Erectile Dysfunction

Sildenafil (Generic Viagra)

ED treatment that works in under an hour, in the strength that fits you.

Sildenafil is an FDA-approved PDE5 inhibitor that relaxes blood vessels to support an erection once you're aroused. It starts working in 30 to 60 minutes and stays effective for up to 6 hours, available in 50mg and 100mg so you can choose the strength that fits your response.

Oral tablet50 / 100 mg

Strength

Doses per month

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Cadence

Sildenafil 50mg - 10 Doses/Month Monthly Plan - 10 doses/mo$62 billed monthly

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How it works

How Sildenafil (Generic Viagra) works

Sildenafil is classified as a PDE5 inhibitor. This class works by inhibiting the enzyme that degrades cGMP, allowing smooth muscle in the penis to relax and blood flow to increase once stimulation begins. Without arousal, sildenafil produces no erectile response on its own. The mechanism is identical at 50mg and 100mg; the higher dose simply delivers more active drug for people whose response to 50mg wasn't strong enough. Choose your strength, 50mg or 100mg, at checkout.

What to expect

Timeline & results

Onset generally falls within a 30 to 60 minute window, with peak concentration reached around the one-hour mark and effectiveness extending 4 to 6 hours from that point, the same timeline at either strength. A high-fat meal slows gastric absorption, which can delay onset to approximately 2 hours after dosing. 100mg is the highest FDA-approved dose, with no added benefit beyond it, and it's generally reserved for people who didn't get enough effect from 50mg.

Getting started

Care that fits your life

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Answer a few health questions, 100% online, no appointment needed.

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Key benefits

What Sildenafil (Generic Viagra) is used for

Reaches peak concentration in about an hour, faster than tadalafil's roughly two-hour peak.

Provides a 4 to 6 hour window suited to a single planned evening, at either strength.

100mg available for people whose response to 50mg wasn't strong enough, with no added benefit above it.

Priced among the most affordable ED prescriptions available.

Backed by more than 25 years of documented clinical use since its 1998 FDA approval.

Safety information

Important safety information

Sildenafil requires sexual arousal to work; it does not cause spontaneous erections. Never take sildenafil with nitrate medications. This combination can cause a dangerous drop in blood pressure. Reported side effects, generally mild, include nasal congestion, dyspepsia, flushing, a temporary blue tinge to vision, and headache, somewhat more common at 100mg than at 50mg. Before prescribing, a provider will also evaluate for alpha-blocker use, CYP3A4-inhibiting medications, a stroke or recent heart attack, uncontrolled high blood pressure, a history of NAION (a rare eye condition affecting the optic nerve), and broader cardiovascular disease.

This page is educational and is not medical advice. Tell your provider about your full medical history and current medications before starting treatment.

About

About Sildenafil (Generic Viagra)

Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor and the active ingredient in the first oral medication approved by the FDA for erectile dysfunction. It works by selectively blocking the PDE5 enzyme in penile vascular smooth muscle, which prevents the degradation of cyclic GMP (cGMP). The resulting increase in cGMP promotes smooth muscle relaxation and vasodilation, increasing blood flow to erectile tissue when sexual stimulation is present. Like all PDE5 inhibitors, sildenafil is not an aphrodisiac. Sexual arousal remains necessary for the mechanism to produce its intended effect.

Sildenafil is typically taken approximately 30 to 60 minutes before anticipated sexual activity. A provider may prescribe a starting dose of 50 mg or 100 mg based on a review of your health history, other medications, and treatment goals. The availability of multiple dose strengths allows for individualized titration under provider guidance. The medication's effects generally last 4 to 6 hours, making it well-suited for planned encounters.

Onset can be influenced by a high-fat meal, which may delay absorption. Taking sildenafil on an empty stomach or after a light meal is generally associated with a more predictable time to effect. Individual response, including time to onset and duration, can vary between patients.

Sildenafil may be a good fit for men who prefer to time their dose around specific activity and are comfortable with a defined, shorter window. It is one of the most extensively studied medications in this class and has been used by millions of men worldwide. It is available through a licensed pharmacy as a compounded tablet after a provider review of your suitability.

Common side effects include headache, flushing, nasal congestion, visual disturbances (such as a blue-tinged tint or light sensitivity), and dyspepsia. Sildenafil is contraindicated in combination with nitrate medications (e.g., nitroglycerin, isosorbide) and guanylate cyclase stimulators due to the risk of severe hypotension. Patients with significant cardiovascular disease, uncontrolled hypertension, or those taking alpha-blockers should disclose their full medical history during the provider consultation.

FAQ

Frequently asked questions

Should I start with 50mg or 100mg sildenafil?+

Most people start at 50mg, moving up to 100mg only if that dose isn't strong enough. There's no added benefit beyond 100mg, and side effects such as headache and flushing are somewhat more common at that strength. Choose your starting strength at checkout; a provider can help confirm which one fits your health history.

How long does sildenafil take to work?+

Sildenafil typically starts working within 30 to 60 minutes of taking it, with peak effect around the one-hour mark, the same timeline at 50mg or 100mg. It stays effective for roughly 4 to 6 hours. Taking it after a high-fat meal can slow absorption and push onset closer to 2 hours, so many people take it on a lighter stomach for faster, more predictable results.

How is sildenafil different from Viagra?+

Sildenafil is the active ingredient in brand-name Viagra, so the two work identically at matching strengths. Both are FDA-approved for erectile dysfunction and rely on increased blood flow during arousal to work. The main difference is cost. Sildenafil is sold as a generic, which is typically far less expensive than brand-name Viagra for the same medication.

Is sildenafil safe to take with heart medication?+

Sildenafil is not safe to combine with nitrate medications, often prescribed for chest pain, since the combination can cause a dangerous drop in blood pressure. If you take other heart medications, such as alpha-blockers, or have cardiovascular disease, a recent heart attack or stroke, or uncontrolled high blood pressure, your provider needs to review your history before prescribing sildenafil at either strength.

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