Is It OK to Take 100mg of Sildenafil?

Sildenafil is one of the best-known medications for managing erectile dysfunction (ED) — and not just because it was the first erectile dysfunction drug on the scene back in 1998. Most people are familiar with the brand-name version, Viagra®. But the medication is also sold as a generic drug simply called sildenafil.

Is it OK to take 100mg of sildenafil? It’s usually safe to take 100mg (milligrams) of sildenafil when your healthcare provider prescribes that dose. Sildenafil is sold in tablets ranging from 25 to 100mg. Your provider will determine which dose is best for you before they write you a prescription. Often, men will start on a 50mg dose and adjust as needed.

Keep reading to learn more about who may benefit from taking 100mg of sildenafil, as well as the potential risks, drug interactions, and other considerations.

Sildenafil (with the active ingredient sildenafil citrate) is available in various doses. Currently, 100mg is the highest dose of sildenafil approved by the FDA (U.S. Food and Drug Administration) for treating erectile dysfunction.

Taking a 100mg dose of sildenafil is usually OK if that’s the amount your medical provider tells you to take. You shouldn’t exceed your provider’s recommended dosage.

How Sildenafil Starting Doses Are Determined

Your provider will likely only prescribe a 100mg dose if you’ve already tried a lower dose of sildenafil and it hasn’t been effective. The usual starting dose is 50mg, which can be lowered to 25mg.

Your healthcare provider may also start treatment for ED with the 100mg dosage if you have severe symptoms. For example, if it’s particularly difficult to get an erection, even with substantial sexual stimulation, or if you’re never able to get an erection.

A healthcare professional might also consider how often you have sex. Your dosage may be adjusted if you have sex frequently and take sildenafil very often — or if you only take this medication once every few days for less frequent sexual intercourse.

How much sildenafil is too much? Get answers in our blog.

What Else Is Sildenafil Used For?

Sildenafil was originally developed to treat angina (chest pain) and hypertension (high blood pressure). In the early ‘90s, researchers discovered that it may make an effective treatment for erectile dysfunction.

Along with ED, sildenafil has been used off-label as a treatment for:

• Raynaud’s phenomenon (decreased blood flow to the extremities, causing coldness and numbness)

• Female sexual arousal disorder

• Altitude-induced hypoxemia (lack of sufficient oxygen in the blood in high altitudes)

Off-label use is when a drug is prescribed by a licensed healthcare provider to treat something it’s not FDA-approved for — this is legal and common.

The dosages of sildenafil are typically different when treating these other health conditions. Learn more in our sildenafil dosages guide.

Sildenafil works well for most men with erectile dysfunction at any dosage. However, the highest 100mg dosage produces improvements for a higher percentage of men than 50 or 25mg. The downside is that 100mg also generally causes more side effects.

If you have mild or moderate ED, your healthcare provider will likely prescribe 50mg of sildenafil as your starting dose. This is the typical go-to oral dose for sildenafil — for many men, it’s enough to treat erectile dysfunction and improve sexual performance.

The 100mg dose of sildenafil is generally safe if that’s what your provider prescribed. But everyone’s tolerability is different.

In some cases, 100mg may be too much. And even those who start on the 50mg dose might go down to 25mg of sildenafil if they’re experiencing unmanageable side effects.

In clinical trials, researchers found that 82 percent of men with ED reported some improvements in erectile function after using sildenafil at a dosage of 100mg.

In the same trials, 74 percent and 63 percent of men reported improvements with 50mg and 25mg of sildenafil, respectively.

Other clinical trials have suggested that doses above 100mg don’t improve the effectiveness of the medication but do increase side effects.

Sildenafil at any dosage takes roughly 30 to 60 minutes to start working, so you should try to take it an hour or so before sexual activity.

That might mean slipping away into the bathroom after you’ve paid the bill or being sneaky on your way back to the car. The point is, you don’t want to take sildenafil 10 minutes before your clothes come off — it needs a little more time to do its thing in your system.

Once you take the pill, sildenafil can be effective for 30 minutes to four hours, so you have a little wiggle room for planned sexual activity. But, any longer than four hours, and the concentration in your blood might be too low to have a significant effect on your erection quality.

Will You Get an Erection on Sildenafil Without Sexual Arousal?

Sildenafil is a phosphodiesterase type 5 inhibitor, or PDE5 inhibitor. These medications work by inhibiting the PDE5 enzyme, allowing blood vessels in the penis to relax and increasing blood flow to the area.

One critical feature of PDE5 inhibitors is that they only cause erections when you’re feeling in the mood for sex — that is, sexually stimulated physically or mentally. Contrary to popular belief, they won’t cause spontaneous erections (assuming you aren’t thinking about something sexual) or affect your sex drive in any significant way.

This means that if you aren’t sexually aroused, sildenafil won’t kick in at all.

One of the biggest advantages of sildenafil is that it’s an easy medication to use. For the most part, sildenafil can be taken before you plan to have sex without any major concerns.

