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Viagra, the brand name of the drug sildenafil, is now sold as a generic drug by many manufacturers around the world. Sildenafil is essentially the same medication as Viagra, which was the first major erectile dysfunction (ED) medication on the market and is made by Pfizer.

Generic Viagra hasn’t been around very long. Though Pfizer’s patent on the popular ED medication ran out in 2020, Pfizer started making and selling generic sildenafil in 2017. Once other companies could legally sell their own sildenafil tablets in 2020, the options for consumers quickly expanded.

The pharmaceutical giant Pfizer discovered the erectile dysfunction benefits of sildenafil by accident.

Researchers were testing the medication to treat high blood pressure and angina — chest pain associated with heart disease. They found that the medication was especially effective at inducing erections. The Food and Drug Administration (FDA) approved Viagra in 1998, making it the first oral drug specifically prescribed for erectile dysfunction.

Pfizer was also the first to introduce generic Viagra through a subsidiary called Greenstone. Other companies around the world also manufacture sildenafil pills, including:

  • Teva Pharmaceuticals
  • Aurobindo
  • Cambia
  • Mylan
  • Bristol Labs

Sildenafil is best known as a treatment for erectile dysfunction, the inability to get or keep an erection. Sildenafil is meant to be taken before having sex, with the understanding that its effects last only a few hours.

Sildenafil is also approved for the treatment of pulmonary hypertension (PH) — elevated blood pressure in the arteries of the lungs and in the right side of the heart. Revatio is the brand name of sildenafil prescribed for PH.

Generic sildenafil is always sold as sildenafil. There are currently no other brand names for the drug, aside from Viagra and Revatio.

In the United States, sildenafil for ED or PH requires a prescription. The United Kingdom allows for over-the-counter sales of the drug, in part to discourage the market for fake sildenafil. Sildenafil is one of the most commonly counterfeited drugs in the world.

Instead of “the little blue pill,” as Viagra is known, sildenafil is often sold as a little white pill by Pfizer’s competitors. The appearance of the pill doesn’t change its effectiveness or how it works in the body.

While generic sildenafil and Viagra are equally safe and effective, the medications have one key difference: cost. Viagra costs around $60 to $70 per tablet. Generic sildenafil can range from under $1 to up to $10 per pill, depending on the manufacturer and dose.

Sildenafil doesn’t cure ED. It treats ED symptoms. Likewise, sildenafil doesn’t cure PH. It just helps control blood pressure in the arteries in the lungs.

Sildenafil is in a class of medications called phosphodiesterase type 5 (PDE5) inhibitors. These drugs restrict the action of phosphodiesterase enzymes, which break down cyclic guanosine monophosphate. This is a type of molecule that relaxes smooth muscle tissue in the body, such as those in the blood vessels that allow the penis to become erect. Taking sildenafil improves circulation by helping the arteries relax enough to fill more easily with blood.

Sildenafil is quickly absorbed into the bloodstream, reaching maximum concentration in about 1 hour for most users. Generic Viagra, like other PDE5 inhibitors, can cause a drop in blood pressure. If you take medications for blood pressure control or tend to have low blood pressure, ask your doctor if it’s safe to use sildenafil.

Sildenafil doesn’t trigger an erection on its own, nor does it increase sexual desire. Sexual stimulation is still required. However, for most healthy people, sildenafil can make an erection easier to get.

A 4-year study published in 2007 found that sildenafil is generally safe to use over the long term. Other data pulled from clinical trials in 2016 noted that sildenafil is effective without severe side effects regardless of age.

Generic Viagra (sildenafil) is available as a 25-milligram (mg), 50-mg, and 100-mg tablet. The 50-mg dose is standard, though your doctor may start you on a 25-mg dose to see if that is sufficient.

Generic Revatio (sildenafil) is available as a 20-mg tablet.

For ED, take sildenafil on an as-needed basis, ideally 1 hour before intercourse. However, it may be effective as soon as 30 minutes before intercourse and may still be effective 3 or 4 hours later.

After 4 hours, the effects of sildenafil tend to wear off. It’s recommended that you take sildenafil no more than once daily.

Sildenafil prescribed for PH is available as a 5-mg and 20-mg pill and in liquid form. It’s usually taken 3 times per day.

Sildenafil may cause side effects, most of which are minor and temporary. Some of the most common are:

  • headaches
  • flushing, or a feeling of warmth under the skin
  • heartburn
  • diarrhea
  • insomnia
  • tingling in the limbs
  • muscle aches
  • sensitivity to light

Serious side effects of sildenafil

More serious side effects should prompt an immediate call to your doctor or 911. They include:

  • blurry vision or sudden and severe loss of vision
  • diminished hearing
  • ringing in ears
  • dizziness or lightheadedness
  • fainting
  • shortness of breath
  • chest pain
  • itching or burning during urination
  • rash
  • erection that is painful or lasts longer than 4 hours (priapism)

Like any medication, sildenafil can have some potentially serious interactions with other drugs.

