Sildenafil FAQ: Your Questions Answered

Looking for quick answers about sildenafil treatment? This comprehensive FAQ addresses the most common questions patients have about sildenafil, from how it works to dosage guidance and potential side effects. Whether you're considering generic sildenafil or comparing it with branded Viagra, you'll find essential information to help inform your treatment decisions. All sildenafil treatments require a prescription following consultation with a UK-licensed prescriber, and EverydayMeds offers both generic sildenafil and branded Viagra options at checkout.

  • Essential dosage and timing information for sildenafil treatment
  • Common side effects and when to seek medical advice
  • Important drug interactions and safety considerations
  • Differences between generic sildenafil and branded Viagra options
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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.

Essential Sildenafil Information at Your Fingertips

How Does Sildenafil Work?

Sildenafil belongs to a class of medicines called PDE5 inhibitors, which work by increasing blood flow to the penis when sexually aroused. It's important to understand that sildenafil doesn't cause automatic erections - sexual stimulation is still required for the medication to be effective. The treatment blocks the phosphodiesterase type 5 enzyme, allowing blood vessels to relax and improve circulation during arousal.

Many patients ask about onset time and duration. Sildenafil typically begins working within 30-60 minutes of taking the tablet, with effects potentially lasting 4-6 hours. This doesn't mean an erection will last this long, but rather that the medication remains active in your system during this timeframe.

What Dosages Are Available?

Sildenafil is available in three strengths: 25mg, 50mg, and 100mg tablets. Most patients start with the 50mg dose, which can then be adjusted based on effectiveness and how well the medication is tolerated. Your prescriber may recommend a lower 25mg dose if you experience side effects, or increase to 100mg if the standard dose isn't sufficiently effective.

The maximum dosage is one tablet per 24-hour period, regardless of strength. Taking sildenafil 30-60 minutes before planned sexual activity typically provides optimal results. EverydayMeds offers both generic sildenafil and branded Viagra in all three strengths, allowing patients to choose their preferred option during checkout.

Who Can Take Sildenafil?

Sildenafil is suitable for adult men aged 18 and over who have erectile dysfunction. However, it's not appropriate for everyone. The medication requires a prescription following clinical assessment by a UK-licensed prescriber, who will evaluate your medical history, current medications, and cardiovascular health to ensure safe treatment.

Certain medical conditions may make sildenafil unsuitable, including severe heart disease, recent heart attack or stroke (within six months), severe liver problems, very low blood pressure, or hereditary retinal disorders. Additionally, men taking nitrate medications for chest pain cannot use sildenafil due to dangerous drug interactions.

What Are the Common Side Effects?

The most frequently reported side effect is headache, experienced by more than one in ten patients. Other common side effects include facial flushing, indigestion, nasal congestion, dizziness, mild visual disturbances (such as a blue tinge to vision), and nausea. These effects are typically mild and temporary, often becoming less noticeable with continued use.

Serious side effects are rare but require immediate medical attention. These include priapism (a painful erection lasting more than four hours), sudden vision or hearing loss, chest pain during sexual activity, or signs of severe allergic reaction. If you experience any concerning symptoms, seek medical help promptly.

Important Drug Interactions

Some medications cannot be safely combined with sildenafil. Never take sildenafil if you're using nitrate medications like glyceryl trinitrate (GTN spray) or isosorbide, as this combination can cause dangerous drops in blood pressure. Recreational drugs containing nitrates (often called "poppers") also pose serious risks when combined with sildenafil.

Other medications require careful monitoring when used alongside sildenafil, including alpha-blockers for prostate problems, certain blood pressure medications, HIV treatments, and some antibiotics or antifungals. Always inform your prescriber about all medications you're taking, including over-the-counter medicines and supplements.

Sildenafil vs Viagra: Understanding Your Options

Generic sildenafil and branded Viagra contain the same active ingredient (sildenafil citrate) and have identical effectiveness and safety profiles. The main difference is cost - generic sildenafil typically costs less whilst providing the same therapeutic benefits. Some patients prefer branded Viagra for personal reasons, whilst others choose generic sildenafil for value.

Both options require the same prescription process and clinical assessment. EverydayMeds provides the flexibility to choose between generic sildenafil and branded Viagra during your order, ensuring you receive your preferred treatment option.

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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