Key takeaways:
Cialis (tadalafil) is a prescription medication used to treat erectile dysfunction and symptoms of benign prostatic hyperplasia.
Common Cialis side effects include headache, upset stomach, and back pain. Low blood pressure can also happen, especially if you combine Cialis with other substances that lower your blood pressure.
Rare, but serious Cialis side effects include vision problems, sudden hearing loss, and erections that last longer than 4 hours (priapism). Stop taking Cialis and seek emergency medical care if any severe side effects happen.
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Cialis (tadalafil) is a prescription medication that treats erectile dysfunction (ED) and symptoms of benign prostatic hyperplasia (BPH). It’s part of a group of medications called phosphodiesterase 5 (PDE5) inhibitors.
Cialis works by increasing blood flow to the penis, making it easier to have an erection. It also increases blood flow to the prostate, reduces inflammation, and relaxes muscles in the urinary tract to help with BPH. Usually, Cialis is well tolerated. But knowing what side effects to watch for can help you get the most from your medication.
Here’s what you should know.
Cialis side effects at a glance
Below, we’ve listed common and rare, but serious Cialis side effects reported in clinical studies. But other side effects are possible. Reach out to your healthcare team about any severe or concerning side effects that occur while taking Cialis, even if they aren’t listed here.
Before starting Cialis, ask your prescriber or pharmacist if it interacts with your other medications. Some Cialis interactions can increase your risk of side effects.
Common or mild Cialis side effects include:
Headache
Heartburn
Upset stomach
Nausea
Flushing
Muscle aches
Back pain
Cold symptoms, including nasal congestion and cough
Diarrhea
Rare, but more serious Cialis side effects include:
Vision problems
Hearing loss
Priapism (prolonged or painful erections)
Low blood pressure when combined with other substances or medications that decrease blood pressure
Below, we’ll discuss seven Cialis side effects in greater detail and offer tips to help you manage them.
1. Headache
Headaches are one of the most common Cialis side effects. This is likely because of how Cialis works. It increases blood flow and enhances the effects of a chemical called nitric oxide. These actions are thought to trigger headaches, including migraines. People taking higher doses of Cialis are more likely to experience headaches.
If you experience headaches after taking Cialis, some tips to follow include:
Avoiding alcohol: Headaches are more likely if you drink alcohol while taking Cialis. Even just 1 or 2 drinks can also interfere with your body’s ability to maintain an erection.
Staying hydrated: Dehydration is an easily overlooked cause of headaches. If your pee is dark, it’s a sign to drink more water.
Taking an over-the-counter (OTC) pain reliever: Medications like Tylenol (acetaminophen) or Advil (ibuprofen) are usually safe to take with Cialis. But check with your prescriber or pharmacist first.
Cialis (tadalafil) vs. Viagra (sildenafil): See how these two compare to other similar medications for treating erectile dysfunction (ED).
As-needed vs. daily Cialis: You can take Cialis two ways — at least 30 minutes before sex or at the same time every day. Both approaches have their pros and cons.
Cialis tips: New to Cialis or just looking to get better results? Here are pharmacist-backed tips for how to take Cialis.
If your headaches continue or feel severe, talk with your prescriber. They may recommend a lower Cialis dose. If you’re taking Cialis as needed, switching to daily Cialis may be another option — side effects are less likely with this dosage schedule.
2. Upset stomach
You might have an upset stomach after taking Cialis. This is because Cialis increases blood flow to other areas of the body besides the penis, including the stomach. This increased blood flow can lead to stomach-related symptoms, such as heartburn, nausea, and indigestion.
If needed, some strategies to prevent or settle an upset stomach include:
Taking Cialis with food
Eating smaller, more frequent meals throughout the day
Limiting or staying away from spicy and fried foods, which can worsen stomach problems
Trying an acid reflux medication, such as Tums (calcium carbonate) or Pepcid AC (famotidine)
If stomach problems continue, let your prescriber know. They may suggest a lower Cialis dose or consider whether there’s something else going on.
3. Back pain
Back pain is another possible Cialis side effect. Muscle and limb pain can also happen, but they’re not as common.
Back and muscle pain may seem like odd side effects for ED medications. But Cialis blocks an enzyme (protein) that’s found in skeletal muscle. This can cause pain for some people.
