Does Cialis lower blood pressure?

Many men are reluctant to talk to their healthcare providers about their erectile dysfunction (ED), making it difficult to know just how many suffer from this condition. The best estimate is that over 50% of men between 40 and 70 in the United States have ED (Sooriyamoorthy, 2022). ED can affect the quality of life for not only the person experiencing it but their partner as well. The good news is ED is often easily treatable with a prescription drug like tadalafil (Cialis), so it’s worth discussing with your provider. 

Reading the warning labels on prescription drugs can understandably make people nervous. You may have read some warnings about Cialis and blood pressure. Keep reading to learn more about Cialis, whether it lowers blood pressure, and other potential side effects.

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The Food and Drug Administration (FDA) approves Cialis for use in adult males. It is approved to treat erectile dysfunction (the inability to get or keep an erection long enough for sexual intercourse). It is also approved to reduce signs and symptoms of benign prostatic hyperplasia (BPH), an enlarged prostate. Cialis is also approved in men experiencing both conditions at the same time. 

The active ingredient in Cialis is tadalafil. It belongs to a class of medications known as phosphodiesterase-5 enzyme inhibitors or PDE-5 inhibitors for short. Other medications in this class used to treat ED include (Dhaliwal, 2022): 

• Viagra (sildenafil)

• Levitra (vardenafil)

• Stendra (avanafil) 

You may have heard that PDE-5 inhibitors increase blood flow to the penis, but they can also increase blood flow elsewhere in the body. Tadalafil is the active ingredient in Cialis, but it is also the active ingredient in two other drugs: Adcirca and Alyq. These medications are FDA-approved to treat pulmonary hypertension, which is high blood pressure in the lungs. But pulmonary hypertension is not the same as systemic hypertension (high blood pressure) (Dhaliwal, 2022). 

Blood pressure is a measure of the force that your heart uses to pump blood around your body. Healthcare providers usually consider normal blood pressure to be less than 120/80 mmHg. Low blood pressure (hypotension), which may cause symptoms of dizziness or fainting, is when your reading is less than 90/60 mmHg. 

PDE-5 inhibitors like Cialis do not typically cause major changes in blood pressure. However, taking Cialis with certain other medications, such as nitroglycerin, can cause your blood pressure to drop dangerously low. In fact, this drug interaction can be life-threatening and is discussed in further detail below in this article. 

Cialis works by relaxing smooth muscle cells in blood vessels, which widens them and increases blood flow. It does this by inhibiting or blocking an enzyme known as PDE-5. This enzyme breaks down the chemical pathway that causes smooth muscle cell relaxation. Blocking this process results in long-lasting smooth muscle cell relaxation. In the penis, the increase in blood flow helps you achieve and maintain an erection (Huang, 2013). Cialis doesn’t give you an automatic erection—you will still need sexual stimulation. 

Even though Cialis relaxes smooth muscle cells, it does not seem to affect blood pressure to a significant extent in people with no other health concerns. During clinical trials of the drug, researchers measured the blood pressures of people taking Cialis 20 mg and those taking a placebo. They measured blood pressure while people were both standing up and lying down. On average, decreases in blood pressure were minimal (a drop of 0.2/4.6 mmHg while standing up and 1.6/0.8 mmHg while lying down). No participants in the clinical trial had a major drop in blood pressure (DailyMed, 2022).

Note that Cialis is different from the other PDE-5 inhibitors in a few ways. Depending on your healthcare professional’s instructions, you can either take Cialis as needed before sexual activity or at a low dose once daily. The amount of time Cialis stays in your body is longer than similar drugs in its class, making it effective for up to 36 hours after you’ve taken a dose (DailyMed, 2022). Both of these features make it a convenient option since it allows stimulation and intercourse to happen more spontaneously.  

Like all medications, Cialis comes with a risk of side effects. Knowing side effects ahead of time will help you know what to look for and expect when taking it, and whether it’s the right drug for you.

Common side effects of Cialis include (DailyMed, 2022):

• Headache

• Indigestion, upset stomach, or heartburn

• Back pain

• Muscle pain

• Nasal congestion

• Upper respiratory tract infections

• Flushing, including facial flushing (when your skin becomes hot and red)

• Pain in your arms or legs

• Dizziness

• Cough

• Changes in color vision presenting as a slight blue tinge around objects 

While rare, people taking Cialis might have serious side effects. The following is not a complete list of possible side effects. Be sure to call your healthcare provider or seek medical attention right away if you experience (Dhaliwal, 2022):

• A painless decrease in vision in one eye

• Hearing loss

• Priapism, a painful, prolonged erection lasting 4 hours or longer

• Skin blistering, a severe rash, or other signs of an allergic reaction

Skin cancer and prostate cancer have also been reported in people who took Cialis. In addition, because of an increased risk of cardiovascular events during or after sexual activity, such as heart attack and stroke, Cialis isn’t typically recommended for people with significant heart problems or cardiovascular disease. Your heart needs to be healthy enough for sex before considering Cialis for ED (DailyMed, 2022).

Cialis isn’t safe for everyone. Before prescribing Cialis, your healthcare provider will go over your medical history to determine if the drug is right for you. 

You should not take Cialis with nitrate drugs because an unsafe and even life-threatening drop in blood pressure could occur. Nitrates are used to prevent or treat angina, a type of chest pain. Examples of nitrates are nitroglycerin tablets (NitroStat) or patches, isosorbide mononitrate, and isosorbide dinitrate (DailyMed, 2022).

Healthcare providers usually don’t prescribe Cialis to people also taking a nitrate drug. To be safe, nitroglycerin should be taken at least 48 hours after a dose of Cialis. If you develop angina symptoms but have already taken Cialis in the past two days, you should not take a nitrate drug. Instead, seek emergency medical care and tell the staff you’ve recently taken Cialis.

In addition, Cialis should not be taken with a guanylate cyclase stimulator drug like Adempas (riociguat) or Verquvo (vericiguat). Taking Cialis with either of these medications may also cause extremely low blood pressure (DailyMed, 2022).

People with the following medical conditions were not included in clinical trials for Cialis, so this drug is generally not recommended for people with (DailyMed, 2022):

• Recent stroke or heart attack (in the last 90 days)

• Chest pain during sexual activity

• Heart failure

• Uncontrolled arrhythmias, low blood pressure (hypotension), or uncontrolled high blood pressure (hypertension)

If Cialis isn’t safe for you, your healthcare provider can offer personalized medical advice on other ED treatment options.

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How we reviewed this article

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.

Current version

December 12, 2022

Written by

Patricia Weiser, PharmD

Fact checked by

Chimene Richa, MD

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About the medical reviewer

Chimene Richa, MD

Dr. Richa is a board-certified Ophthalmologist and medical writer for Ro.