Viagra 100mg: Essential Quick Reference Guide

Viagra 100mg contains sildenafil citrate and is prescribed for erectile dysfunction in adult men. This comprehensive quick reference covers dosage, effectiveness, safety considerations and eligibility criteria. EverydayMeds offers both branded Viagra and generic sildenafil options through our online consultation service. All treatments require prescription following assessment by UK-licensed prescribers. Understanding key facts helps ensure safe and effective use.

  • Take one tablet 30-60 minutes before sexual activity
  • Maximum one dose per 24 hours - never exceed this limit
  • Works for 4-6 hours but requires sexual arousal
  • Available as branded Viagra or generic sildenafil
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Not sure which one? Here's the honest comparison.

Sildenafil
~60 min
~4 hrs
you like to plan ahead
Explore now
Tadalafil (as-needed)Most prescribed
~30 min
up to 36 hrs
you want a whole weekend covered
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Tadalafil Daily
always active
continuous
you never want to think about timing
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Vardenafil
~15–30 min
~8 hrs
you want the fastest onset
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How ED treatment works in your body.

Increases blood flow

Increases blood flow

When PDE5 is suppressed, blood is able to flow more freely through the body—including to the (you guessed it) penis.

Increase erections

Increase erections

More blood flow to the penis means harder, more satisfying erections once you're sexually stimulated.

Complete Viagra 100mg Treatment Information

How Viagra 100mg Works

Viagra 100mg contains sildenafil citrate, a PDE5 inhibitor that increases blood flow to the penis during sexual arousal. The medication does not cause automatic erections - sexual stimulation remains necessary. Effects typically begin within 30-60 minutes and may last 4-6 hours, though individual response varies. EverydayMeds offers both branded Viagra and generic sildenafil containing the same active ingredient.

Dosage and Administration

Viagra 100mg represents the maximum recommended dose. Many patients start with 50mg, with dosage adjusted based on effectiveness and tolerability. Take one tablet with water approximately one hour before sexual activity. Fatty meals may delay onset of action. Never take more than one dose in 24 hours, regardless of effectiveness. Your prescriber will determine the most suitable starting dose during consultation.

Eligibility and Safety Considerations

Viagra 100mg requires prescription following clinical assessment. The medication is suitable for adult men with erectile dysfunction who meet specific health criteria. Patients taking nitrates, those with severe cardiovascular disease, or recent stroke/heart attack history typically cannot use sildenafil safely. EverydayMeds prescribers evaluate medical history, current medications and cardiovascular health before prescribing.

Side Effects and Precautions

Common side effects may include headache, facial flushing, indigestion or nasal congestion. These are typically mild and temporary. Serious side effects are rare but require immediate medical attention, including prolonged erections lasting over four hours or sudden vision/hearing changes. Patients should inform prescribers about all medications, particularly blood pressure treatments, as interactions may occur.

Choosing Between Viagra and Generic Sildenafil

EverydayMeds patients can choose between branded Viagra and generic sildenafil at checkout. Both contain identical active ingredients and work identically, with generic options typically costing less. The choice between branded and generic is purely personal preference - effectiveness and safety profiles are equivalent. All treatments undergo the same rigorous consultation process with UK-licensed prescribers.

What you need to know about erectile dysfunction

It's one of the most common conditions we treat, and one of the most treatable.

What is Erectile Dysfunction?
ED means finding it hard to get or keep an erection firm enough for sex. It's not unusual to have an off night; the point at which it's worth doing something is when it's happening regularly, or when it's starting to bother you.
How will I feel when I take ED medication?
For most men, nothing feels different day to day. The medication works in the background — when you're sexually aroused, it helps blood flow where it's needed, so erections come more easily and last longer. It doesn't cause arousal on its own. Some men notice mild, short-lived effects like a headache, facial flushing or a stuffy nose, which usually pass as the dose wears off.
Why do I need a prescription for ED medication?
ED treatments are prescription-only medicines in the UK because they aren't suitable for everyone — for example, alongside certain heart conditions or medications like nitrates. That's why we ask you to complete a short online consultation first. A UK-registered prescriber reviews your answers to make sure your chosen treatment is safe and right for you before it's dispensed.
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