Sildenafil vs Viagra UK: Which ED Treatment Is Best?

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Sildenafil vs Viagra: Comparing Your ED Treatment Options

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Pricing Disclaimer: Prices on some pages may not be up to date — the live pricing table below and pricing shown during consultation are official current prices and take precedence over any other figures on the site.

Sildenafil - UK-licensed prescription Treatment
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Sildenafil

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Tadalafil - UK-licensed prescription Treatment
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Tadalafil

From £9.99

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Sildenafil Eropid - UK-licensed prescription Treatment
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Sildenafil Eropid

From £8.99

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Tadalafil (Teva) - UK-licensed prescription Treatment
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Tadalafil (Teva)

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Avarante Tablets Tadalafil Tablets 10mg - UK-licensed prescription Treatment
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Avarante Tablets Tadalafil Tablets 10mg

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Viagra Connect 50mg - UK-licensed prescription Treatment
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Understanding Sildenafil vs Viagra: Active Ingredient, Efficacy and Cost

Published on: June 03, 2026

When comparing sildenafil vs viagra uk options, many patients are surprised to learn they contain the exact same active pharmaceutical ingredient at identical concentrations. At Cured Pharmacy, we dispense both branded Viagra and generic sildenafil following a free online consultation with UK prescribers, with sildenafil available from just £0.45 per tablet.

Sildenafil vs Viagra: What's the Actual Difference?

Viagra and sildenafil are pharmaceutically identical medications. Viagra is the brand name manufactured by Pfizer, whilst sildenafil is the generic version produced by multiple licensed manufacturers after Pfizer's patent expired in 2013 [1]. Both contain sildenafil citrate as the active ingredient, available in 25mg, 50mg, and 100mg doses.

The chemical composition, mechanism of action, absorption rate, and clinical efficacy are identical between branded Viagra and generic sildenafil [1]. Both work by inhibiting phosphodiesterase type 5 (PDE5), an enzyme that regulates blood flow to the penis. This inhibition allows increased blood flow during sexual stimulation, helping achieve and maintain an erection suitable for intercourse.

In clinical trials, both formulations demonstrated similar efficacy rates, with approximately 74% of men experiencing improved erectile function at the 100mg dose [2]. The primary differences lie in packaging, manufacturer, and cost — not therapeutic effect.

How Sildenafil and Viagra Work for Erectile Dysfunction

Sildenafil citrate — whether branded as Viagra or dispensed as generic sildenafil — belongs to the PDE5 inhibitor class of medications licensed by the MHRA for erectile dysfunction treatment [1]. When a man is sexually aroused, nitric oxide is released in the erectile tissue, triggering a cascade that produces cyclic guanosine monophosphate (cGMP).

This cGMP causes smooth muscle relaxation in the penile arteries, allowing increased blood flow. PDE5 naturally breaks down cGMP, limiting the duration of erections. By inhibiting PDE5, sildenafil allows cGMP levels to remain elevated longer, supporting sustained erections during sexual activity [2].

Both medications typically take effect within 30-60 minutes of ingestion and remain active for approximately 4-6 hours [2]. They require sexual stimulation to work — sildenafil does not cause spontaneous erections. Food, particularly high-fat meals, may delay absorption and reduce peak effectiveness.

Optimal Timing and Dosing

Most UK prescribers recommend taking sildenafil or Viagra approximately one hour before planned sexual activity on an empty stomach for optimal absorption. The standard starting dose is 50mg, which can be adjusted to 25mg or increased to 100mg based on individual response and tolerability [3]. Your prescriber will determine the appropriate dose during your clinical assessment at Cured Pharmacy.

Cost Comparison: Sildenafil vs Viagra Pricing in the UK

The most significant practical difference between sildenafil and Viagra is cost. At Cured Pharmacy, generic sildenafil starts from just £0.45 per tablet, whilst branded Viagra Connect begins at a higher price point due to brand premium and marketing costs.

