– Most men feel an effect in 30–60 minutes
– It can work for up to about 4 hours

This doesn’t mean you will have an erection for 4 hours – it means that within this window, it is easier to get and maintain an erection when sexually stimulated.

If you take it with a large or fatty meal, it may:

– Take longer to start working
– Feel less effective

It’s quite common for sildenafil to not feel perfect on the first try. Consider the following:

– Try it on at least a few separate occasions
– Make sure you are allowing enough time (around 1 hour)
– Avoid heavy meals and limit alcohol
– Make sure there is adequate sexual stimulation (it will not work without it)

If, after several attempts:

– You still get no improvement, or
– You get some effect but it is not strong enough

speak to your prescriber. They may:

– Adjust your dose (if safe)
– Check for other causes (e.g. low testosterone, cardiovascular issues)
– Suggest a different ED medicine or treatment approach

Sildenafil does not cure ED permanently. It:

– Treats the symptom by improving erections while it’s in your system
– Does not fix underlying long-term causes like diabetes, smoking or psychological factors

However, addressing lifestyle issues (e.g. exercise, weight, alcohol intake, smoking cessation) and treating underlying conditions can improve ED over time.

Sildenafil has a blood-pressure-lowering effect and puts some extra strain on the heart during sexual activity, so:

– It is generally safe for most men with stable heart disease, but
– It is not suitable if you have been told not to have sex or if you use nitrates/nicorandil

Your prescriber will screen for:

– Recent heart attack or stroke
– Unstable angina or serious arrhythmias
– Very low or uncontrolled high blood pressure

If you have any new chest pains, breathlessness, or symptoms on exertion, see a doctor urgently before using ED medicines.

Not everyone gets side effects, but common ones include:

– Headache
– Flushing (warm/red face)
– Indigestion or heartburn
– Blocked or runny nose
– Dizziness or light-headedness
– Visual changes (e.g. blue tinge, blurred vision, increased sensitivity to light)

These are usually mild and short-lived. If they are troublesome, tell your prescriber – a dose adjustment or alternative treatment may help.

More serious side effects – seek urgent medical help if:

– You develop chest pain during or after sex
– You have an erection that lasts more than 4 hours (priapism) – this is a medical emergency and can cause permanent damage if not treated
– You suddenly lose vision in one or both eyes
– You experience sudden hearing loss or ringing in the ears with dizziness
– You feel faint, collapse, or have severe chest or jaw pain

Stop taking sildenafil and seek immediate medical help in these situations.

Extra caution is needed if you:

– Take alpha-blockers for blood pressure or prostate problem- Have kidney or liver impairment
– Have anatomical issues with the penis or conditions that predispose to priapism
– Have previously experienced serious eye issues such as NAION

Always give full details of your medical history and medications in your questionnaire.

– Moderate alcohol (e.g. 1–2 units) is unlikely to cause a serious interaction, but:
– Too much alcohol can make it much harder to get an erection, and may worsen side effects like dizziness and low blood pressure

For best results, keep alcohol low or avoid it when planning to use sildenafil.

No. You should not take sildenafil at the same time as:

– Other PDE5 inhibitors (e.g. tadalafil, vardenafil, avanafil)
– Vacuum devices or injections without medical guidance

Combining PDE5 inhibitors increases the risk of low blood pressure and side effects without improving benefit.

If sildenafil is not working for you, your prescriber may switch you to a different ED treatment, but not combine them.

Sildenafil for ED is taken when needed, not on a strict schedule:

– If you forget to take it before sex, you can take it when you remember (allowing time for it to work)
– Do not take more than one dose in 24 hours

In the UK, sildenafil for ED can be:

– Available on the NHS for some men under specific criteria (e.g. certain medical conditions) via their GP
– Supplied on a private prescription via online or in-person clinics for those outside NHS criteria

This online service uses a private prescription model, following an assessment by a prescriber.

Call 999 or go to A&E if you:

– Have chest pain, tightness, or pain spreading to your arm, jaw or back during or after sex
– Have an erection lasting more than 4 hours
– Suddenly lose vision or hearing
– Collapse, or feel very faint or unwell after taking tadalafil

Call NHS 111 or speak to a doctor promptly if you:

– Have concerning side effects that are not settling
– React badly to the medicine but are not sure if it is an emergency