How to Take Cialis: 7 Tips to Get the Best Results and Avoid Side Effects

When it comes to medications for erectile dysfunction (ED), Cialis (tadalafil) is becoming more and more popular. Just like its well-known cousin Viagra (sildenafil), it comes as a tablet you take by mouth. But it lasts longer compared to other ED treatments.

Here, we’ll tell you what you need to know about Cialis — including how it works, how long it lasts, and potential side effects. We’ll also provide tips on how to use it safely.

What is Cialis, and how does it work to treat erectile dysfunction?

ED often happens when there isn’t enough blood flow to the penis, making it difficult to get or maintain an erection. This can be a result of a medical problem, medication, emotional distress, or some other factor. Your prescriber can help determine the cause and whether ED medication might be right for you.

Like Viagra, Cialis is a phosphodiesterase 5 (PDE5) inhibitor. It helps relax certain muscles and arteries inside the penis. When you’re sexually aroused, this increases blood flow to the penis and helps it fill with blood, leading to an erection.

Good to know: Cialis only works if you’re sexually aroused. If you’re not aroused, you won’t be able to get an erection.

7 tips for taking Cialis for maximum effect

Many people benefit from Cialis. But knowing how to get the maximum effect from it can enhance your overall experience. Here are a few tips for taking Cialis safely and effectively.

1. Cialis starts to work in about 30 minutes

So, how long does it take for Cialis to work? You might start to feel the effects of Cialis within 30 minutes. It’s recommended to take it at least 30 minutes before sex as a result. But know that it can take up to 2 hours for the full effects to kick in.

Studies also show that Cialis is not affected by the timing of meals. In other words, you can take Cialis with or without food — it won’t affect how fast it works.

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By comparison, Viagra also begins to work within 30 minutes. But its maximum effects usually set in after about 45 minutes to 1 hour. Other PDE5 inhibitors start working even faster. Vardenafil can start working in about 15 minutes, and avanafil (Stendra) starts working in under 15 minutes. Similarly to Viagra, their maximum effects also tend to appear in under an hour.

2. Cialis can last for up to 36 hours

The effects of Cialis last longer than the effects of Viagra. Cialis can last up to 36 hours. Viagra usually lasts for up to 5 hours.

But don’t be alarmed. That doesn’t mean every time you take Cialis, you’ll have an erection lasting a full day and a half. Instead, Cialis can help you achieve an erection throughout those 36 hours. How long Cialis lasts is a reason why some people prefer it over other ED medications; it allows for more spontaneous sexual activity.

If your erection lasts longer than 4 hours, even if it’s not painful, that’s considered a medical emergency. Call 911 or go to the nearest ER if you experience a prolonged erection.

3. Follow safe, recommended Cialis doses

There are two ways to take Cialis for ED:

1. Take a higher-dose tablet on an as-needed basis — at least 30 minutes before you plan to have sex.

2. Take a lower-dose tablet at the same time every day, even if you don’t plan on having sex that day.

EXPERT PICKS: WHAT TO READ NEXT

• Cialis (tadalafil) vs. Viagra (sildenafil): See how the two compare 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 side effects: Cialis is usually well tolerated. But it can occasionally cause side effects, including serious ones in rare cases.

The 10 mg tablet is usually recommended for as-needed use, though some people with ED might find that a lower (5 mg) or higher (20 mg) dose works better for them. The 2.5 mg and 5 mg tablets are more common choices for daily, scheduled doses.

According to several studies, there’s no difference in how well Cialis works or side effects between these two methods. However, daily Cialis isn’t recommended if you have severe kidney problems.

Keep in mind: With both methods, know that finding the right dose might take some trial and error. Make sure to tell your prescriber if your Cialis dose isn’t effective enough for you or if you’re having side effects. Your prescriber might increase or decrease your dose, or they might switch you to a different ED medication altogether.

4. You generally can’t make Cialis work faster

If you take Cialis as needed, be sure to give yourself plenty of time before sex. It can take about 2 hours for Cialis’ maximum effects to kick in. You can’t make it work faster after you’ve taken a dose.

If as-needed doses aren't working for you, your prescriber might want you to take a lower-dose tablet on a daily basis instead. This would be better if you prefer to be more spontaneous, too. If so, be sure to take it at the same time every day — no matter when you plan on having sex.

Whichever way you take Cialis, don’t take more than one dose per day. This helps prevent unnecessary risk and side effects.

5. Watch out for interactions with other medications

Combining ED medications like Cialis with high blood pressure medications can cause blood pressure that’s too low. One of Cialis’ side effects is lower blood pressure, so this can be a problem when paired with other blood pressure-lowering medications.

This is especially true when Cialis is paired with a nitrate medication. You should avoid this combination since these medications have a high risk of causing dangerously low blood pressure. Some include:

• Nitroglycerin (Nitrostat)

• Isosorbide mononitrate (Monoket)

• Isosorbide dinitrate (Isordil)

Other medications and foods can also interact with Cialis. They may lead to additional side effects. These include:

• Alpha blockers such as tamsulosin (Flomax)

• Riociguat (Adempas)

• Oral antifungal medications such as ketoconazole

• Antibiotics such as erythromycin (Ery-Tab)

• Grapefruit

• Alcohol

• Other PDE5 inhibitors

It’s always a good idea for your pharmacist and all prescribers to have an up-to-date list of all the medications and supplements you take. That way, they can minimize any interactions.

6. There are ways to manage Cialis side effects

Some of the more common Cialis side effects include:

• Headache

• Indigestion

• Back pain

• Muscle pain

• Nasal congestion

• Flushing

Side effects can slightly differ if you’re taking Cialis daily. In addition to what’s mentioned above, these side effects are more likely to occur with daily use:

• Upper respiratory infections

• Stomach bug

• Diarrhea

• Cough

• Urinary tract infections

• Acid reflux

• Abdominal pain

These side effects are usually mild and go away on their own. But if they don’t, you can usually treat them at home. For example, headaches can often be managed by drinking more water or taking an over-the-counter (OTC) pain reliever, such as acetaminophen (Tylenol). For indigestion and acid reflux, OTC antacids like Tums (calcium carbonate) can help.

If these side effects are still bothering you despite your best efforts to treat them, talk to your prescriber. They might lower your dose or explore other options for treating your ED.

Rare but serious side effects of Cialis may include:

• Erection lasting longer than 4 hours

• Sudden hearing loss

• Sudden vision loss

If any of these happen to you, stop taking Cialis and go to the nearest ER right away.

7. You can save money on Cialis

There are ways to save on Cialis, which is available as both a generic- and brand-name medication.

• Save with GoodRx: GoodRx can help you save over 80% off the average retail price of the generic version. Generic Cialis’ price at certain pharmacies is as low as $10.80 for 30 tablets with a free GoodRx discount. An equivalent dose of the brand-name product may cost as little as $292.62 with a free GoodRx discount.

• Save with a patient assistance program: If you’re uninsured or underinsured, you may be eligible for Cialis’ patient assistance program, which offers the medication free of charge.

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Written by:

Mae-Mae Han, PharmD Candidate

Mae-Mae Han, a PharmD Candidate at Butler University, has worked as a pharmacy intern in a community pharmacy for 3 years. She’s also a member of the Rho Chi pharmacy honor society and Phi Delta Chi professional pharmacy fraternity.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

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