Combining with certain blood pressure and heart medications can cause changes in blood pressure

In particular, don’t take sildenafil if you take a nitrate medication for angina or high blood pressure.

If you take other medications for high blood pressure, you may be at risk of experiencing a dangerous drop in blood pressure. These include:

A drop in blood pressure can result in:

  • dizziness
  • headache
  • fainting or falling

Severe blood pressure drops can also result in less oxygen moving through your organs.

Don’t take with other ED medications

Avoid taking sildenafil with any other ED medications. The combination can lower blood pressure, causing fainting, dizziness, and in some rare cases, heart attack.

Combining with alcohol can affect blood pressure

Alcohol and sildenafil can combine to lower blood pressure too much. Avoid alcohol if you’re taking sildenafil.

Grapefruit can delay sildenafil’s effect and increase the chance of side effects

The only real food interaction that can occur with generic Viagra is with grapefruit and grapefruit juice. These products can raise the levels of sildenafil in your body, but can also delay the time the drug takes effect.

CP450 drugs increase the chance of side effects and change the effectiveness of sildenafil

Similar to grapefruit, medications known as cytochrome P450 (CP450) inhibitors and substrates can delay how long it takes sildenafil to work and can increase your chance of side effects. CP450 inducers, such as modafinil, reduce the effects of sildenafil if taken at the same time.

CP450 medications include:

  • cimetidine
  • clopidogrel
  • chloramphenicol
  • fluvoxamine
  • omeprazole
  • modafinil

While some of what’s sold as generic Viagra online is fake, several reputable companies do sell sildenafil online. Each of the companies below has been vetted by our team for medical and business standards. Learn more here.

Roman

Roman is a telehealth company that focuses on treatment for ED, including generic Viagra. With Roman, you can make online and in-person doctor’s visits and get your prescription filled and refilled.

Roman offers the following ED treatments:

  • generic Viagara (sildenafil)
  • brand name Viagra
  • generic Cialis (tadalafil)

The cost for generic Viagra from Roman starts at $34 for a single oral tablet.

Hims

To purchase medication from telehealth company Hims, you’ll need to fill out a health questionnaire, which is then reviewed by an on-staff doctor.

The company offers the following ED treatments:

  • generic Viagra (sildenafil)
  • brand name Viagra
  • brand name Cialis
  • generic Cialis (tadalafil)
  • Stendra (avanafil)

The cost for generic Viagra from Hims starts at $24 per month.

Lemonaid

Lemonaid is a telehealth company that offers a wide range of services. You can see a doctor online without having to book time off to go to an in-person appointment.

The company has a mail-order pharmacy that allows you to get meds delivered straight to your door. The downside, though, is that they don’t take insurance — even for non-ED drugs.

Doctors can prescribe the following ED treatments:

  • generic Viagra (sildenafil)
  • brand name Viagra
  • Stendra (avanafil)
  • brand name Cialis
  • generic Cialis (tadalafil)
  • Levitra (vardenafil)

ED pill costs start at $2 per pill and shipping is free.

There are a number of different treatments for ED. In addition to medications or other medical interventions, maintaining a healthy lifestyle can affect the success of your ED treatment.

Sildenafil is just one of several ED medications on the market.

Other oral medications

The four major PDE5 inhibitors are:

  • sildenafil (Viagra)
  • tadalafil (Cialis)
  • vardenafil (Levitra)
  • avanafil (Stendra)

All of those medications, except avanafil (Stendra), are available as generic medications.

Penis pump

There are some nonpharmacological treatments for ED, including a vacuum erection device, also known as an erectile dysfunction pump.

It works by placing a seal around the end of the penis and attracting blood to the arteries in the penis by air suction.

Surgery and injections

Penile implants and penile injections to treat ED are other options to consider. Talk with a urologist to learn more about treatments you may want to try.

What is generic Viagra?

Generic Viagra, or sildenafil, is the non-brand name version of the popular ED drug. It’s virtually identical to the brand name drug, except it may be a different color (instead of blue, like Viagra) and costs a lot less.

How much does generic Viagra cost?

Generic Viagra usually costs anywhere from under $1 to $10 for each tablet.

Generic Viagra, or sildenafil citrate, works the same as Viagra, but at a lower cost.

While Pfizer still manufactures the “little blue pill,” other companies, globally and in the United States, make sildenafil. It may look different, but it’s still an effective treatment for erectile dysfunction.