Sildenafil is a prescription-only medicine used primarily to treat erectile dysfunction and pulmonary arterial hypertension in the UK. Knowing where to purchase sildenafil legally and safely is essential for ensuring product quality, avoiding counterfeit medicines, and receiving appropriate medical oversight. Legitimate sources include NHS and private GP prescriptions, registered community pharmacies, and General Pharmaceutical Council (GPhC)-registered online services. Viagra Connect 50 mg is also available without prescription following a pharmacist consultation. This article explains how to obtain sildenafil through regulated channels, verify legitimate providers, and understand the serious risks associated with unregulated sources.
Summary: Sildenafil can be legally purchased in the UK with a valid prescription from registered community or online pharmacies, or as Viagra Connect 50 mg from a pharmacist following consultation.
- Sildenafil is a PDE5 inhibitor used to treat erectile dysfunction and pulmonary arterial hypertension by increasing blood flow.
- Most sildenafil products are prescription-only medicines; Viagra Connect 50 mg is available from pharmacists without prescription after assessment.
- Legitimate sources include GPhC-registered pharmacies, NHS GP surgeries, and CQC-registered online prescribing services in England.
- Counterfeit sildenafil from unregulated sources may contain incorrect doses, contaminants, or dangerous ingredients posing serious health risks.
- Sildenafil is contraindicated with nitrates or riociguat due to risk of severe hypotension; medical assessment is essential before use.
- NHS prescriptions are available for erectile dysfunction caused by specific conditions such as diabetes, spinal injury, or prostate cancer treatment.
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What Is Sildenafil and What Is It Used For?
Sildenafil is a medicine classified as a phosphodiesterase type 5 (PDE5) inhibitor. It works by relaxing the smooth muscle in blood vessels, thereby increasing blood flow to specific areas of the body. Most sildenafil products are prescription-only medicines (POM), though Viagra Connect 50 mg is available as a Pharmacy (P) medicine following a pharmacist consultation. The medicine was originally developed to treat cardiovascular conditions but is now primarily prescribed for two main indications in the UK.
Primary licensed uses include:
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Erectile dysfunction (ED) – Sildenafil helps men achieve and maintain an erection sufficient for sexual activity when sexually stimulated. It is marketed under brand names including Viagra and Viagra Connect, as well as generic formulations.
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Pulmonary arterial hypertension (PAH) – At different doses and under specialist supervision, sildenafil is used to treat high blood pressure in the arteries of the lungs, improving exercise capacity and slowing disease progression. PAH products are not interchangeable with ED products.
The mechanism of action involves inhibiting the PDE5 enzyme, which breaks down cyclic guanosine monophosphate (cGMP). By preventing this breakdown, sildenafil allows cGMP levels to remain elevated, promoting vasodilation and improved blood flow. For erectile dysfunction, this effect is localised to the penile tissue when sexual stimulation occurs.
Sildenafil typically begins working within 30–60 minutes of oral administration, with effects lasting approximately four to six hours. High-fat meals may delay onset. It is important to understand that sildenafil does not cause spontaneous erections; sexual arousal is required for the medicine to be effective.
Dosing for erectile dysfunction:
The usual starting dose is 50 mg taken as needed approximately one hour before sexual activity. Depending on effectiveness and tolerability, the dose may be adjusted to 25 mg or increased to a maximum of 100 mg. Do not take sildenafil more than once in 24 hours. The appropriate dose should be determined by a qualified healthcare professional based on individual medical history, concurrent medicines, and response to treatment.
Important safety information:
Sildenafil is contraindicated in patients taking nitrates (e.g. glyceryl trinitrate for angina) or riociguat, as the combination can cause a dangerous drop in blood pressure. It should be used with caution in men with significant cardiovascular disease, severe liver impairment, or low blood pressure. Common side effects include headache, flushing, indigestion, and nasal congestion. Avoid excessive alcohol, which may increase the risk of side effects such as dizziness or low blood pressure.
