Sildenafil is a medicine used to treat erectile dysfunction (ED). It works by relaxing blood vessels in the penis, which increases blood flow and helps achieve and maintain an erection during sexual stimulation. It is the active ingredient in Viagra, one of the most widely prescribed ED treatments.

Sildenafil is effective for around 7 in 10 men with erectile dysfunction. The response depends on the underlying cause of ED and overall health. Clinical studies show improved erections within 30–60 minutes of taking it, with effectiveness lasting for several hours. Lifestyle factors such as smoking, alcohol, and certain medical conditions can affect results.

Sildenafil usually works for 4–6 hours after taking a dose. The effect may vary depending on age, metabolism, food intake, and overall health. It does not cause a constant erection; sexual arousal is still required for it to work.

Take sildenafil with a glass of water, about 30–60 minutes before planned sexual activity. Do not take more than one dose in 24 hours. Avoid heavy meals or high-fat foods, as these can delay the effect. Alcohol can also reduce effectiveness and increase the chance of side effects.

Sildenafil is available in 25mg, 50mg, and 100mg tablets. The recommended starting dose for most men is 50mg, taken when needed. Depending on how you respond, our prescriber may lower it to 25mg or increase it to 100 mg.

Sildenafil is safe and well tolerated by most men. Common side effects include headache, flushing, indigestion, nasal congestion, and dizziness. These effects are usually mild and improve as your body adjusts.

Rare but serious side effects include chest pain, sudden loss of vision, or a prolonged, painful erection lasting over 4 hours (priapism). If any of these occur, seek urgent medical help immediately. Our clinical team is available if you have any concerns.

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There is no difference in the active ingredient. Viagra is the original branded version, while sildenafil is the generic name. Generic sildenafil is medically identical to Viagra and works in the same way. The main difference is cost, as generic versions are usually cheaper.