This substantial price difference exists despite identical therapeutic profiles. When Pfizer's patent protection expired in 2013, multiple pharmaceutical manufacturers gained approval to produce generic versions, increasing market competition and dramatically reducing costs [1]. The generic manufacturers don't bear the research, development, and marketing expenses that Pfizer invested in the original branded product.

For patients requiring ongoing ED treatment, choosing generic sildenafil over branded Viagra can result in considerable annual savings without any compromise in clinical efficacy or safety. All generic sildenafil dispensed by Cured Pharmacy is manufactured to the same rigorous UK pharmaceutical standards and undergoes identical quality control processes as branded alternatives.

Transparent Pricing Before Consultation

Unlike many online pharmacies, Cured Pharmacy displays upfront pricing before you begin your clinical assessment. You'll see exactly what you'll pay with no hidden fees or surprise charges after your consultation. Our lowest prices guaranteed policy ensures you're getting competitive UK pricing on genuine licensed medications.

Feature Generic Sildenafil Branded Viagra
Active Ingredient Sildenafil citrate Sildenafil citrate
Available Strengths 25mg, 50mg, 100mg 25mg, 50mg, 100mg
Time to Effect 30-60 minutes 30-60 minutes
Duration of Action 4-6 hours 4-6 hours
Clinical Efficacy ~74% at 100mg dose ~74% at 100mg dose
Starting Price From £0.45 From £11.49
Prescription Required Yes Yes
MHRA Licensed Yes Yes

Efficacy and Side Effects: Are They Different?

Clinical studies confirm that generic sildenafil and branded Viagra demonstrate bioequivalence — meaning they produce the same blood concentration levels over the same time period when administered at identical doses [1]. In practical terms, a 50mg sildenafil tablet will produce the same therapeutic effect as a 50mg Viagra tablet.

The side effect profiles are also identical. Common side effects include headache (reported by approximately 16% of users), facial flushing (10%), dyspepsia (7%), and nasal congestion (4%) [2]. These effects are generally mild to moderate and resolve within a few hours. Serious adverse events are rare but can include sudden vision or hearing loss, priapism (prolonged erection lasting over 4 hours), and cardiovascular events in predisposed individuals.

Both medications carry the same contraindications and drug interactions. They must not be taken with nitrate medications (commonly prescribed for angina) due to risk of severe hypotension [3]. Patients taking alpha-blockers, certain antifungals, or HIV protease inhibitors may require dose adjustments. Your UK prescriber will review your medical history and current medications during your online consultation to ensure safe prescribing.

Which Should You Choose: Sildenafil or Viagra?

From a purely clinical perspective, there is no therapeutic advantage to choosing branded Viagra over generic sildenafil. Both medications contain the same active ingredient at identical concentrations and produce equivalent clinical outcomes [1]. The decision often comes down to personal preference and budget considerations.

Some patients prefer branded Viagra due to familiarity with the name or confidence in the original manufacturer. Others appreciate the substantial cost savings offered by generic sildenafil without any compromise in efficacy or safety. Both options are equally valid choices for ED treatment, subject to prescriber approval following clinical assessment.

At Cured Pharmacy, our UK-registered prescribers will discuss both options during your free online consultation. We dispense only genuine UK-licensed medications from MHRA-approved manufacturers, whether you choose branded or generic treatment. Your prescription will be based on your medical history, current medications, and individual treatment goals.

Switching Between Viagra and Sildenafil

Patients can safely switch between branded Viagra and generic sildenafil at equivalent doses without any adjustment period or loss of efficacy. If you've been taking 50mg Viagra successfully, you can transition to 50mg sildenafil and expect the same therapeutic response. Always consult your prescriber before making changes to your treatment regimen.

Getting Sildenafil or Viagra Online from Cured Pharmacy

All sildenafil and Viagra products at Cured Pharmacy require a prescription following clinical assessment by a UK-registered prescriber. Our online consultation takes under three minutes and covers your medical history, current medications, cardiovascular health, and treatment expectations. This ensures safe, appropriate prescribing in compliance with MHRA and GPhC regulations.

Once approved, your medication is dispensed by our UK-registered pharmacy team under the supervision of Superintendent Pharmacist Tarun Kumar (GPhC 2233073). We offer discreet packaging and reliable delivery across the UK, with your medication arriving in plain, unmarked packaging that protects your privacy.

