Viagra

Sildenafil (sil DEN a fil) oral tablet is prescribed for erectile dysfunction (also called impotence). It’s a generic version of the brand-name drug Viagra. Sildenafil belongs to a group of drugs called phosphodiesterase 5 inhibitors.

Medically reviewed by Patricia Weiser, PharmD on April 20, 2023
Written by Sarah Lewis, PharmD

Introduction

This article describes sildenafil oral tablet’s uses and dosage, ways to save on cost, and more. Below you’ll find coupon options for sildenafil.

This article doesn’t describe or provide coupons for all forms and uses of sildenafil. To find out more about sildenafil for pulmonary arterial hypertension, see this article.

Side effects of sildenafil

Sildenafil may cause mild or serious side effects. More common mild side effects of sildenafil oral tablet and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age and overall health and any other medications you take.

To learn more about sildenafil oral tablet’s side effects, see this article or ask your doctor or pharmacist. You can also read the prescribing information for sildenafil oral tablet.

Mild side effects

More common mild side effects reported with sildenafil oral tablet are listed below.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Sildenafil oral tablet’s mild side effects include:

• back pain
• dizziness
• flushing (temporary warmth, redness, or deepening of skin color)
• headache
• indigestion (upset stomach)
• muscle aches
• nausea
• skin rash
• stuffy nose
• temporary vision problems
• mild allergic reaction*

* For details about this side effect, see the “Warnings for sildenafil” section below.

Serious side effects

Serious side effects of sildenafil oral tablet are listed below. With many drugs, serious side effects are possible but not common.

If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

Sildenafil oral tablet’s serious side effects include:

• heart rhythm problems and other heart-related side effects, including heart attack
• optic nerve damage 
• priapism (long lasting erection)
• sudden drop in blood pressure, which can lead to serious problems in people with heart disease
• sudden hearing loss
• severe allergic reaction*

* For details about this side effect, see the “Warnings for sildenafil” section below.

Common questions about sildenafil

Below you’ll find answers to a few commonly asked questions about sildenafil oral tablet.

How does sildenafil compare with other similar drugs, such as tadalafil?

Sildenafil oral tablet (Viagra) and tadalafil (Cialis) belong to a group of drugs called phosphodiesterase 5 (PDE5) inhibitors. Drugs that are PDE5 inhibitors have very similar side effects and warnings. But their dosages can be different.

Doctors can prescribe either sildenafil oral tablet or tadalafil to treat erectile dysfunction (ED). You take sildenafil oral tablet as needed for ED. With tadalafil, you take it every day or as needed for ED. This is because sildenafil oral tablet will work for up to 4 hours, while tadalafil’s effects can last up to 36 hours.

Both sildenafil oral tablet and tadalafil have other uses, in addition to treating ED. Talk with your doctor or pharmacist to find out more about how these drugs compare.

Is sildenafil used for sexual problems in females?

No, sildenafil oral tablet isn’t approved for sexual problems in females.* The drug is approved to treat erectile dysfunction (ED) in adult males.* (With ED, you have trouble getting or keeping an erection.)

Females can also have problems with sexual function or desire, and treatments are available. Talk with your doctor about treatment options if you’re having these problems.

* Sex and gender exist on spectrums. In this article, we use the term “female” and “male” to refer to a person’s sex assigned at birth.

How does sildenafil work? And how long does it take to start working?

Sildenafil oral tablet works by relaxing blood vessels that supply blood to the penis. This causes more blood to flow to the penis. Increased blood flow is what improves the ability to get and keep an erection.

Sildenafil oral tablet should start to work within about an hour of taking it. For some people, it starts to work within 30 minutes. The effect should last up to 4 hours in most cases. Do not take sildenafil tablet more than once per day.

To learn more about what you can expect with sildenafil oral tablet, talk with your doctor or pharmacist.

Does sildenafil cause long-term side effects?

Long-term side effects aren’t common with sildenafil oral tablet. Most of sildenafil’s side effects should go away as the dose wears off. In studies, specific side effects weren’t seen in people who took the drug for a long time.

However, in rare cases, certain serious side effects of sildenafil can continue after the drug is out of your system. Examples include priapism (long lasting erection) and optic nerve damage, which may lead to vision loss.

Talk with your doctor if you have questions about possible long-term side effects with sildenafil.

Is there a best time of day to take sildenafil? What should I do if I miss a dose?

No, there isn’t a recommended time of day to take sildenafil oral tablet. Your doctor will recommend you take it as needed for sexual activity. You should take it about an hour before sex. You may find that you can take it anywhere from 30 minutes to 4 hours before sex, depending on how your body responds.

Since you’ll use sildenafil oral tablet as needed, you’ll only take it when you’re ready to have sex. You can take a dose as soon as you remember if you’re going to have sex. Try to keep sildenafil oral tablet on hand so you have it when you need it for this use.

You should not take the drug more than once per day. Take sildenafil tablet exactly as your doctor prescribes.

Talk with your doctor or pharmacist if you have questions about when to take sildenafil.

Can sildenafil tablets be crushed, split, or chewed?

