Viagra (sildenafil) is a prescription brand-name medication. The Food and Drug Administration (FDA) has approved it to treat erectile dysfunction (ED) in adults.

Viagra is an oral tablet that contains the active drug sildenafil. Sildenafil is also available in generic form. Viagra is classified as a phosphodiesterase type 5 (PDE5) inhibitor.

For information on the dosage of Viagra, including its pill form, strengths, and how to take the drug, keep reading. For a comprehensive look at Viagra, see this article.

This article describes typical dosages for Viagra provided by the drug’s manufacturer. When taking Viagra, always follow the dosage prescribed by your doctor.

Below are details about Viagra dosages commonly used to treat erectile dysfunction (ED).

Viagra form

Viagra comes as tablets that you swallow.

Viagra strengths

Viagra tablets are available in three strengths:

  • 25 milligrams (mg)
  • 50 mg
  • 100 mg

Typical dosages

The following information describes commonly recommended dosages for ED. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

You’ll likely start with a Viagra dose of 50 mg. You should ideally take Viagra about an hour before sex. You can take the drug 30 minutes to 4 hours before you anticipate sexual activity.

Based on how well you respond to this dosage and any side effects you have, your doctor may either increase your dose up to the maximum of 100 mg or decrease your dose to 25 mg.

You should not take Viagra more than once daily. And you should only take it as needed.

Long-term use

Viagra is meant to be used as a long-term treatment. If you and your doctor determine that Viagra is safe and effective for you, you’ll likely take it long term.

Below are answers to some frequently asked questions about Viagra dosages.

Is Viagra dosage based on age or weight?

Viagra dosage is not based on weight, but your age can affect your dosage.

Specifically, you may have a lower starting dosage than usual if you’re over age 65. For example, a 30-year-old might start at a dose of 50 milligrams (mg), while a 70-year-old might have a starting dose of 25 mg. This is because in older people, the body clears Viagra from your system more slowly.

If you have questions about Viagra dosages based on your age, talk with your doctor or pharmacist.

Is Viagra prescribed in dosages of 100 mg, 150 mg, or 200 mg?

The highest recommended Viagra dose for treating erectile dysfunction (ED) is 100 mg per day, according to the drug’s manufacturer. Doses of 150 mg or 200 mg would be considered off-label use. “Off-label” is when a drug is prescribed to treat a condition it isn’t approved to treat, or in a dose that’s not approved by the Food and Drug Administration (FDA).

If you have questions about the highest dosage of Viagra that’s safe for you, talk with your doctor or pharmacist.

What’s the dosage of Cialis vs. Viagra?

Both Cialis (tadalafil) and Viagra are prescribed to treat ED. Neither drug should be taken more than once per day.

Viagra is used as needed, meaning you only take a dose prior to sexual activity. Cialis can be prescribed for use as needed, but can also be prescribed for use once per day, every day (without timing the dose around sexual activity). This is the biggest difference in approved dosages of Cialis compared with Viagra.

If you have other questions about how Viagra and Cialis compare, check out this article. You can also talk with your doctor or pharmacist.

The Viagra dosage your doctor prescribes will depend on several factors. These include:

  • your age
  • other medications you may take
  • how you respond to Viagra, including any side effects you may have

Other medical conditions you have can also affect your Viagra dosage.

Dosage adjustments

Your doctor may start you on a lower Viagra dosage than usual if you:

Your doctor can give you more information on the safest Viagra dosage for you, including information about factors that can affect your dosage.

Viagra comes as tablets that you swallow. Usually, you’ll take your dose about an hour before sexual activity. But Viagra may be taken between 30 minutes and 4 hours before you anticipate sexual activity.

Viagra tablets may be taken with or without food. Keep in mind that meals high in fat (such as a cheeseburger) may cause Viagra to take longer than usual to start working.

Do not take more than one dose of Viagra per day. Doing this can increase your risk for serious side effects.

Viagra isn’t a medication you take every day. You’ll only take a dose as needed before sex, no more than once per day.

It’s important that you don’t use more Viagra than your doctor prescribes. For some medications, taking more than the recommended amount may lead to side effects or overdose.

If you take more than the recommended amount of Viagra

Call your doctor right away if you believe you’ve taken too much Viagra. Another option is to call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

The dosages in this article are typical dosages provided by the drug manufacturer. If your doctor recommends Viagra for you, they will prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes for you.

As with any drug, never change your dosage of Viagra without your doctor’s recommendation. If you have questions about the dosage of Viagra that’s right for you, talk with your doctor.

Besides learning about dosage, you may want other information about Viagra. These additional articles might be helpful:

  • More about Viagra. For information about other aspects of Viagra, refer to this article.
  • Side effects. To learn about side effects of Viagra, see this article. You can also look at Viagra’s patient information.
  • Drug comparison. To find out how Viagra compares with other erectile dysfunction (ED) drugs, such as Cialis, Levitra, and Stendra, read this article.
  • Details on your condition. For details about ED, see this list of related articles, as well as our men’s health hub.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.