We stock multiple sildenafil formulations including standard generic sildenafil tablets and Sildenafil Eropid, giving you options to suit your preferences and budget. Our transparent pricing means you'll see the exact cost before starting your consultation — no hidden fees or surprise charges. If you have questions about which option is right for you, our clinical team is available on (+44) 116 4646009.

Scientific References

  1. Medicines and Healthcare products Regulatory Agency. (2020). Sildenafil: Drug Safety Update. GOV.UK. https://www.gov.uk/drug-safety-update/sildenafil-viagra-reminder-of-cardiovascular-risk [accessed 13 August 2026]
  2. Goldstein, I., et al. (1998). Oral sildenafil in the treatment of erectile dysfunction. New England Journal of Medicine, 338(20), 1397-1404. https://doi.org/10.1056/NEJM199805143382001 [accessed 13 August 2026]
  3. British National Formulary. (2024). Sildenafil. BNF Publications. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 13 August 2026]
  4. European Medicines Agency. (2013). Assessment report for sildenafil containing medicinal products. EMA/CHMP/14796/2013. https://www.ema.europa.eu/en/documents/referral/sildenafil-article-31-referral-chmp-assessment-report_en.pdf [accessed 13 August 2026]
  5. NHS. (2026). Erectile dysfunction (impotence). https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ Accessed 13 August 2026.

Information on this page is for educational purposes only and is not medical advice. All prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting any new medication.

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Faq

Is sildenafil as effective as Viagra?
Yes, generic sildenafil is pharmaceutically identical to branded Viagra and produces the same clinical efficacy. Both contain sildenafil citrate at identical concentrations and demonstrate bioequivalence in clinical studies.
Why is sildenafil cheaper than Viagra?
Sildenafil costs less because generic manufacturers don't bear the research, development, and marketing expenses that Pfizer invested in branded Viagra. After patent expiry in 2013, competition among multiple licensed manufacturers reduced prices whilst maintaining identical quality standards.
Can I switch from Viagra to sildenafil?
Yes, you can safely switch between branded Viagra and generic sildenafil at equivalent doses without any adjustment period or loss of efficacy. Always consult your UK prescriber before making changes to your treatment.
How long does sildenafil vs Viagra last?
Both sildenafil and Viagra remain active in your system for approximately 4-6 hours after ingestion. The duration of action is identical because they contain the same active pharmaceutical ingredient at the same concentrations.
Does sildenafil have the same side effects as Viagra?
Yes, generic sildenafil and branded Viagra have identical side effect profiles. Common effects include headache, facial flushing, dyspepsia, and nasal congestion, occurring at the same frequencies.
Do I need a prescription for sildenafil or Viagra?
Yes, both sildenafil and Viagra are prescription-only medications in the UK. At Cured Pharmacy, you'll complete a free online consultation with a UK-registered prescriber who will assess your suitability before prescribing.
Which is better for erectile dysfunction: sildenafil or Viagra?
Neither is clinically superior — they contain identical active ingredients and produce equivalent therapeutic outcomes. The choice typically depends on personal preference and budget, with sildenafil offering substantial cost savings.
How quickly do sildenafil and Viagra work?
Both medications typically take effect within 30-60 minutes when taken on an empty stomach. High-fat meals may delay absorption and reduce peak effectiveness for both formulations.
Tarun Kumar, Prescribing Pharmacist

Medically reviewed by

Tarun Kumar, Prescribing Pharmacist (GPhC 2233073)

Reviewed on: June 03, 2026

Last reviewed: 13 August 2026

Last updated on 13 August 2026.

Review History

Our experts continually monitor new findings in health and medicine, and we update our articles when new information becomes available.

Why this page was updated on 13 August 2026

Content checked and updated as part of our periodic review, to ensure accuracy and currentness.

Current version (13 August 2026)

Edited by: The Editorial Team

Medically reviewed by:

Tarun Kumar, GPhC No. 2233073, Prescribing Pharmacist


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