Sildenafil Citrate: Frequently Asked Questions

Sildenafil citrate is the active ingredient in both branded Viagra and generic sildenafil tablets. As a PDE5 inhibitor, it helps treat erectile dysfunction by increasing blood flow when sexually aroused. This FAQ addresses common questions about dosages, effectiveness, side effects, and eligibility. EverydayMeds offers both branded and generic options following online consultation with UK-licensed prescribers.

  • Available in 25mg, 50mg, and 100mg strengths
  • Works within 30-60 minutes of taking
  • Effects can last 4-6 hours
  • Requires prescription following clinical assessment
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.

Everything You Need to Know About Sildenafil Citrate

How Does Sildenafil Citrate Work?

Sildenafil citrate blocks the PDE5 enzyme, allowing increased blood flow to the penis during sexual arousal. It does not cause automatic erections - sexual stimulation is still required. The medication typically works within 30-60 minutes and effects may last 4-6 hours, though this does not mean erections last this duration.

Dosage and Administration

Sildenafil is available in 25mg, 50mg, and 100mg tablets. The typical starting dose is 50mg, taken approximately one hour before sexual activity. Based on effectiveness and tolerability, your prescriber may adjust this to 25mg or increase to 100mg. Only take one dose per 24-hour period. Food, particularly fatty meals, may delay the onset of action.

Who Can Take Sildenafil Citrate?

Adult men over 18 with erectile dysfunction may be suitable candidates. A clinical assessment evaluates your cardiovascular health, current medications, and medical history. You must complete an online consultation with a UK-licensed prescriber before treatment. The medication is not suitable for women or those under 18 years.

Important Safety Considerations

Sildenafil should never be taken with nitrates (such as GTN spray) due to dangerous blood pressure interactions. It is also contraindicated with severe heart disease, recent heart attack or stroke, severe liver problems, or very low blood pressure. Always disclose all medications and health conditions during your consultation.

Branded vs Generic Options

EverydayMeds offers both Viagra (branded) and sildenafil (generic) containing the same active ingredient - sildenafil citrate. Both undergo identical clinical assessments and have equivalent effectiveness. Patients can choose their preferred option during checkout, with generic typically offered at a lower cost whilst maintaining the same quality and safety standards.

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