Got a question about Viagra? We’ve got answers. From the history of the drug to information about Viagra’s onset of action, potential side effects and more, we’ve answered 22 of the most common questions about Viagra (as well as its generic counterpart, sildenafil) below.
When Was Viagra Invented?
Sildenafil, the active ingredient in Viagra, was originally developed in the 1980s as a treatment for angina. During testing, Pfizer discovered that the medication was more effective at treating erectile dysfunction than angina and decided to market it for this purpose.
After undergoing clinical testing throughout the 1990s, Viagra was patented in 1996 and went onto the market in 1998 after receiving FDA approval. This means that it’s been in use for over 20 years, making it the oldest FDA-approved erectile dysfunction treatment on the market.
How Does Viagra Work?
Viagra belongs to a class of drugs called PDE5 inhibitors. These medications work by blocking the degradative action of the PDE5 enzyme (cGMP-specific phosphodiesterase type 5), which plays an important role in regulating blood flow to the sponge-like erectile tissue of the penis.
In simple terms, Viagra (as well as other erectile dysfunction drugs, such as Cialis and Levitra) works by improving blood flow into the soft tissue of your penis. This makes it easier to get and maintain an erection. Our guide to how Viagra works covers this process in more detail.
Does Viagra Always Work?
Viagra works by increasing blood flow into the soft tissue of your penis. It’s very effective at this, making it a great treatment option if you have erectile dysfunction caused by a health issue that affects blood flow to your penis.
However, Viagra does not directly affect the psychological side of sexual performance, such as your level of interest in sex, arousal level or sexual confidence. This means that it’s still possible to experience erectile dysfunction as a result of a psychological issue, even with Viagra.
ED can occur for a large variety of reasons, from performance anxiety to depression. Our guide to what you can do if Viagra doesn’t work covers this in greater detail and explains how you can overcome common causes of ED to improve your sexual performance.
What Other Health Conditions is Viagra Used For?
Viagra is only marketed as a treatment for erectile dysfunction. However, sildenafil, the active ingredient in Viagra, is also used to treat conditions such as pulmonary arterial hypertension, which is a form of high blood pressure that affects the lungs.
Revatio, which contains a lower dose of sildenafil than most Viagra tablets, is used exclusively as a treatment for pulmonary arterial hypertension.
When Should You Consider Using Viagra?
Viagra can be a safe, effective treatment for men of any age. You should consider using Viagra if you experience erectile dysfunction that affects your sex life, whether it’s an occasional issue or something that occurs frequently.
Our list of erectile dysfunction risk factors covers the main factors that can contribute to ED and make Viagra worth considering. Because Viagra is a prescription medication, your doctor will be able to tell you more about whether it’s an appropriate treatment option for you.
How Long Does it Take for Viagra to Work?
Sildenafil, the active ingredient in Viagra, usually starts working about 30 minutes after you take it. If you’ve recently eaten a large meal, particularly a meal that’s high in fat, it might take up to one hour before you notice the effects of Viagra.
For best results, you should take Viagra on a relatively empty stomach about one hour before you expect to have sex.
Is it Possible to Make Viagra Work Faster?
Your body needs time to absorb the sildenafil in a Viagra tablet after you swallow it. While there isn’t anything you can directly do to speed up your body’s absorption of sildenafil, you can make Viagra work faster by taking it in the right conditions.
For the fastest effects, take Viagra on an empty stomach and avoid eating any food for an hour after you take the medication. This means that your body will be able to absorb the sildenafil as soon as it reaches your stomach, without first having to digest other food or liquids.
What is a Normal Dose of Viagra?
Viagra, whether from Pfizer or in generic form as sildenafil, is available in several different doses. The smallest dose of Viagra is 25mg (generic sildenafil is also available in a smaller 20mg dose), while the maximum dose of Viagra contains 100mg of sildenafil.
Depending on your needs and the severity of your ED symptoms, you might be prescribed a 25mg, 50mg or 100mg dose of Viagra by your doctor. Studies show that a 50mg dose usually provides significant improvements for men with mild-to-moderate erectile dysfunction.
Our guide to Viagra dosages goes into more detail on the different dosages of Viagra used to treat erectile dysfunction and their effectiveness.
What’s the Difference Between Viagra and Sildenafil?
Viagra and sildenafil are the same thing. Viagra is the brand name for the original medication developed and marketed by Pfizer, whereas sildenafil is the active ingredient in the tablet that treats ED. One tablet of Viagra contains either 25mg, 50mg or 100mg of sildenafil.
Generic sildenafil has all of the same effects and side effects of Viagra. You’ll notice the same improvement in your erection quality and sexual performance, as well as the exact same onset of action, potential side effects and overall effectiveness.
What Are The Side Effects of Viagra?
Viagra is a safe and effective medication that typically only causes minor side effects. The most common side effects of Viagra are headaches, nasal congestion, facial flushing, indigestion and muscle aches.
