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Sildenafil treats erectile dysfunction (ED). It is the active ingredient in Viagra. We cover sildenafil uses, dosage, and more in this article. We also feature the best places to buy sildenafil.
This article takes a closer look at sildenafil, ED, and how the drug works to relieve the condition.
- Best low cost option: Roman | Skip to review
- Best range of ED medication: Hims | Skip to review
- Best for insurance, FSA, and HSA coverage: Optum Store | Skip to review
Sildenafil is a popular treatment for ED. People with ED have difficulty getting or maintaining an erection. It is a widespread condition, but many people find it difficult to discuss.
The main ingredient in sildenafil is sildenafil citrate. The inactive ingredients include:
- microcrystalline cellulose
- anhydrous dibasic calcium phosphate
- croscarmellose sodium
- magnesium stearate
- hypromellose
- titanium dioxide
- lactose
- triacetin
- artificial colors
Viagra is just one brand name option containing sildenafil. Other products might use different inactive ingredients.
Another brand name medication containing sildenafil is Revatio. In addition to treating ED, Revatio treats pulmonary hypertension.
A person cannot get sildenafil without a valid prescription from a doctor in the United States.
Sildenafil comes in tablet form. Tablets are available in strengths of 25, 50, and 100 milligrams (mg). It also comes in 20 mg doses as the generic form of Revatio, which is not FDA-approved for ED.
People generally take a 50-mg sildenafil tablet approximately 1 hour before sex. Regardless of the dose, a person should take sildenafil exactly as a doctor recommends and not more than once per day.
Sildenafil is fast acting, and its effects typically last about 1 hour. However, sildenafil does not instantaneously produce an erection, and sexual arousal is necessary for the drug to work. Sildenafil also does not affect a person’s sex drive, or libido.
Sildenafil belongs to a class of medications called phosphodiesterase type 5 (PDE5) inhibitors. These inhibit phosphodiesterase enzymes, which degrade the molecules that relax the muscle tissue. This allows for increased blood flow, causing an erection.
Sildenafil does not cure ED. However, it can help treat the symptoms of the condition.
People are
A person with symptoms of ED can try taking sildenafil if they first discuss it with a healthcare professional to ensure it is the right treatment for them. If appropriate, a doctor will provide a prescription.
The National Health Service (NHS) in the United Kingdom states that most males over the age of 18 can take sildenafil for ED.
People with
ED may sometimes be a sign of an underlying condition, so sildenafil may help treat some symptoms in individuals with certain health conditions.
Some people with the following conditions may take sildenafil for treating ED:
- type 2 diabetes
- multiple sclerosis
- heart disease
- high blood pressure
- atherosclerosis, which refers to the hardening of the arteries
Learn more about the causes of ED.
Some common side effects of sildenafil include:
- headaches
- flushing
- indigestion (dyspepsia)
- vision changes
- nausea
- dizziness
- rashes
- nasal congestion
- back pain
More serious side effects can include sudden loss of vision or hearing, and prolonged, painful erections, known as priapism. Anyone using sildenafil who experiences these side effects should seek immediate medical attention.
Dietary interactions
A person should avoid consuming large amounts of grapefruit with sildenafil. Consuming grapefruits or grapefruit juice can increase the levels of sildenafil in the body, potentially leading to toxicity.
Combining sildenafil with alcohol can also cause interactions. A
- indigestion
- skin rash
- headache
- facial flushing
- chest discomfort and palpitations
- dizziness
- altered vision
- nasal congestion
Other warnings
If a person takes nitrate medication that lowers their blood pressure, they cannot take sildenafil. This is because sildenafil can further lower blood pressure and cause serious side effects, such as life threatening
Nitrate medication includes nitroglycerin, isosorbide mononitrate, and isosorbide dinitrate.
Sildenafil is also unsuitable for people with heart conditions due to its effect on arteries. The drug stimulates the release of
It is important to note that sildenafil is not a form of birth control, so it does not prevent pregnancy. It also does not protect against sexually transmitted infections.
What to do
If a person has taken too much sildenafil and has trouble breathing, is unconscious or has a seizure, they or someone near them should call emergency services at 911 immediately.
Otherwise, a person can call America’s Poison Centers for emergency attention at 1-800-222-1222 or visit the Poison Help website.
A sign of a sildenafil overdose is an increase in the severity and duration of common side effects. Another sign of a sildenafil overdose is visual changes,
There
Medical News Today’s methodology
Medical News Today chooses sildenafil retailers based on the following criteria:
- Company reputation: MNT brands that have undergone internal vetting of medical and business standards. The brands we choose are reputable and reliable, with transparent business practices and positive reviews on the Better Business Bureau and Trustpilot.
- Product transparency: MNT selects retailers that clearly state its ingredients, side effects, and the recommended sildenafil dosage.
