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Cialis vs Viagra: Which Is More Effective?

Cialis vs Viagra: Which Is More Effective?

Stefano Mirabello NowPatientGreen tick
Medically reviewed by Stefano Mirabello, B.Pharm
Written by

Created
March 28, 2025 (Current Version)

Viagra is the most famous erectile dysfunction medication available but there are alternatives, like Cialis.

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Viagra and Cialis work in a similar way but they do have differences. You may find one of them works better for you. But which one, Cialis or Viagra?

To help you decide which of these meds is right for you, we’ll explain how Viagra and Cialis are different. We’ll detail what they do, how they do it, any side effects, what dosage to take, and how you buy them.

What are Cialis and viagra?

Cialis and Viagra are medications used to treat erectile dysfunction (ED), which is when a man can’t get or keep an erection that’s hard enough for sex.

They’re both swallowed as a pill before you plan to have sex, and they both improve the flow of blood to your penis to make it easier for you to get an erection.

Neither medication will put you in the mood for sex or increase your sexual desire (libido), and they won’t give you an automatic erection. They help turn your desire into a lasting erection, and they’re amongst the most effective treatments for ED.

Viagra and Cialis also come in cheaper, equally as effective, generic versions too – sildenafil (Viagra) and tadalafil (Cialis).

How do Cialis and viagra work?

Both medications belong to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors. They improve the flow of blood to your penis, making it easier for it to fill with blood, giving you an erection.

Viagra and Cialis work by increasing the amount of a substance in your body called cGMP (cyclic guanosine monophosphate). They do this by blocking the PDE5 enzymes that break down cGMP, causing the substance to build up in your blood. This is good, as cGMP relaxes the muscle tissue in your arteries and penis. This, in turn, causes them to relax and widen, improving the flow of blood to your penis. It will then fill with blood easier, which helps you to get an erection.

What’s the main difference between viagra and Cialis?

One of the main differences between Viagra and Cialis is that they are manufactured by different pharmaceutical companies. Viagra is made by Pfizer and Cialis is made by Eli Lilly.

Although both Viagra and Cialis work in the same way, there are some differences between how fast they work and how long they last for.

For most men, Viagra works a little quicker than Cialis. Viagra takes between 30 minutes and one hour to work, whereas Cialis takes a little longer, usually between one to two hours.

The biggest difference is how long they last for. Viagra lasts around four hours for most men, and you may be able to get more than one erection in this time. Cialis lasts for longer, however. It can be effective for up to 36 hours. This has led some people to call Cialis the “weekend pill”, as you can take it at the start of the weekend, and you may reap the benefits until Sunday.

How do you take viagra and Cialis?

Both drugs are usually taken as pills that are swallowed with water.

Rather than being taken on a regular basis, you take Viagra between 30 minutes and one hour before sex. You take Cialis between one to two hours before, although Cialis can be taken earlier as it works for much longer. You can also take a lower strength version of Cialis on a daily basis for certain conditions.

If you take Viagra when you’re eating, it can slow down how quickly it’s absorbed and how fast it works, particularly if you eat a large, high-fat meal. Food won’t affect how quickly Cialis works though.

What dosages do viagra and Cialis come in?

Viagra comes in three different dosages: 25 mg, 50 mg, and 100 mg. The usual starting dosage is 50 mg.

Cialis comes in two dosages: 10 mg and 20 mg. The usual starting dosage is 10 mg. Cialis also comes in 2.5 mg and 5 mg strengths pill that can be taken on a daily basis.

How do you buy viagra and Cialis?

In the US, both Viagra and Cialis are prescription drugs. You have to get a prescription from a licensed healthcare professional, usually a doctor. Some online retailers are also licensed to make prescriptions, like us at FROM MARS. You can have an online consultation with one of our doctors, and if approved, we’ll ship your medication to you for free. This is a fast, easy, and safe way to get the meds you need.

What side effects do Viagra and Cialis cause?

As Viagra and Cialis affect your body in broadly the same way, they can cause similar side effects, particularly the more common ones. These include headaches, nausea and stomach upsets, dizziness, facial flushing, and muscle pain. Viagra more often causes sight disturbances than Cialis though, like blurring and having color tints to your vision.

Side effects may be shorter-lasting with Viagra, as it doesn’t stay in your system for as long as Cialis does.

How much do Cialis and Viagra cost?

The cost of Viagra and Cialis will vary depending on where you buy them. Cialis tends to be slightly more expensive than Viagra, as it’s longer-lasting.

You can buy generic versions of these drugs too. Generic drugs are copies of branded medications, like Viagra and Cialis, made by different manufacturers. Generic drugs contain the same ingredients at the same strengths as the branded ones, so work just the same. They tend to be cheaper too.

Cialis vs viagra – frequently asked questions:

Can you mix viagra with Cialis?

No. Don’t take Viagra and Cialis together. As both drugs work in a similar way and contain similar ingredients, you risk increasing the likelihood of getting side effects, including the more serious ones.

Can you take viagra after Cialis?

Don’t take Viagra and Cialis together, as you risk making their side effects more likely. You should only take one after the other once the first drug is out of your system. Wait at least 24 hours after Viagra, and at least 36 hours after Cialis.

Can you take viagra or Cialis with alcohol?

Viagra and Cialis can be taken with moderate amounts of alcohol. Drinking excessive amounts of alcohol can make some side effects more likely. Alcohol can make it harder to get an erection, so it may counter the effects of Viagra or Cialis.

So which ED medication is right for me?

This depends on you. As Cialis works for longer, it can offer you a certain degree of spontaneity. You could feel its effects for up to 36 hours giving you more freedom over when you have sex and how many times.

But if these drugs do give you side effects, Viagra may be a better option, as it’s shorter lasting.

If you have ED and you want to try Cialis or Viagra, then you can always try both (although not at the same time). You can see which drug works best for you and make an informed decision of which is the right one for your needs.

Sources

Medical Disclaimer

NowPatient has taken all reasonable steps to ensure that all material is factually accurate, complete, and current. However, the knowledge and experience of a qualified healthcare professional should always be sought after instead of using the information on this page. Before taking any drug, you should always speak to your doctor or another qualified healthcare provider.

The information provided here about medications is subject to change and is not meant to include all uses, precautions, warnings, directions, drug interactions, allergic reactions, or negative effects. The absence of warnings or other information for a particular medication does not imply that the medication or medication combination is appropriate for all patients or for all possible purposes.

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