Sildenafil vs Tadalafil vs Vardenafil: Comparing the Three Main ED Tablets

Sildenafil, tadalafil and vardenafil are the three best-known oral treatments for erectile dysfunction (ED). They all belong to the same drug family, the phosphodiesterase type 5 (PDE5) inhibitors, yet they differ enough in how quickly they act and how long they last to make the choice worth thinking through with a healthcare professional.

How all three work

PDE5 inhibitors do not create an erection on their own. They relax the smooth muscle in the blood vessels of the penis so that, when you are sexually aroused, more blood can flow in. Without arousal, very little happens. This is the single most important thing to understand about every medicine in this group.

You can read more about the underlying condition in our overview of erectile dysfunction explained.

The headline differences

• Sildenafil typically starts working within roughly half an hour to an hour and is usually effective for around four to six hours. It is the original and most familiar option. See our Sildenafil guide for more detail.
• Tadalafil has a much longer window of activity, often lasting well over a day, which is why it is sometimes nicknamed the "weekend" tablet. It can be taken on demand or, in some cases, as a low daily dose. See our Tadalafil guide.
• Vardenafil behaves broadly like sildenafil in timing, with an onset of around half an hour to an hour and a similar duration, but some people find it suits them better individually.

Food and timing

Sildenafil and vardenafil can be slowed down by a large or fatty meal, so they are often taken on a relatively empty stomach. Tadalafil is generally less affected by food. None of these tablets should be taken more than once in any 24-hour period unless a doctor has specifically advised a daily regimen.

Choosing between them

There is no single "best" tablet that suits everyone. The right choice depends on:

• How spontaneous you want sex to be — a longer-acting option removes some of the clock-watching.
• How you respond to a given medicine and what side effects you notice.
• Other medicines you take and your overall health.

Common side effects across the group include headache, facial flushing, a blocked or runny nose, indigestion and, less often, changes in vision. These are usually mild and short-lived, but you should always read the patient information leaflet for the specific product you are given.

For a deeper two-way comparison, see Tadalafil vs Sildenafil.

Important safety points for all three

• Never combine any PDE5 inhibitor with nitrate medicines (used for chest pain/angina) or with recreational "poppers" (amyl/butyl nitrites). The combination can cause a sudden, dangerous drop in blood pressure.
• Tell your doctor if you take alpha-blockers, certain blood-pressure medicines or treatments for HIV, as doses may need adjusting.
• An erection lasting more than four hours (priapism) is a medical emergency — seek urgent help.
• Stop and get medical advice if you experience chest pain, fainting or sudden vision or hearing changes.

The bottom line

Sildenafil, tadalafil and vardenafil are closely related and broadly comparable in effectiveness. The practical differences come down to speed of onset, duration and personal tolerance. A doctor or pharmacist can help match the profile to your lifestyle and health. You can browse the full erectile dysfunction range to see the options.

General information only — not medical advice. Always read the patient information leaflet and consult a doctor or pharmacist before starting any medication.