Yes. Following regulatory approvals, specific sildenafil products (commonly known by their brand name Viagra) are available as Pharmacy medicine (P) in the UK. This means that qualified pharmacists can supply short-term treatment for erectile dysfunction without a doctor’s prescription. Not every sildenafil product, strength or pack size is available without prescription. Higher doses and certain pack formats remain Prescription Only Medicines (POM). Always confirm the legal status of the exact product you wish to buy.
Non-prescription Viagra is intended for men with erectile dysfunction (ED) who have been appropriately assessed by a pharmacist. It is not suitable for every patient or every form of sexual dysfunction. Your pharmacist may ask questions about your health, existing conditions and other medicines to ensure safe supply.
The UK categorises human medicines into three main legal classes: General Sales List (GSL), Pharmacy medicine (P) and Prescription Only Medicine (POM). A Pharmacy medicine can be sold only in a registered pharmacy and must be supplied by or under the supervision of a pharmacist. This ensures professional oversight for products that require more guidance or have safety considerations beyond general-sales items.
Viagra sold as P is provided after a pharmacist’s assessment of suitability, contraindications and specific patient needs. This controls appropriate access while avoiding the need for a doctor’s prescription for many patients seeking relief from erectile dysfunction.
Sildenafil is the active pharmaceutical ingredient in Viagra and its generic equivalents. It belongs to a class of medicines called phosphodiesterase type 5 (PDE5) inhibitors. By inhibiting PDE5, sildenafil enhances the body’s natural erectile response to sexual stimulation.
Viagra was first authorised for prescription use in the UK in 1998. In 2024 it gained a non-prescription classification for certain doses and pack sizes, making it one of the first PDE5 inhibitors available without a prescription in the UK.
Generic sildenafil contains the same active ingredient as Viagra at equivalent strengths. Generic manufacturers must demonstrate bioequivalence to the reference medicine. Inactive ingredients such as fillers, dyes and coatings can differ between brands, affecting tablet appearance but not clinical effectiveness.
Viagra tablets are film-coated to protect the active ingredient, aid swallowing and improve appearance. Some generics may use different coatings or excipients, but they must dissolve appropriately in the digestive tract to release the active drug.
No. Sildenafil does not increase sexual desire. It facilitates erection in response to physical stimulation by improving blood flow to the penis. Sexual arousal must still occur for the drug to work.
Sexual stimulation triggers the release of nitric oxide in penile tissue. This leads to increased levels of cyclic guanosine monophosphate (cGMP), a molecule that relaxes smooth muscle vessels. Relaxation allows more blood to fill the corpus cavernosum, producing an erection.
PDE5 is an enzyme that breaks down cGMP. By limiting the action of cGMP, PDE5 can cause blood vessels to constrict and an erection to subside prematurely.
Sildenafil competitively binds to the PDE5 enzyme, preventing cGMP breakdown. This prolongs the vasodilatory effects of cGMP, thereby supporting an erection during sexual activity.
Onset of action typically occurs within 30–60 minutes after oral administration. Factors such as food intake, particularly high-fat meals, can delay absorption and onset. For best results, take sildenafil on an empty stomach or after a light meal.
Viagra’s effects can persist for up to four to five hours. Duration varies between individuals. The drug does not produce a continuous erection; it facilitates the normal erectile response during that window.
Prices for Viagra and generic sildenafil vary by strength, pack size and retailer. Our online pharmacy offers competitive pricing and special offers for bulk purchases. Check our live price listings or contact Elstree Pharmacy for the latest deals.
Retail pricing can reflect distribution costs, sourcing arrangements, brand premiums and promotional strategies. A lower price does not imply inferior quality. All licensed generics must meet the same regulatory standards as the originator brand.
| Product | Strength | Pack size | Price (GBP) | Status | Note |
|---|---|---|---|---|---|
| Viagra | 50 mg | 4 tablets | £24.99 | P (Pharmacy medicine) | Supply after pharmacist assessment |
| Generic sildenafil | 50 mg | 4 tablets | £19.99 | P (Pharmacy medicine) | Fast delivery UK-wide |
| Generic sildenafil | 100 mg | 4 tablets | £29.99 | POM | Prescription required |
The non-prescription classification currently covers sildenafil 50 mg tablets in packs of up to four. Other strengths (25 mg, 100 mg) and larger pack sizes remain POM.
Viagra and generic sildenafil are supplied as film-coated tablets. Research into alternative formulations—such as orodispersible tablets—continues, but as of this article, oral tablets are the only licensed forms.
Pack size can influence legal classification and recommended duration of self-treatment. Limiting pack size helps ensure pharmacist oversight, encourages short-term use and prompts users to seek further advice if symptoms persist.
Branded Viagra and licensed generics contain the same active ingredient. Patients may notice differences in tablet colour, size or taste, but clinical effect is equivalent when products are authorised as bioequivalent.