These side effects also often occur with other ED medications, such as Cialis and Levitra. Our guide to what you should expect from erectile dysfunction medication goes into more detail on the potential side effects of Viagra.
How Long Does Viagra Stay in Your System?
The effects of Viagra typically last for three to four hours, after which the medication stops being effective at preventing erectile dysfunction. If you take Viagra on a fairly empty stomach and do not eat a large meal after using it, it will typically take five to six hours for it to exit your system.
Small amounts of Viagra could remain in your system for up to 20 hours. Certain side effects of Viagra, such as nasal congestion, facial flushing and heartburn, can continue for several hours after the medication exits your system.
How Often Can You Take Viagra?
Viagra is designed for use as needed, meaning you should take it about one hour before you plan to have sex. Regardless of the exact dosage of Viagra you’re prescribed, you should not take this medication more than one time per day.
If you want to have sex multiple times in one day and need a longer-lasting erectile dysfunction treatment, do not take more than one Viagra dose. Instead, it’s best to talk to your doctor about switching to a longer-lasting medication, such as Cialis (tadalafil).
What Other Medications Work Like Viagra?
Viagra is one of several erectile dysfunction medications currently on the market. Similar drugs include Cialis (tadalafil), which provides similar effects to Viagra but lasts for significantly longer in the body, and Levitra (vardenafil), which has similar effects to Viagra.
Our guide to the most common erectile dysfunction treatments and drugs lists the most widely used medications in this category and their effects.
Are Natural Alternatives to Viagra Available?
There are countless supplements on the market that claim to provide similar results to Viagra, Cialis and other FDA-approved erectile dysfunction medications.
Although many over-the-counter supplements promise similar results to Viagra, few are reliable options for preventing ED. These supplements tend to contain ingredients such as “horny goat weed” (actually epimedium) that claim to boost testosterone and improve erections.
There is no significant scientific evidence proving that these ingredients work as treatments for erectile dysfunction. Many of these “natural” male enhancement supplements actually contain secret, unlisted ingredients such as powdered sildenafil and tadalafil.
The FDA maintains a list of tainted male enhancement supplements here. These supplements do not produce similar effects to Viagra, Cialis or Levitra and should not be viewed as reliable treatments for erectile dysfunction.
Other supplements, such as certain vitamins and niacin, may help to improve erection quality and reduce the severity of erectile dysfunction. However, these are significantly less effective than FDA-approved treatments like Viagra and are rarely suitable for severe cases of ED.
Is it Possible to Treat ED Without Viagra?
In some cases, it’s possible to treat erectile dysfunction and improve your sexual performance without using medication like Viagra.
Erectile dysfunction can occur for a variety of reasons. If your ED is caused by an underlying health condition or habit such as obesity, tobacco use, low testosterone or a dietary issue, it might be possible to reduce the severity of your symptoms without the use of Viagra.
This might involve using a hormonal treatment, changing your use of other medications, losing weight or making changes to your lifestyle to improve your general health and reduce your risk of being continually affected by ED.
When Will Generic Viagra be Available?
Generic sildenafil (the active ingredient in Viagra) is already available in the United States, as well as in numerous other countries. Using our online service, you can order generic sildenafil online, subject to doctor’s approval and following an online consultation with a physician.
Other erectile dysfunction drugs, such as tadalafil (a generic form of Cialis) are also available online.
Is Viagra Available Over the Counter?
In the United States, Viagra is a prescription medication, meaning you’ll only be able to buy it with a prescription from your doctor. Subject to doctor approval, you can buy sildenafil online after completing an online consultation with a physician.
What Happens if a Woman Takes Viagra?
Since Viagra works by increasing blood flow to the soft erectile tissue of the penis, it’s not an effective medication for women. Studies of Viagra in women show that while it does produce some minor benefits, it can also cause side effects such as nausea, flushing and headache.
Women with sexual performance or desire issues should not use Viagra. Instead, it’s best to speak with your doctor about treatment options. From hormonal medication to newer sexual drugs such as Addyi (flibanserin), there are now several similar medications for women.
Does Viagra Expire?
Like most medications, Viagra can become less effective over time and expire if it’s left unused for too long. Take note of the expiration date printed on your Viagra or generic sildenafil and aim to use the medication as prescribed before it expires.
If your Viagra has expired, do not use it. Instead, throw away the old medication and purchase a new packet of Viagra or generic sildenafil.
Is it Safe to Use Viagra and Other ED Medications Together?
It is not recommended to take Viagra and other ED medications such as Cialis or Levitra at the same time. Doing so can significantly increase each medication’s effects, creating a higher risk that you will experience side effects such as headache, nausea and cardiovascular issues.
If you find that Viagra is not fully effective at treating your erectile dysfunction, do not combine it with other medication. Instead, talk to your doctor about increasing your dose of Viagra or using a longer-lasting erectile dysfunction medication such as Cialis.
What if Viagra Doesn’t Work?
