You shouldn’t take Cialis (tadalafil) and Viagra (sildenafil citrate) together to help with treating erectile dysfunction (ED).

It’s also typically recommended that you take one or the other shortly before sex, but not daily or on a regular schedule. These ED medications only work if you’re already aroused.

Taking both Cialis and Viagra can also increase your risk of side effects, such as low blood pressure.

And if you feel like you need to take a second ED medication because the first one isn’t helping, you may need to see your doctor to diagnose any underlying issues that may be causing your ED.

Let’s look into why taking both Cialis and Viagra won’t make a big difference in how easily you can get an erection, when you should seek treatment for ED, and what other home remedies for ED you can try.

Cialis and Viagra are both phosphodiesterase type 5 (PDE5) inhibitors. PDE5 is an important enzyme involved in erections that’s one of the biggest culprits behind ED.

Here’s how Cialis and Viagra work:

  • When your penis nerves are stimulated, you get an erection. When this happens, muscles that surround two cylinder-shaped pieces of tissue in your penis, called the corpora cavernosa, relax and fill with blood.
  • When you have ED, nerves aren’t communicating between your brain and your penis to help make this process happen, so blood doesn’t flow properly into your penis.
  • Viagra and Cialis block PDE5 and help relax your blood vessel walls. This makes it easier for blood to flow into your penis tissues and give you an erection.

So keeping in mind how Cialis and Viagra work, here’s why it’s not necessary to take them together:

  • Both Cialis and Viagra work on the same mechanism of arousal and erection. Taking both is basically the equivalent of increasing your overall dose of PDE5 inhibitor. Increasing your dose of any medication without approval from your doctor can be dangerous. Your body may not respond the same way to a higher dose of a medication.
  • You need to be sexually aroused for PDE5 inhibitors to work. Neither Cialis nor Viagra cause erections on their own. They simply help your natural erection processes work more easily. Taking them every day won’t help if you’re not aroused.
  • Cialis is designed to last much longer than Viagra. Viagra typically lasts about 4 hours after you take it. Cialis can last up to 36 hours after you take it. If you’re already taking Cialis, Viagra may not have any additional effects because Cialis is still functioning in your body.

The dosage of each medication makes it unnecessary to take them together, too.

Cialis is usually given in a low-dose form of 2.5 milligrams (mg), which makes it safe to take every day on its own. The low dose also makes it less likely that you’ll experience side effects.

Viagra is given in much higher doses — the lowest available dose is 25 mg. It also needs to be taken 30 minutes or more before sex because the ingredients work much more quickly at such high concentrations.

Cialis and Viagra don’t have any dangerous interactions with each other because they’re the same type of medication.

But increasing your dose of a PDE5 inhibitor can increase your risk of side effects that are associated with these kinds of ED medications.

Here are some of the more common side effects of Viagra and Cialis:

See your doctor if you notice any of these side effects, especially if they last for a few hours after the medication has worn off or if they linger for more than a day afterward.

Cialis can cause your blood pressure to drop dangerously low when taken together with nitroglycerin (Nitrostat). Don’t use Cialis if you’re already taking nitroglycerin for blood pressure.

Seek emergency medical treatment if you notice any of the following side effects:

  • sudden chest pains during or after sex
  • an erection that lasts 4 hours or more (priapism)
  • having trouble seeing or hearing
  • skin reactions like hives
  • face or eye swelling
  • unexplained seizures
Healthline

If PDE5 inhibitors aren’t working for you, there are some other ED treatments your doctor might recommend:

Your doctor may also recommend one of the following experimental treatments:

Here are some other treatments you can try to help make your ED medication more effective or as alternatives to medication:

  • Limit alcohol. Drinking less alcohol can improve blood flow.
  • Quit smoking. Smoking can inhibit blood flow.
  • Maintain a healthy weight. Exercise and a healthy diet will keep your weight down and improve your blood flow.
  • Get a good night’s sleep. This will reduce stress damage to tissues that can make ED worse.

Don’t buy Cialis or Viagra without a prescription. Only your doctor can perform the examinations necessary to make sure these medications and their dosage are safe for you.

Don’t take Cialis and Viagra together. Not only will combining them not improve ED symptoms, it can be dangerous.

Talk to your doctor about any concerns you have about your ED and its causes. In some cases, incorporating both medication and lifestyle changes is the best way to help improve ED symptoms.