- Safety: MNT selects brands that require a doctor’s prescription before customers can order sildenafil. This ensures that a person can safely take sildenafil and that the professional is dispensing it responsibly. Counterfeit ED medication is
common , so MNT only features brands that provide genuine sildenafil. - Price: MNT selects products that suit a range of budgets, including choosing brands that offer both brand-name and generic sildenafil.
Medical News Today follows a strict product selection and vetting process. Learn more here.
The table below compares the telehealth companies in this article on their sildenafil and Viagra offering.
| Price | Accepts insurance | Forms offered | Consultation cost | |
|---|---|---|---|---|
| Roman | $4–$10 | no | • sildenafil • Viagra | $0 |
| Hims | $4–$10 | no | • sildenafil • Viagra | $0 |
| Optum Store | from $6 | no | • sildenafil • Viagra | $0 |
People can use telehealth companies to buy sildenafil online. They will often need to answer health questions and have an online appointment with a doctor before they can get a prescription for sildenafil. Below, we look at the best places to buy sildenafil online.
Please note that the writer of this article has not tried any of these products. All information presented here is purely research-based.
If a person cannot take sildenafil, wishes to avoid it, or wants to try something else, there are other options to treat ED.
Alternative PDE5 inhibitors include:
- Avanafil (Stendra): This option increases blood flow to the penis. A 2022 study that included 220 participants and lasted 12 weeks found that avanafil is
slightly more effective than sildenafil and may work more quickly. - Tadalafil (Cialis): This drug helps people get erections by increasing blood flow to the penis. The United Kingdom’s National Health Service states that tadalafil can be effective at helping people achieve erections for up to 36 hours.
- Vardenafil (Levitra): This works by increasing blood flow to the penis. It dissolves in the mouth, so a person does not need to take it with water. A meta-review of 14 studies found that vardenafil significantly improved erectile function when compared to a placebo.
Other treatment options include:
- ED pumps: This type of device helps a person get an erection by creating a vacuum around and drawing blood into the penis. A person can then maintain the erection for up to 30 minutes by slipping an elastic ring around the base of their penis. Roughly 75% of males can get an erection with this approach. Learn about the best penis pumps.
- Penile implants: This approach is generally a recommendation for older individuals who did not get good results from treating ED with medication. It involves a surgical procedure to insert a prosthetic device into the penis. The device, which can be either bendable or inflatable, stiffens the penis enough for sex. Most people who have this procedure report good results.
- Penile injections: This technique involves a person injecting Alprostadil, sometimes mixed with other medication, into the side of their penis. It can reportedly help 85% of people get erections that last 20–30 minutes, even after orgasm. Individuals can inject themselves on their own, but they should first learn how to do it in a doctor’s office.
- Prescription testosterone: Testosterone therapy treatment can improve ED either by itself or in combination with medications such as Viagra. However, a person must have both a low sex drive and low blood levels of testosterone for this treatment to be effective. According to the Urology Care Foundation, such cases are rare.
People may also wish to consider making lifestyle adjustments to help manage the symptoms of ED.
ED treatment guidelines from the American Urological Association recommend counseling for people with ED and related health issues, such as cardiovascular problems and obesity. This counseling should cover lifestyle changes a person can make to improve their overall health and potentially their erectile function. These may include:
- quitting smoking, if they smoke
- limiting alcohol intake, if they drink
- increasing physical activity
Mental health symptoms may also contribute to ED. Anxiety and stress about sex, for example, can make it more difficult for a person to get or maintain an erection. Talking with a mental health professional may help.
Below, we answer the most common questions about sildenafil.
If a person takes too much sildenafil, it can cause a range of side effects, including blurred vision, hearing loss, low blood pressure, and a prolonged and painful erection.
In the event of breathing difficulties, unconsciousness, and seizures, people should call 911 immediately.
Otherwise, people who have taken too much sildenafil can call America’s Poison Centers for emergency help at 1-800-222-1222 or visit the Poison Help website.
Sildenafil can help a person get and maintain an erection with sexual stimulation.
Sildenafil should typically begin working within 30–60 minutes after a person takes it. It can continue working for up to 4 hours.
Sildenafil is the active ingredient in Viagra. Both sildenafil and Viagra come in doses of 25, 50, and 100 mg. As such, they will be equally as strong.
Sildenafil is usually effective for around 4 hours. However, this does not mean a person will have an erection for this long. The erection should only occur when a person is aroused. If a person experiences an erection that lasts a long time or is painful, they should seek emergency medical attention.
People should follow the advice of doctors and the prescribing information included with their medication. A person should not take sildenafil more than once every 24 hours.
Sildenafil is the generic version of the brand name drug Viagra. Sildenafil is an effective ED drug available at a fraction of the cost of Viagra.
Sildenafil is just as safe and effective as Viagra. However, as with Viagra, it carries the risk of potential side effects and drug interactions.
People who experience ED should discuss their treatment options with a doctor.