Seek urgent medical help if you experience:
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An erection lasting more than four hours (priapism)
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Chest pain, severe dizziness, or fainting
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Sudden loss of vision or hearing
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Signs of a severe allergic reaction (difficulty breathing, swelling of the face or throat)
If you have any concerns or experience side effects, speak to your GP or pharmacist. You can report suspected side effects via the MHRA Yellow Card scheme at https://yellowcard.mhra.gov.uk.
Where to Purchase Sildenafil Legally in the UK
In the United Kingdom, most sildenafil products are classified as prescription-only medicines (POM) and can only be legally obtained with a valid prescription from a registered healthcare professional, such as a GP, hospital doctor, or appropriately qualified prescriber. However, Viagra Connect 50 mg is available as a Pharmacy (P) medicine, meaning it can be supplied by a pharmacist without a prescription following a consultation to assess suitability and exclude contraindications.
Legal sources for obtaining sildenafil include:
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Community pharmacies – High-street chemists such as Boots, Lloyds Pharmacy, and independent pharmacies can dispense prescription-only sildenafil with a valid NHS or private prescription. Pharmacists can also supply Viagra Connect 50 mg after a consultation for eligible men aged 18 and over.
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Hospital pharmacies – For patients under specialist care, particularly those being treated for pulmonary arterial hypertension.
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Registered online pharmacies – General Pharmaceutical Council (GPhC)-registered online services that provide remote consultations with UK-registered prescribers and dispense medicines from registered pharmacy premises. In England, providers offering remote prescribing services must also be registered with the Care Quality Commission (CQC). In Scotland, Wales, and Northern Ireland, equivalent regulators are Healthcare Improvement Scotland (HIS), Healthcare Inspectorate Wales (HIW), and the Regulation and Quality Improvement Authority (RQIA), respectively.
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GP surgeries – Some practices operate dispensing services in rural areas where patients can collect medicines directly.
When a pharmacist supplies Viagra Connect 50 mg, they will conduct a consultation to check for contraindications (such as use of nitrates or significant heart disease), assess suitability, and provide advice on safe use. This service is only available to men aged 18 and over who meet specific health criteria.
It is illegal to purchase sildenafil from sources that do not require a prescription or proper medical assessment (except for the lawful pharmacy supply of Viagra Connect 50 mg). The General Pharmaceutical Council (GPhC) regulates all pharmacy premises in the UK, and only registered pharmacies are authorised to supply prescription medicines. Patients should always verify that any pharmacy—whether physical or online—is properly registered and operating within UK law before making a purchase.
NHS Prescriptions vs Private Online Pharmacies
Patients in the UK have two primary routes for obtaining prescription-only sildenafil: through NHS prescriptions or via private services, including regulated online pharmacies. Understanding the differences between these options helps patients make informed decisions about cost, convenience, and clinical appropriateness.
NHS prescriptions are available when erectile dysfunction is caused by specific underlying conditions. According to the NHS Selected List Scheme (SLS), sildenafil may be prescribed on the NHS for men with:
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Diabetes mellitus
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Prostate cancer (including treatment-related ED)
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Spina bifida
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Spinal cord injury
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Multiple sclerosis
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Parkinson's disease
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Poliomyelitis
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Severe pelvic injury or radical pelvic surgery
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Renal failure treated by dialysis or transplant
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Severe distress (as determined by specialist assessment)
NHS prescriptions are typically limited to one treatment per week unless there is exceptional clinical need. For eligible patients, NHS prescriptions incur the standard prescription charge in England (currently £9.90 per item), though exemptions apply for those over 60, on certain benefits, or with medical exemption certificates. In Scotland, Wales, and Northern Ireland, prescriptions are free. However, many men with erectile dysfunction do not meet NHS prescribing criteria and must obtain sildenafil privately.
Private online pharmacies offer an alternative for those ineligible for NHS prescriptions or seeking greater convenience. Legitimate services require patients to complete a detailed medical questionnaire reviewed by a UK-registered prescriber (doctor, pharmacist prescriber, or other independent prescriber). If appropriate, a private prescription is issued and the medicine dispensed from a registered pharmacy.