Back pain from Cialis is usually mild and improves over time. Gentle stretching or a cold compress might help. For ongoing muscle pain, applying heat might be a better option. If needed, try an OTC pain reliever, but check with your healthcare team about your safest option first.
4. Low blood pressure
Cialis may slightly lower your blood pressure on its own. This isn’t usually a concerning side effect. But it’s a more serious issue if you combine Cialis with other substances that also lower your blood pressure. This includes blood pressure medications, nitroglycerin (Nitrostat, etc.) for chest pain, and alcohol.
It’s best to avoid combining Cialis with alcohol and other medications that lower blood pressure to avoid a potentially dangerous drop in blood pressure. If this happens, you may feel dizzy, weak, or even lose consciousness. Review your medication list with your prescriber before starting Cialis to make sure it’s a safe option for you.
5. Prolonged erection
In rare cases, Cialis can lead to a prolonged erection (priapism) that lasts longer than 4 hours.
Priapism is a medical emergency. If it isn’t treated, serious consequences, such as an inability to have an erection in the future, can happen. So call 911 or seek emergency care if your erection lasts longer than 4 hours while taking Cialis.
6. Vision problems
Cialis and other PDE5 inhibitors are linked to several types of vision problems. Researchers think blood flow changes in the eye may be to blame.
The most common visual side effects of Cialis include sensitivity to light and blue-tinted or hazy vision. These changes usually go away if Cialis is stopped.
In rare cases, more serious eye problems are possible. These include:
If you develop any trouble with your vision while taking Cialis, seek emergency medical care right away. If you’re living with a chronic eye issue, talk to your prescriber before starting Cialis — it may not be the safest option for you.
7. Hearing loss
In rare cases, hearing loss can occur after taking Cialis and other PDE5 inhibitors. This usually occurs within the first few days of taking the medication. Symptoms typically include loss of hearing in one or both ears. You may also feel dizzy or have tinnitus (ringing in the ears).
If you notice any of these symptoms, stop taking Cialis and seek emergency care.
Frequently asked questions
It’s best to avoid Cialis if you take medications that interact with it, such as nitrates. If you’re living with heart problems or an eye condition, Cialis may not be a safe option for you. You may also need a lower Cialis dose if you’re living with liver or kidney problems. The best way to protect your safety is to review your medication list and health history with your prescriber before starting Cialis.
Cialis doesn’t directly affect testosterone levels. It helps improve ED and BPH by increasing blood flow and relaxing muscles in the urinary tract. If you have concerns about your testosterone levels, talk with your healthcare team. They can determine if your levels are low and recommend treatment if needed.
The possible Cialis side effects are the same, whether you take it as needed or on a daily basis. Most side effects seem to be less common or severe with daily Cialis. But daily Cialis may increase your risk of certain infections. If you’re experiencing unpleasant side effects when taking Cialis as needed, talk to your prescriber about trying it daily to see if that helps.
It’s best to avoid Cialis if you take medications that interact with it, such as nitrates. If you’re living with heart problems or an eye condition, Cialis may not be a safe option for you. You may also need a lower Cialis dose if you’re living with liver or kidney problems. The best way to protect your safety is to review your medication list and health history with your prescriber before starting Cialis.
Cialis doesn’t directly affect testosterone levels. It helps improve ED and BPH by increasing blood flow and relaxing muscles in the urinary tract. If you have concerns about your testosterone levels, talk with your healthcare team. They can determine if your levels are low and recommend treatment if needed.
The possible Cialis side effects are the same, whether you take it as needed or on a daily basis. Most side effects seem to be less common or severe with daily Cialis. But daily Cialis may increase your risk of certain infections. If you’re experiencing unpleasant side effects when taking Cialis as needed, talk to your prescriber about trying it daily to see if that helps.
The bottom line
Cialis (tadalafil) is a medication for erectile dysfunction and benign prostatic hyperplasia. Common Cialis side effects include headache, upset stomach, and back pain. Low blood pressure is also possible, especially if you combine Cialis with alcohol or other medications that lower your blood pressure.
Rare, but serious Cialis side effects include vision issues, sudden hearing loss, and erections that last for more than 4 hours. Seek emergency care if serious side effects occur.
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References
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