Erectile dysfunction treatment

Sildenafil and Viagra are essentially the same medication — Viagra is the branded version, while Sildenafil is the generic equivalent containing the same active ingredient. Both work for approximately 4–6 hours and are taken as needed before sexual activity. Tadalafil (brand name Cialis) works in the same way but lasts significantly longer — up to 36 hours — making it a popular choice for those who prefer more spontaneity. Tadalafil can also be taken as a low daily dose. A clinician will help you decide which is best suited to your lifestyle and needs.

No. Sildenafil, Viagra, and Tadalafil are not automatic stimulants — they work by increasing blood flow to the penis, but sexual arousal is still required for them to be effective. The medication simply makes it easier to achieve and maintain an erection when you are sexually stimulated. If you take the tablet and feel no effect, this is often because sufficient arousal was not present, or the dose may need reviewing.

Yes — this is an important safety consideration. Sildenafil, Viagra, and Tadalafil must not be taken with nitrate-based medications (commonly prescribed for chest pain or heart conditions, such as GTN spray or isosorbide), as the combination can cause a dangerous and potentially life-threatening drop in blood pressure. You should also disclose any alpha-blockers, blood pressure medications, or other treatments during your consultation. Always provide a full and accurate medication history before being prescribed.

Common side effects include headache, flushing, indigestion, nasal congestion, and dizziness. These are usually mild and short-lived. Tadalafil can additionally cause back pain or muscle aches in some people. If you experience chest pain, sudden changes in vision or hearing, or an erection lasting longer than 4 hours (priapism), stop taking the medication and seek urgent medical attention via NHS 111 or 999 immediately, as these require prompt treatment.

Sildenafil and Viagra are typically taken 30–60 minutes before sexual activity, though they can take up to an hour to reach full effect — especially if taken with a heavy or high-fat meal, which can slow absorption. Tadalafil as an on-demand dose is usually taken at least 30 minutes beforehand and remains effective for up to 36 hours, so timing is more flexible. If you are taking Tadalafil as a daily low dose, timing relative to sexual activity is not a concern.

Yes, provided you use a regulated UK pharmacy and complete a proper clinical consultation. All prescriptions issued through our service are reviewed by qualified clinicians and dispensed by a GPhC-registered pharmacy. We strongly advise against purchasing ED medication from unregulated websites, as counterfeit products are common and can be dangerous. Look for the EU common logo on any online pharmacy you use, which confirms it is legally registered to sell medicines in the UK.