Viagra & Sildenafil Dosage Strengths Guide

Understanding the correct dosage strengths for Viagra and sildenafil is essential for safe, effective ED treatment. Both medications contain the same active ingredient but are available in multiple strengths to suit individual needs. This guide covers the standard dosages, starting recommendations, and how to adjust treatment based on response and tolerability.

  • Three standard strengths available: 25mg, 50mg, and 100mg tablets
  • Starting dose typically 50mg, taken 30-60 minutes before sexual activity
  • Maximum one dose per 24-hour period for safety
  • Dosage can be adjusted up or down based on effectiveness and side effects
Start your free consultation

Takes less than 2 minutes to complete, 100% online

More pleasure. Less waiting. Built to last.

Get Started

Not sure which one? Here's the honest comparison.

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

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.

Available Dosage Strengths and Clinical Guidance

Standard Dosage Strengths Available

Both Viagra (branded) and sildenafil (generic) are available in three standardised strengths: 25mg, 50mg, and 100mg tablets. EverydayMeds offers both options, allowing patients to choose between the branded Viagra or the more cost-effective generic sildenafil at checkout. The active ingredient and clinical effectiveness remain identical between both formulations.

Recommended Starting Dose

The MHRA-approved starting dose for most adult men is 50mg, taken approximately 30-60 minutes before anticipated sexual activity. This middle-strength dose provides an effective balance between therapeutic benefit and potential side effects. Clinical studies demonstrate that 50mg is sufficient for many patients to achieve satisfactory results whilst minimising adverse reactions.

Dose Adjustment Guidelines

Based on individual response and tolerability, the dose may be adjusted. If 50mg proves insufficient and is well-tolerated, the dose can be increased to 100mg (maximum strength). Conversely, if side effects occur or the patient is particularly sensitive, the dose can be reduced to 25mg. Factors influencing dosage requirements include age, overall health status, concurrent medications, and individual metabolism.

Important Dosing Safety Rules

Regardless of strength chosen, never exceed one dose within a 24-hour period. Taking multiple doses can lead to dangerous drops in blood pressure and serious cardiovascular complications. The medication should be swallowed whole with water and can be taken with or without food, though fatty meals may delay onset of action.

Special Dosing Considerations

Patients over 65 years or those with liver or kidney impairment typically require lower starting doses, often beginning with 25mg. Similarly, individuals taking certain medications such as alpha-blockers or some antifungals may need dose adjustments. Always complete a thorough medical assessment to determine the most appropriate starting strength for your individual circumstances.

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.
Couple laughing together

How it works

Achieve your goals in just a few simple steps.

Step 1

Start Free Consultation

Select safe UK treatments. Quick answers.

Step 2

Review By Our Clinical Team

Our expert team will use your consultation as the basis of our recommendation and communicate with you.

Step 3

Get it delivered fast

We’ll deliver direct to you, as quickly as tomorrow.

Frequently asked questions