Private costs vary considerably and are indicative only, typically ranging from approximately £15–£40 for a month's supply, depending on the provider, dosage, and whether branded or generic sildenafil is chosen. Whilst more expensive than NHS prescriptions, private services may offer advantages including discreet home delivery, faster access, and flexible appointment times. Patients should ensure any private service is registered with the General Pharmaceutical Council (GPhC). In England, providers offering remote prescribing services must also be registered with the Care Quality Commission (CQC); equivalent regulators apply in Scotland (HIS), Wales (HIW), and Northern Ireland (RQIA). It is advisable to compare registered providers before making a decision.
How to Verify a Legitimate UK Online Pharmacy
The proliferation of online pharmacies has made accessing medicines more convenient, but it has also created opportunities for illegal operators selling counterfeit or substandard products. Verifying the legitimacy of an online pharmacy is essential for patient safety.
Key verification steps include:
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Check the GPhC register – All legitimate UK pharmacies must be registered with the General Pharmaceutical Council. Visit www.pharmacyregulation.org and use the 'Find a pharmacy' tool to confirm registration. Each registered pharmacy has a unique registration number displayed on its website.
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Look for the GPhC internet pharmacy logo – Legitimate online pharmacies in Great Britain display the GPhC internet pharmacy logo. Clicking this logo should link directly to the pharmacy's entry on the GPhC public register. (Note: In Northern Ireland, the EU common logo may still be relevant.)
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Verify prescriber credentials – Legitimate services will clearly identify the prescribers conducting consultations, who must be registered with the General Medical Council (GMC), General Pharmaceutical Council (GPhC), or Nursing and Midwifery Council (NMC) for independent prescribers. You can verify registration at www.gmc-uk.org, www.pharmacyregulation.org, or www.nmc.org.uk.
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Assess the consultation process – Reputable online pharmacies require comprehensive medical questionnaires covering medical history, current medicines, and contraindications. Be wary of services that offer prescriptions with minimal or no health assessment.
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Check for a physical address – Legitimate pharmacies provide a verifiable UK address and contact details, including a telephone number for patient queries.
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Confirm provider registration – In England, services offering remote prescribing must be registered with the Care Quality Commission (CQC). Equivalent regulators apply in Scotland (Healthcare Improvement Scotland, HIS), Wales (Healthcare Inspectorate Wales, HIW), and Northern Ireland (Regulation and Quality Improvement Authority, RQIA).
Warning signs of illegitimate operators include:
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No prescription requirement or superficial health checks
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Prices significantly below market rates
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Spelling errors, poor website design, or unprofessional presentation
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Lack of clear contact information or regulatory registration details
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Unsolicited emails offering medicines
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Claims of "miracle cures" or guaranteed results
The MHRA operates a FakeMeds campaign and provides resources at www.fakemeds.info to help patients identify counterfeit products. If you encounter a suspicious website or seller, report it via the MHRA FakeMeds reporting tool or contact the MHRA directly.
Risks of Buying Sildenafil from Unregulated Sources
Purchasing sildenafil from unregulated sources—including unlicensed websites, social media sellers, or overseas suppliers—poses serious health risks and legal consequences. Research by the MHRA has consistently found that a significant proportion of medicines purchased from illegal online sources are counterfeit, contaminated, or contain incorrect active ingredients.
Health risks associated with unregulated sildenafil include:
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Incorrect dosage – Counterfeit tablets may contain too much or too little active ingredient, leading to ineffectiveness or dangerous side effects including severe low blood pressure, priapism (prolonged painful erection), or cardiovascular events.
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Contaminated products – Illegal manufacturers operate without quality controls, and products may be contaminated with harmful substances.
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Dangerous drug interactions – Without proper medical assessment, patients may unknowingly take sildenafil alongside contraindicated medicines, particularly nitrates used for angina or riociguat, which can cause life-threatening drops in blood pressure.
