Sildenafil is a well-established and clinically proven treatment for erectile dysfunction (ED). Erectile dysfunction is a common condition that can affect men at any stage of life and is characterised by difficulty achieving or maintaining an erection sufficient for satisfactory sexual activity.

Sildenafil belongs to a group of medicines known as phosphodiesterase type 5 (PDE5) inhibitors. It works by increasing blood flow to the penis during sexual stimulation, allowing an erection to occur naturally. Sildenafil does not cause an erection without sexual arousal and will only be effective when you are sexually stimulated.

How to take Sildenafil

Sildenafil is usually taken as needed, approximately 30 to 60 minutes before sexual activity. The effects can last for up to 4 hours, although this can vary between individuals.

The typical starting dose is 50 mg, which may be adjusted by a prescriber depending on effectiveness and tolerability. Some individuals may be prescribed 25 mg or 100 mg based on clinical need.

Sildenafil should not be taken more than once in a 24-hour period.

It is recommended to take sildenafil on an empty stomach, as a heavy or high-fat meal may delay its onset of action.

Who Sildenafil is suitable for

Sildenafil may be suitable for adult men experiencing erectile dysfunction, following assessment by a qualified prescriber.

At Mr Chemist, all patients are required to complete a secure online consultation. A UK-qualified prescriber will review your medical history, current medications, and suitability before any treatment is issued.

Treatment is only provided where clinically appropriate.

Who should not take Sildenafil

Sildenafil is not suitable for everyone. You should not take sildenafil if you:

• Are taking nitrate medications (e.g. glyceryl trinitrate) or nicorandil

• Have been advised to avoid sexual activity due to cardiovascular risk

• Have severe heart or liver problems

• Have low blood pressure or certain eye conditions such as non-arteritic anterior ischaemic optic neuropathy (NAION)

A prescriber will assess your suitability based on your individual medical history.

Possible side effects

Like all medicines, sildenafil can cause side effects, although not everyone will experience them.

Common side effects include:

• Headache

• Flushing

• Indigestion

• Nasal congestion

• Dizziness

• Visual disturbances (such as a blue tinge to vision)

Less common but important side effects:

• Prolonged or painful erection (priapism)

• Sudden loss of vision or hearing

• Chest pain or severe dizziness

If you experience any serious or persistent side effects, you should seek medical attention immediately.

Drug interactions

Sildenafil can interact with certain medications. It is particularly important to avoid sildenafil if you are taking:

• Nitrates or nitric oxide donors

• Nicorandil

• Certain blood pressure medications

• Some antifungal or antibiotic treatments

• Other treatments for erectile dysfunction

You should always provide full details of your current medications during your consultation so that your prescriber can assess safety.

Important considerations

• Sildenafil does not increase sexual desire

• It does not provide protection against sexually transmitted infections

• Alcohol may reduce effectiveness and increase the risk of side effects

• Lifestyle factors such as smoking, obesity, and underlying health conditions can affect treatment response

Clinical assessment and prescribing

At Mr Chemist, all consultations are reviewed by a qualified UK prescriber. We may access your Summary Care Record (SCR), where available, to support safe prescribing.

If sildenafil is not suitable for you, we will provide appropriate guidance or discuss alternative treatment options.

Your medication will only be dispensed once it has been clinically approved and will be supplied by our UK-registered pharmacy.

Discreet and convenient service

We understand that erectile dysfunction can be a sensitive issue. Our service is designed to be discreet, confidential, and clinically safe, allowing you to access treatment without the need for a face-to-face appointment.