Key takeaways:
Viagra (sildenafil) is an oral medication that treats erectile dysfunction (ED). It works by causing more blood flow to the penis. This helps you to achieve and maintain an erection.
You can take Viagra 30 minutes to 4 hours before sexual activity. But it shouldn’t be taken more than once daily. For most men, Viagra begins to work within an hour.
Taking Viagra with food can delay the time it takes to start working. For quicker onset, take Viagra on an empty stomach.
Viagra is available as a lower-cost generic. GoodRx can help you save over 98% off the average retail price of the generic version. With GoodRx Care Direct, you can also get generic Viagra delivered directly to your door starting at $18 per month.
Several medications are available to treat erectile dysfunction (ED). But Viagra (sildenafil) is likely the one you’ve heard about most. It was the first phosphodiesterase-5 (PDE5) inhibitor to be FDA approved for ED, and it’s gone on to become one of the most recognizable medications on the market.
Also known as “the little blue pill,” Viagra helps you achieve and maintain an erection for sex. But if you’re new to taking Viagra, you may be wondering how long it takes for Viagra to work.
Below, we’ll review when to take Viagra — plus four more tips to get the best results.
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You may be asking, “How long before sex should I take Viagra?” Thankfully, not much pre-planning is required. Viagra absorbs quickly into your body.
Viagra can start working within 30 minutes. One study found that about 70% of men taking Viagra achieved an erection in 30 minutes, and more than 80% of men achieved an erection within 45 minutes. But it may take a couple hours for some people.
Overall, Viagra begins to work within 1 hour for most men. However, if you’ve tried taking Viagra multiple times and it doesn’t seem to work at all, talk to your healthcare professional (HCP). They may recommend an alternative ED medication.
Important: Viagra only works when you’re aroused. If you’re not aroused, Viagra likely won’t be an effective ED treatment option for you. This is because PDE5 inhibitors, like Viagra, work by relaxing the smooth muscles and arteries in the penis. This causes more blood to flow to the penis, which helps improve erections.
A persistent effect: Find out how long Viagra stays in your system after it starts working.
Avoiding interactions: Viagra can interact with other medications and foods. Here are the common Viagra interactions you should be aware of.
The alternatives: Beside Viagra, there are several phosphodiesterase 5 (PDE5) inhibitors available to treat erectile dysfunction (ED). Learn about the PDE5 inhibitors used to treat ED and how they compare.
Viagra and its generics are available as 25 mg, 50 mg, and 100 mg tablets.
At first glance, Viagra’s directions may seem straightforward. The recommended starting dose for Viagra is 1 tablet (50 mg) by mouth 1 hour before sexual activity. But depending on your response to the medication, you can take it 30 minutes to 4 hours prior to sexual activity instead.
Other factors can affect how well Viagra works for you, too. You can take Viagra with or without food, but it works best on an empty stomach. When taken with a high-fat meal, its absorption is slower. Food can delay the time it takes Viagra to start working by about an hour.
In other words, if you want Viagra to work more quickly, take it on an empty stomach. If you need to take it with food, consider a light, low-fat meal.
It’s important to know about relevant Viagra interactions with medications and foods before you start taking it. Different interactions cause different reactions.
To avoid any negative side effects, make sure your pharmacist and prescriber have an updated list of all medications and supplements you take. And if you received a Viagra prescription from a HCP other than your primary care physician, make sure to ask them if it’s OK for you to take.
Viagra and other PDE5 inhibitors can lower your blood pressure. It’s best to be cautious if you’re also taking medications that treat high blood pressure. If they’re taken together, your blood pressure may drop too low.
Medications that can interact with Viagra and cause dangerously low blood pressure include:
Alpha blockers, such as tamsulosin (Flomax), alfuzosin (Uroxatral), or doxazosin (Cardura, Cardura XL)
Nitrates, such as nitroglycerin (Nitrostat), isosorbide mononitrate (Monoket), or isosorbide dinitrate (Isordil)
Riociguat (Adempas)
Symptoms of low blood pressure include:
Dizziness
Light-headedness
Shortness of breath
Back pain
Tiredness and fatigue
Try not to combine Viagra with alcohol, either. Alcohol can cause low blood pressure and make ED symptoms worse.
Certain enzymes (proteins) in your liver are responsible for breaking down Viagra. These enzymes can be affected by other medications you may be taking. Some medications can make these enzymes more active, making Viagra less effective. Others can get in their way, which can make Viagra side effects more likely.
Keep an eye out for these medications and substances:
Carbamazepine (Tegretol)
Rifampin (Rifadin)
Certain HIV treatments, such as ritonavir-containing medications
Another brand name of sildenafil, Revatio, is approved for a health condition called pulmonary arterial hypertension. It helps improve blood flow to the lungs. But because Revatio and Viagra contain the same active ingredient, you shouldn’t take them together. The combination can cause more side effects.
Fortunately, if you miss a dose of Viagra, nothing will happen. It’s not a maintenance medication that’s meant to be taken every day. Viagra should only be taken as needed.
However, if you forget to take your dose before engaging in sexual activity, take it as soon as you remember. Don’t double up and take an additional dose of Viagra. This could put you at risk for side effects.
If you find that timing Viagra around your sexual activity isn’t working for you, your prescriber may consider Cialis (tadalafil) as an alternative. Unlike Viagra, some people have the option to take Cialis every day, regardless of sexual activity. In this case, there’s even less pre-planning involved.
Viagra has a number of common side effects, including:
Flushing
Upset stomach
Runny nose
Back pain
Muscle pain
Nausea
Dizziness
Rash
If you experience side effects like these after taking Viagra, talk to your HCP.
Side effects such as headaches and flushing are relatively common, but you should still let them know if they’re bothering you. They may adjust your dose or offer other side effect management tips. But you should contact them right away if any of these side effects become severe or you develop any vision changes.
Viagra can also cause a prolonged erection that won’t go away, known as priapism. If you have an erection that lasts for more than 4 hours after taking Viagra, seek emergency treatment right away. This can cause permanent damage if left untreated.
There are ways to save on Viagra. It’s available as a brand-name medication, but you can also find it as a lower-cost generic. GoodRx can help you navigate ways to save on your prescription.
Save with GoodRx. GoodRx can help you save over 98% off the average retail price of generic sildenafil. Generic sildenafil’s price at certain pharmacies is as low as $14.10 with a free GoodRx discount.
Save with GoodRx Care Direct. Get generic Viagra delivered directly to your door starting at $18 per month.
Save with a copay savings card. If you have commercial insurance and meet eligibility requirements, you can save up to 50% off brand-name Viagra using a savings card from the manufacturer. This card covers up to 12 Viagra prescriptions per year.
Viagra (sildenafil) is an effective option for treating erectile dysfunction (ED). Generally, you should take Viagra about 1 hour before engaging in sexual activity. But this isn’t a hard-and-fast rule. Viagra can start working in as little as 30 minutes for some people, but it can take up to 4 hours for others. If Viagra doesn’t seem to work for you or you’re experiencing side effects, follow up with your prescriber or pharmacist.
Eardley, I., et al. (2002). Onset and duration of action of sildenafil for the treatment of erectile dysfunction. British Journal of Clinical Pharmacology.
Modavar Pharmaceuticals LLC. (2024). Sildenafil tablets [package insert].
Sharma, S., et al. (2023). Hypotension. StatPearls.
Smith, B. P., et al. (2023). Sildenafil. StatPearls.
U.S. Food and Drug Administration. (1998). Drug approval package: Viagra (sildenafil citrate).
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