Viagra is highly effective at treating erectile dysfunction, with most men experiencing no issues achieving an erection after taking a 50mg or 100mg dose. However, it’s still possible for Viagra to fail in some situations.
While Viagra works well as a treatment for the physical side of erectile dysfunction, it does not treat a low sex drive or lack of arousal. Our guide to what you should do if Viagra doesn’t work — linked above — covers this topic in more detail and lists other options for improving your sexual performance.
What Drugs Should Be Avoided While Using Viagra?
Viagra can interact with several widely-used medications, including nitrates commonly used to treat high blood pressure and CYP3A4 inhibitors used to treat fungal infections.
When used with nitrates, Viagra can cause a severe, sudden drop in blood pressure that can lead to significant health risks. Do not use Viagra if you use nitrates. If you’re prescribed any nitrates to treat hypertension, you must inform your doctor of this before discussing Viagra.
While CYP3A4 inhibitors such as ketoconazole do not cause a drop in blood pressure when used with Viagra, they can prevent the body from properly metabolizing sildenafil and lead to higher-than-normal concentrations of Viagra in the body.
Finally, grapefruit juice can have similar effects, causing the level of sildenafil in your blood to increase beyond its normal level. Drugs.com maintains a full list of medications and foods that have the potential to interact with sildenafil.
Important Safety Information
IMPORTANT SAFETY INFORMATION
Do not take Sildenafil (sildenafil citrate) if you:
- take any medicines called nitrates, often prescribed for chest pain, or guanylate cyclase stimulators like Adempas (riociguat) for pulmonary hypertension. Your blood pressure could drop to an unsafe level
are allergic to sildenafil, as contained in Sildenafil and REVATIO, or any of the ingredients in Sildenafil
Discuss your health with your doctor to ensure that you are healthy enough for sex. If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help
Sildenafil can cause serious side effects. Rarely reported side effects include:
- an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis
- sudden vision loss in one or both eyes. Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy (NAION). Stop taking Sildenafil and call your healthcare provider right away if you have any sudden vision loss
sudden hearing decrease or hearing loss. Some people may also have ringing in their ears (tinnitus) or dizziness. If you have these symptoms, stop taking Sildenafil and contact a doctor right away
Before you take Sildenafil, tell your healthcare provider if you:
- have or have had heart problems such as a heart attack, irregular heartbeat, angina, chest pain, narrowing of the aortic valve, or heart failure
- have had heart surgery within the last 6 months
- have pulmonary hypertension
- have had a stroke
- have low blood pressure, or high blood pressure that is not controlled
- have a deformed penis shape
- have had an erection that lasted for more than 4 hours
- have problems with your blood cells such as sickle cell anemia, multiple myeloma, or leukemia
- have retinitis pigmentosa, a rare genetic (runs in families) eye disease
- have ever had severe vision loss, including an eye problem called NAION
- have bleeding problems
- have or have had stomach ulcers
- have liver problems
have kidney problems or are having kidney dialysis have any other medical conditions
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
Sildenafil may affect the way other medicines work, and other medicines may affect the way Sildenafil works, causing side effects. Especially tell your healthcare provider if you take any of the following:
- medicines called nitrates
- medicines called guanylate cyclase stimulators such as Adempas (riociguat)
- medicines called alpha-blockers such as Hytrin (terazosin HCl), Flomax (tamsulosin HCl), Cardura (doxazosin mesylate), Minipress (prazosin HCl), Uroxatral (alfuzosin HCl), Jalyn (dutasteride and tamsulosin HCl), or Rapaflo (silodosin). Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. In some patients, the use of Sildenafil with alpha-blockers can lead to a drop in blood pressure or to fainting
- medicines called HIV protease inhibitors, such as ritonavir (Norvir), indinavir sulfate (Crixivan), saquinavir (Fortovase or Invirase), or atazanavir sulfate (Reyataz)
- some types of oral antifungal medicines, such as ketoconazole (Nizoral) and itraconazole (Sporanox)
- some types of antibiotics, such as clarithromycin (Biaxin), telithromycin (Ketek), or erythromycin
- other medicines that treat high blood pressure
- other medicines or treatments for ED
Sildenafil contains sildenafil, which is the same medicine found in another drug called REVATIO. REVATIO is used to treat a rare disease called pulmonary arterial hypertension (PAH). Sildenafil should not be used with REVATIO or with other PAH treatments containing sildenafil or any other PDE5 inhibitors (such as Adcirca tadalafil)
Sildenafil does not protect against sexually transmitted diseases, including HIV.
The most common side effects of Sildenafil: headache; flushing; upset stomach; abnormal vision, such as changes in color vision (such as having a blue color tinge) and blurred vision; stuffy or runny nose; back pain; muscle pain; nausea; dizziness; rash.
Sildenafil (sildenafil citrate) is prescription medicine used to treat erectile dysfunction (ED).
Sildenafil is not for women or children.