Having said that, there are a few things you can do to get the best results from it:

• Take sildenafil 100mg around one hour before sex. Sildenafil usually takes about a half-hour to start working. But for optimal results, take your prescribed dose of sildenafil an hour before you plan to have sex in case you metabolize the medication a little slower.

• Avoid high-fat meals while using sildenafil. Eating a meal high in fat may slow down your body’s absorption of sildenafil and delay its effects. Try to eat a normal meal with a low-to-moderate fat content to ensure sildenafil works as expected.

• Don’t panic if sildenafil isn’t effective the first time. A variety of factors can play a role in ED, and sexual performance anxiety is one of them. If you notice sildenafil doesn’t work after a few tries, tell your healthcare provider. They may recommend changing your dose, switching medications, or trying other treatments.

• Combine sildenafil with healthy habits. Simple habits — such as exercising often, eating a balanced diet, and limiting alcohol intake — can all have a positive effect on erections and sexual performance.

• Try to lead a healthy lifestyle. Our guide to maintaining an erection naturally shares techniques to reduce your risk of ED and enjoy better sex.

Learn more about how to take sildenafil in our guide.

Most side effects of sildenafil are mild, and it’s uncommon for them to persist longer than the medication is active in your body.

However, in rare cases, sildenafil treatment can cause more severe or bothersome side effects. Like most medications, side effects are generally more likely at higher doses than lower doses.

For instance, in clinical trials of sildenafil, 16 percent of men reported headaches (the most common side effect) at a dosage of 25mg, compared to 28 percent at 100mg and seven percent who took a placebo.

Common Side Effects of Sildenafil 100mg

Common side effects of sildenafil include:

• Headache

• Flushing

• Dyspepsia (indigestion)

• Vision changes (blurred vision or changes in color perception)

• Nasal congestion

• Myalgia (muscle pain)

• Back pain

• Skin rash

• Nausea

• Dizziness

Our blog goes over all the possible sildenafil side effects in more detail.

Rare Side Effects of Sildenafil 100mg

Although rare, sildenafil can cause more serious side effects that may need immediate medical attention. Possible severe adverse effects include:

• Eye problems like blurred vision or sudden, severe loss of vision

• Sudden hearing loss

• Serious cardiovascular disease — often in people with preexisting risk factors, such as stroke, ventricular arrhythmia (abnormal heartbeat), or heart attack

In very rare cases, sildenafil may also cause priapism — a prolonged and painful erection that may last four hours or longer. Priapism is considered a medical emergency, so seek medical attention as soon as you can to avoid damaging the erectile tissue inside your penis.

With that said, be cautious when taking sildenafil if you have Peyronie’s disease (scar tissue in the penis) or another deformation of the penis that may increase your risk of priapism.

Sildenafil 100mg Drug Interactions

Sildenafil and other PDE5 inhibitor medications can interact with other drugs. In particular, sildenafil is known to interact with:

• Nitrates

• Alpha-blockers

• The calcium-channel blocker amlodipine

• Ritonavir and other CYP3A4 inhibitors, such as the antifungals ketoconazole, itraconazole, and erythromycin

• Alcohol

As such, you shouldn’t take sildenafil or brand-name Viagra if you use nitroglycerin or similar prescription organic nitrates. You also shouldn’t mix sildenafil with recreational drugs called “poppers“ that contain nitrites.

Weirdly, grapefruit juice can change the concentrations of PDE5 inhibitors in your body, so you’ll want to avoid it while taking sildenafil.

Learn more about sildenafil drug interactions in our guide.

Talk to a Healthcare Provider About Sildenafil Adverse Effects

It’s best to seek medical advice from a healthcare professional about any medications or supplements you currently take or have recently taken before starting sildenafil.

Also, be sure to mention any underlying medical conditions you have, including:

• Heart disease

• Heart problems like pulmonary arterial hypertension, angina, or an irregular heartbeat

• A previous cardiovascular event

• A blood disease like leukemia or sickle cell anemia

• Peyronie’s disease

The more you tell your healthcare provider, the better they’ll be able to assess your personal risk of side effects and make sure you’re safe while using sildenafil.

Sildenafil comes in several dosages, but for ED, it ranges from 25 to 100mg. Your healthcare provider may prescribe sildenafil at a dosage of 100mg if you have moderate to severe erectile dysfunction or if you don’t experience any improvements at a lower dosage.

Is it OK to take 100mg of sildenafil? Here’s what to keep in mind:

• Sildenafil might be a more effective ED treatment at higher dosages, but it could also cause more side effects.

• Let your healthcare provider know if you experience any issues while using sildenafil to treat ED, including side effects or drug interactions.

• If you do experience adverse effects with sildenafil that outweigh the benefits of taking it, you may benefit from trying another PDE5 inhibitor, such as Stendra® (avanafil), tadalafil (Cialis®), or vardenafil (previously sold as Levitra®).

We offer sildenafil and several other ED medications online, following an online ED consultation with a licensed healthcare provider who’ll determine if a prescription is appropriate.

Interested in finding out more before you get started? Our guide to the most common treatments for erectile dysfunction goes into detail about the most effective options, from sildenafil to other FDA-approved medications.