The drugmaker doesn’t give any advice about crushing, splitting, or chewing sildenafil oral tablet. To be sure, ask your pharmacist before crushing, splitting, or chewing sildenafil oral tablet.

Talk with your doctor or pharmacist if you have trouble swallowing tablets. If you feel like the drug isn’t working fast enough, you can ask your doctor whether there are other treatment options that might work faster.

Note: Crushing, splitting, or chewing sildenafil oral tablet won’t make its effects happen faster.

Dosage of sildenafil

The dosage of sildenafil oral tablet your doctor prescribes may vary based on your condition and certain other factors. Talk with your doctor about the dosage you should take.

Taking sildenafil

Sildenafil oral tablet is swallowed.

Your doctor will talk with you about how to take sildenafil oral tablet. They’ll explain how much to take and how often. Always follow your doctor’s recommendation.

Sildenafil oral tablet can be taken with or without food. However, if you take the drug right after a high fat meal, it can take longer to work. An example of a high fat meal is a cheeseburger and french fries.

See the “Common questions about sildenafil” section for information on missed doses and the best time to take this drug.

Overdose of sildenafil

You should not take more sildenafil than your doctor prescribes. For some drugs, doing so may lead to serious side effects or overdose.

If you think you’ve taken too much sildenafil, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Uses of sildenafil

The Food and Drug Administration (FDA) approves prescription drugs such as sildenafil for certain conditions. Approved uses for sildenafil oral tablet are described below.

Use for erectile dysfunction

Doctors may prescribe sildenafil oral tablet for treating erectile dysfunction (ED). (ED is also known as impotence.) It’s used for this purpose in adult males.* It’s usually prescribed as a long-term treatment.

With ED, you have trouble getting or keeping an erection. Taking sildenafil oral tablet can help improve the ability to get and keep an erection that’s firm enough for sexual intercourse.

* Sex and gender exist on spectrums. In this article, we use the term “male” to refer to a person’s sex assigned at birth.

Sildenafil coupon

You may be able to save money on your prescription for sildenafil oral tablet by using our Perks discount coupons. These can be found at the end of this article.

If you have questions about how to pay for sildenafil, talk with your doctor or pharmacist. You can also learn more about the cost of sildenafil in this article.

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

Interactions of sildenafil

For some medications, certain things may affect how the drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take sildenafil, ask your doctor to check for possible interactions. They can check for interactions these items may cause with sildenafil. Be sure to tell them about any of the following you take or use:

• prescription medications*
• over-the-counter medications
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for sildenafil” section below.

* Doctors will not prescribe sildenafil with nitrates, such as nitroglycerin (Nitrostat) or isosorbide (Monoket). They also won’t prescribe sildenafil with guanylate cyclase stimulators, such as riociguat (Adempas) or vericiguat (Verquvo). For more information, talk with your doctor or pharmacist.

Warnings for sildenafil

Sildenafil should not be taken by certain people. And some other people should cautiously take this drug. Precautions for taking this drug are described below.

Warnings

Sildenafil could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether sildenafil oral tablet is a safe option for you.

Tell your doctor about your overall health and any past health conditions before you take sildenafil oral tablet. Health conditions and other factors you and your doctor should discuss include:

• use of alpha-blocker drugs
• bleeding problems
• blood cell problems
• heart and blood vessel disease
• high blood pressure
• kidney or liver problems
• physical abnormalities of the penis, such as Peyronie’s disease
• pulmonary hypertension
• recent stroke or heart attack
• retinitis pigmentosa
• stomach ulcers

Allergic reaction

Sildenafil can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to sildenafil or any of its ingredients, your doctor will likely not prescribe sildenafil. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to sildenafil, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Pregnancy or breastfeeding and sildenafil

Information about sildenafil and pregnancy and breastfeeding is described below.

Sildenafil and pregnancy

It’s not known whether sildenafil is safe to take during pregnancy.

The drug hasn’t been studied in pregnant people. This is because sildenafil oral tablet (the generic version of Viagra) is used to treat erectile dysfunction (ED) in adult males.*

* Sex and gender exist on spectrums. In this article, we use the term “male” to refer to a person’s sex assigned at birth.

Sildenafil and breastfeeding

It’s not known whether sildenafil is safe to take while breastfeeding.

Sildenafil may pass into breast milk. But researchers haven’t studied how or if this affects a child who is breastfed. This is because sildenafil oral tablet (the generic version of Viagra) is used to treat ED in adult males.*

* Sex and gender exist on spectrums. In this article, we use the term “male” to refer to a person’s sex assigned at birth.

What to ask your doctor

This article describes sildenafil oral tablet’s uses and dosage, ways to save on cost, and more. Let your doctor know if you have questions about sildenafil or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Can sildenafil tablets expire?
• How does sildenafil oral tablet compare to other drugs that treat erectile dysfunction?
• What other options do I have if sildenafil oral tablet isn’t working?

Article resources

• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
• Sildenafil- sildenafil tablet, film coated. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/8a0dcf6a-b21a-4ddf-b365-29d1e5060240/spl-doc

Disclaimer: Optum Perks 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.