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Delayed diagnosis – Erectile dysfunction can be an early warning sign of serious conditions including cardiovascular disease, diabetes, or hormonal disorders. Bypassing medical consultation means underlying health problems remain undiagnosed and untreated.
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Allergic reactions – Unregulated products may contain undeclared ingredients that trigger allergic responses.
Additional consequences include:
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Legal implications – Importing prescription-only medicines without a valid prescription is illegal in the UK and may result in prosecution or seizure of goods by customs authorities.
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Financial loss – Counterfeit products are ineffective, and there is no recourse for refunds or complaints when dealing with illegal operators.
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Identity theft – Illegitimate websites may harvest personal and financial information for fraudulent purposes.
If you have inadvertently purchased sildenafil from an unregulated source:
Do not take the medicine. Report the website or seller via the MHRA FakeMeds reporting tool at www.fakemeds.info or contact the MHRA directly. Consult your GP or pharmacist for advice on obtaining sildenafil safely and legally, and discuss any concerns about erectile dysfunction or other health issues that prompted the purchase.
Seek urgent medical help if you experience:
-
An erection lasting more than four hours (priapism)
-
Chest pain, severe dizziness, or fainting
-
Sudden loss of vision or hearing
-
Signs of a severe allergic reaction (difficulty breathing, swelling of the face or throat)
If you experience any side effects from sildenafil, whether obtained legally or otherwise, you can report them via the MHRA Yellow Card scheme at https://yellowcard.mhra.gov.uk. This helps the MHRA monitor the safety of medicines.
Frequently Asked Questions
Can I buy sildenafil over the counter without seeing a doctor?
Viagra Connect 50 mg can be purchased from a pharmacist without a prescription following a consultation to assess suitability and exclude contraindications. All other sildenafil products require a valid prescription from a registered healthcare professional such as a GP or appropriately qualified prescriber.
How much does sildenafil cost privately compared to the NHS?
NHS prescriptions cost £9.90 per item in England (free in Scotland, Wales, and Northern Ireland), but are only available for erectile dysfunction caused by specific conditions such as diabetes or spinal injury. Private sildenafil typically costs £15–£40 per month's supply depending on the provider, dosage, and whether branded or generic versions are chosen.
Where can I purchase sildenafil online safely in the UK?
Sildenafil can be purchased safely from GPhC-registered online pharmacies that require a medical consultation with a UK-registered prescriber before issuing a prescription. In England, these services must also be registered with the Care Quality Commission (CQC); equivalent regulators apply in Scotland, Wales, and Northern Ireland.
What is the difference between Viagra and generic sildenafil?
Viagra is the original branded version of sildenafil manufactured by Pfizer, whilst generic sildenafil contains the same active ingredient and works identically but is produced by other manufacturers. Both require a prescription (except Viagra Connect 50 mg), and generic versions are typically less expensive whilst meeting the same regulatory standards for safety and efficacy.
How do I check if an online pharmacy selling sildenafil is legitimate?
Verify the pharmacy is registered with the General Pharmaceutical Council by checking www.pharmacyregulation.org and look for the GPhC internet pharmacy logo on their website. Legitimate services require comprehensive medical questionnaires, display a UK address and contact details, and in England must be registered with the Care Quality Commission for remote prescribing services.
What should I do if I accidentally bought fake sildenafil online?
Do not take the medicine and report the website or seller via the MHRA FakeMeds reporting tool at www.fakemeds.info. Consult your GP or pharmacist for advice on obtaining sildenafil safely, and seek urgent medical help if you have already taken the product and experience chest pain, prolonged erection, sudden vision loss, or signs of allergic reaction.
The health-related content published on this site is based on credible scientific sources and is periodically reviewed to ensure accuracy and relevance. Although we aim to reflect the most current medical knowledge, the material is meant for general education and awareness only.
The information on this site is not a substitute for professional medical advice. For any health concerns, please speak with a qualified medical professional. By using this information, you acknowledge responsibility for any decisions made and understand we are not liable for any consequences that may result.
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