Erectile dysfunction is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It can have physical, psychological or mixed causes.
ED affects men of all ages but is more prevalent in older men. Studies suggest up to 50% of men aged 40–70 may experience some degree of erectile difficulty.
Physical causes include cardiovascular disease, diabetes, obesity, hormonal imbalances, neurological disorders and certain medications. Psychological factors can include stress, anxiety, depression and relationship issues.
If erectile dysfunction is new, persistent or accompanied by other health concerns (e.g., chest pain, breathlessness), see your GP. A comprehensive assessment can identify underlying conditions and guide appropriate treatment.
GSL medicines can be sold in non-pharmacy outlets under defined conditions. Sildenafil is not available as GSL due to safety considerations.
Pharmacy medicines (P) require pharmacist supervision but not a prescription. They provide a balance between access and professional oversight for medicines that need advice or screening.
Prescription Only Medicines (POM) must be supplied with a valid prescription from an authorised prescriber. Higher strength sildenafil and larger packs remain POM.
Regulatory classification considers safety profile, risk of misuse, need for professional assessment and condition seriousness. ED medication requires some screening, hence pharmacy-only supply for certain doses.
Choice of therapy depends on patient preference, comorbidities, contraindications and previous response to treatments. Pharmacist or GP input can help select the most appropriate option.
Sildenafil: onset 30–60 mins, duration 4–5 hrs Tadalafil: onset 30–45 mins, duration up to 36 hrs Vardenafil: onset 30–60 mins, duration ~5 hrs Avanafil: onset ~15–30 mins, duration ~6 hrs
Sildenafil and vardenafil can be delayed by high-fat meals. Tadalafil and avanafil are less affected by food.
| Feature | Sildenafil | Tadalafil | Vardenafil | Avanafil |
| Drug class | PDE5 inhibitor | PDE5 inhibitor | PDE5 inhibitor | PDE5 inhibitor |
| Prescription uses | ED | ED, BPH | ED | ED |
| OTC in UK | Yes (50 mg only) | No | No | No |
No. Efficacy and tolerability vary between individuals. Personal preference, cost and schedule of sexual activity influence choice.
Excessive alcohol can impair erection. Moderate alcohol may not preclude sildenafil use but discuss drinking habits with your pharmacist.
Smoking is a risk factor for vascular disease and erectile dysfunction. Quitting can improve overall health and sexual performance.
Discussing expectations, anxieties and preferences with your partner supports treatment success and mutual satisfaction.
If anxiety or stress contributes significantly to ED, consider counselling or sex therapy alongside pharmacological treatment.
Headache, flushing, dyspepsia, nasal congestion, dizziness. Usually mild and transient.
Visual disturbances (blue vision), tinnitus, palpitations, myalgia.
Priapism (prolonged erection >4 hrs), sudden vision or hearing loss. Seek immediate medical attention.
| Area | Examples |
| Cardiovascular | Palpitations, hypotension |
| Neurological | Visual changes, headache |
| Gastrointestinal | Indigestion, nausea |
| Long-term | No major issues at recommended dosing |
Product leaflets list full side effect profiles, frequency categories and advice on managing adverse reactions.
Long-term sildenafil at prescribed doses is generally safe. Regular review by a healthcare professional is advisable if use continues beyond six months.
Sildenafil does not cause physiological dependence. There is no evidence of tachyphylaxis (rapid loss of effect) with continued use.
Occasional blood pressure checks and review of cardiovascular status may be warranted for men with underlying heart disease.
If ED worsens, if side effects become bothersome or if new symptoms arise (e.g., chest pain), discontinue use and seek medical advice.
Sildenafil is metabolised by CYP3A4. Avoid concomitant use with potent inhibitors (e.g., ketoconazole) or inducers (e.g., rifampicin). Caution with alpha-blockers due to risk of hypotension.
Grapefruit juice can increase sildenafil levels; avoid high volumes. St John’s Wort may reduce effectiveness by inducing metabolism.
Sildenafil is not indicated for women. Its safety in pregnancy and breastfeeding has not been established.
If allergic reactions (rash, swelling), priapism, sudden visual/hearing loss or severe hypotension occur, seek urgent medical care.
Both contain sildenafil citrate as the active ingredient. Generic versions match the reference product in quality and efficacy, though they may differ in appearance and excipients.
Different manufacturers can have varying patient information leaflets depending on product licence, pack size and authorised indications.
Check packaging for MHRA approval marks, batch number and expiry date. Purchase only from regulated pharmacies like Elstree Pharmacy.
Sources include the MHRA website, electronic Medicines Compendium (eMC) and professional pharmacists or GPs.
No. This article is for general guidance from Elstree Pharmacy (The Corner Shop B, High Street, Elstree, WD6 3BY). For personalised advice, speak directly with our pharmacy team or your GP.
