Viagra Dosage Strengths: NHS Guidelines UK

Understanding Viagra dosage strengths is essential for effective ED treatment. Viagra is available in 25mg, 50mg, and 100mg tablets in the UK, with 50mg being the standard starting dose. The same dosage options apply to sildenafil, the generic alternative. EverydayMeds offers both branded Viagra and generic sildenafil, allowing patients to choose based on preference and budget whilst receiving identical treatment outcomes.

  • 25mg - Lower strength for those sensitive to side effects or taking certain medications
  • 50mg - Standard starting dose recommended by NHS guidelines for most men
  • 100mg - Maximum strength for those who don't respond adequately to lower doses
  • Take only one tablet per 24-hour period, regardless of strength chosen
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.

Complete Guide to Viagra Dosage Strengths

Standard Dosage Options Available

Viagra is manufactured in three distinct strengths: 25mg, 50mg, and 100mg tablets. These same dosages apply to sildenafil, the generic version containing identical active ingredients. At EverydayMeds, patients can select either branded Viagra or cost-effective sildenafil during checkout, with both options requiring the same clinical assessment process.

Starting Dose Recommendations

NHS guidelines typically recommend beginning with 50mg as the standard starting dose for most men with erectile dysfunction. This moderate strength provides an effective balance between therapeutic benefit and minimal side effects. Your prescriber may adjust this based on your medical history, current medications, and cardiovascular health status during the online consultation process.

When Lower Doses Are Prescribed

The 25mg strength may be recommended for men over 65, those with certain medical conditions, or patients taking medications that could interact with sildenafil. This includes men taking alpha-blockers for blood pressure or those with mild liver problems. Starting with a lower dose helps minimise potential side effects whilst still providing therapeutic benefits.

Maximum Strength Considerations

The 100mg dose represents the maximum recommended strength and is only prescribed when lower doses prove insufficient. This strength requires careful consideration of your cardiovascular health, as higher doses may increase the likelihood of side effects such as headaches, flushing, or blood pressure changes. Your prescriber will evaluate whether this strength is appropriate during consultation.

Timing and Administration Guidelines

Regardless of strength chosen, take your tablet 30-60 minutes before planned sexual activity. Effects typically last 4-6 hours, though this doesn't mean maintaining an erection for this duration. Avoid fatty meals before taking your dose, as this may delay effectiveness. Never exceed one tablet within any 24-hour period, irrespective of the strength prescribed.

Choosing Between Branded and Generic

Both Viagra and sildenafil contain identical active ingredients and deliver equivalent therapeutic outcomes. The choice often depends on personal preference and cost considerations. Generic sildenafil typically offers significant savings whilst maintaining the same safety profile and effectiveness as branded Viagra.

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