All About Viagra’s Dosage

Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour before sexual activity.

The active ingredient in Viagra is sildenafil. (An active ingredient is what makes a drug work.)
Viagra belongs to a group of drugs called phosphodiesterase 5 (PDE5) inhibitors.

This article describes the dosage of Viagra, as well as its strengths and how to take it. To learn more about Viagra, see this in-depth article.

This section covers common questions about the dosage of Viagra.

What is Viagra’s form?

You may have heard Viagra described as the “little blue pill.” Viagra comes as a tablet that you swallow. It’s a blue tablet that has a rounded diamond shape.

What strengths does Viagra come in?

Viagra is available in three strengths: 25 milligrams (mg), 50 mg, and 100 mg.

What are the typical dosages of Viagra?

Typically, your doctor will start you on the recommended dosage. Then they’ll adjust your dosage over time to reach the right amount for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The information below describes dosages that are commonly used or recommended. But be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosage for erectile dysfunction

The recommended dosage of Viagra for erectile dysfunction (ED) is 50 mg, taken as needed about 1 hour before sexual activity. You can take it 30 minutes to 4 hours before sexual activity. And you shouldn’t take more than one dose per day.

After you try the 50-mg dose, you can let your doctor know how your body responded. This includes whether your erectile function improved or if you had any side effects.

Depending on how Viagra worked, your doctor may suggest decreasing your dose to 25 mg or increasing it to 100 mg. Or they may have you continue taking the 50-mg dose.

You’ll continue to take Viagra only as needed. The maximum dosage is once per day.

That said, the drug isn’t meant for daily dosing. If you’re interested in a once-daily treatment for ED, such as tadalafil (Cialis), talk with your doctor.

Maximum Viagra dosage

For most people, the maximum recommended dosage of Viagra is 100 mg once per day.

This dosage may be too high for people who have certain medical conditions or take certain medications. So it’s important not to take more Viagra than your doctor prescribes for you.

If your current dosage isn’t working well for your ED, talk with your doctor about increasing your dosage.

Is Viagra used long term?

Yes, Viagra is typically used as needed for ED. If you and your doctor determine that Viagra is safe and effective for you, you’ll likely use it as long as you have ED.

Dosage adjustments

A lower dosage of Viagra is safer for some people. This is typically due to certain factors, such as having specific medical conditions. These factors include:

• being 65 years or older
• having kidney or liver problems
• taking a certain type of drug called an alpha-blocker that treats high blood pressure or prostate disease, such as tamsulosin (Flomax), doxazosin (Cardura), or prazosin (Minipress)
• taking ritonavir (Norvir), an HIV medication

If any of the above factors apply to you, talk with your doctor. They may adjust your dosage of Viagra.

Get answers to some frequently asked questions about Viagra.

Is Viagra’s dosage based on weight?

No, the dosage of Viagra isn’t based on a person’s weight. Instead, Viagra’s dosage is based on your age, how well your kidneys and liver are working, and how well the drug works for your erectile dysfunction.

Does age affect Viagra dosage? If so, what would the dosage be for a 70-year-old vs. a 30-year-old?

Yes, your age is a factor in what dosage of Viagra is right for you.

As people get older, their heart, liver, and kidneys don’t work as well as they once did. This can cause an older adult’s body to break down drugs slower than a younger adult’s body. As a result, drugs stay longer in the body, which can raise the risk of side effects.

If you’re 65 years or older, your doctor may start you on a lower dosage of Viagra. The typical starting dosage of Viagra for a 70-year-old would be 25 milligrams (mg). For a 30-year-old who has no other medical conditions, the typical starting dosage would be 50 mg.

Regardless of your age, you’ll take your prescribed dose about an hour before sex.

If the prescribed dosage of Viagra works well for you and doesn’t cause bothersome side effects, you’ll likely continue taking it. If a dosage works well but causes bothersome side effects, your doctor may suggest a lower dosage. If a dosage doesn’t work to help you get or maintain an erection, your doctor may increase your dosage.

What would happen if I took a larger dose of Viagra than my doctor prescribed — for example, 150 mg or 200 mg?

You shouldn’t take more Viagra than your doctor prescribes. The maximum recommended dosage of Viagra is 100 mg per day. Taking higher doses of Viagra can increase your chances of having severe side effects, such as:

• dangerously low blood pressure, which may increase your risk for heart attack or stroke
• dizziness
• vision loss
• priapism, a painful erection that lasts longer than 4 hours and could lead to permanent damage to your penis if untreated