a single large dose.
Do not take the pill on an empty stomach if that bothers you, and avoid grapefruit juice, which can raise drug levels and worsen side effects.
Treating a headache once it starts
Over-the-counter pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil) are generally safe to take with sildenafil or tadalafil and work well for this kind of headache. Take them at the first sign rather than waiting.
Rest in a cool, dim room, drink a glass of water, and put a cool cloth on your forehead. A small amount of caffeine, which narrows blood vessels slightly, helps some men.
Never combine ED pills with nitrate medicines for chest pain, such as nitroglycerin, and be careful with alpha-blockers. These can cause a dangerous drop in blood pressure that may feel like dizziness or a severe headache. Tell your prescriber about every medicine you take.
When a headache is a warning sign
A typical PDE5 headache is uncomfortable but not dangerous. Get emergency help for a sudden, severe 'worst headache of my life,' a headache with vision loss or seeing a blue tint, sudden hearing loss, chest pain, fainting, or an erection lasting more than four hours.
If headaches happen every time and ruin the experience even at a low dose, talk to your prescriber. There may be another cause of your ED, such as low testosterone or a blood-flow problem, that calls for a different approach.
How Zen IV Spa can help
Zen IV Spa's ED program is $129 and uses generic sildenafil or tadalafil, the same active ingredients found in Viagra and Cialis. Our medical team starts with a free video visit, can draw labs at your home in New York or New Jersey, and will adjust your dose or switch medicines to find the option that works with the fewest side effects. Medicines ship to your door. Learn more at /sexual-wellness/.
Common Questions
Why does Viagra give me a headache?+
Sildenafil widens blood vessels throughout the body, including in the head. That pressure change triggers the headache. It is a known effect, not an allergy.
Which causes fewer headaches, Viagra or Cialis?+
Rates are similar for as-needed doses. Low daily-dose tadalafil tends to cause fewer headaches than a single large dose of either drug.
Can I take Tylenol or Advil with Viagra?+
Yes. Neither interacts with sildenafil or tadalafil, and both work well for this type of headache.
How long does a Viagra headache last?+
Usually a few hours, fading as the drug clears. Tadalafil lasts longer, so its headache may linger.
Does a lower dose reduce headaches?+
Yes. In trials, headache rates rose with dose. The lowest effective dose is the best defense.
When should I worry about a headache after an ED pill?+
If it is sudden and severe, or comes with vision or hearing loss, chest pain, or fainting, seek emergency care.
Sources: FDA prescribing information for Viagra (sildenafil) and Cialis (tadalafil); American Urological Association erectile dysfunction guideline (2018); Mayo Clinic guidance on erectile dysfunction medications.
All treatments are medical services. Every guest is screened, and every treatment is prescribed by a licensed provider. Nothing on this page is medical advice for you personally, and the opinions summarized here belong to the doctors named, not to Zen IV Spa. Talk to a provider before starting or stopping anything.
