Four erectile dysfunction tablets compared
Nearly all tablet treatment for erectile dysfunction uses one of four medicines: sildenafil, tadalafil, vardenafil or avanafil. They share a mechanism and a set of serious warnings. The practical differences lie in how quickly each takes effect, how long it lasts, and a few other uses and forms.
One mechanism, four medicines
Each is a PDE5 inhibitor. Sexual arousal releases nitric oxide in the penis, which raises a messenger called cGMP. cGMP relaxes the blood vessels so that blood can flow in. The enzyme PDE5 clears cGMP away, and these medicines block PDE5, so the signal continues for longer. None of them produces an erection without sexual stimulation.
Side by side
| Medicine | Example product | Time to effect | Duration of effect |
|---|---|---|---|
| Sildenafil | Viagra | Begins within 30–60 minutes | Remains active for 4–6 hours |
| Vardenafil | Levitra | Begins within 25–60 minutes | Remains active for 4–5 hours |
| Avanafil | Stendra | Begins within 15–30 minutes | Remains active for 4–6 hours |
| Tadalafil | Cialis | Begins within 30–60 minutes | Remains active for 24–36 hours |
Timings vary between people.
Warnings that apply to all four
- No nitrates. Every one of the four labels contraindicates nitrate medicines, among them glyceryl trinitrate for angina and amyl nitrite “poppers”. Combining them can lower blood pressure to a dangerous level.
- More than four hours. An erection that continues for longer than this is an emergency and needs urgent medical help. Delay can cause permanent damage to the penis.
- Blood pressure medicines. Alpha-blockers and other drugs that reduce blood pressure may deepen the fall.
- The heart. Sex puts strain on the heart. Anyone with heart disease should ask a doctor whether sexual activity is safe.
Where they differ
Tadalafil lasts much longer than the others. With a half-life of 17.5 hours, one dose still exerts an effect a day and a half later. It is also the only one of the group used for an enlarged prostate, and a low daily version, Cialis Daily, suits men who would rather not time a tablet around sex.
Avanafil acts soonest. Taken without food, it reaches peak levels 30 to 45 minutes after the dose, and its half-life is roughly 5 hours.
Sildenafil and vardenafil fall between the two. A heavy meal may slow them down. Sildenafil, at a lower dose, also treats pulmonary arterial hypertension.
Udenafil is a fifth PDE5 inhibitor, sold as Zudena. It was developed in South Korea and is less widely known.
Headache, flushing, indigestion and nasal congestion are common to the group. Tadalafil may also bring back pain and muscle aches.
Choosing between them
No single medicine is best; the choice turns on how you expect to use it. A shorter-acting tablet fits a planned occasion, while tadalafil leaves a longer window. If one does not suit you, another may.
Erectile dysfunction can be an early sign of heart disease or diabetes, so a doctor can look for the underlying cause and check whether any of your other medicines rule out one of the four.
Forms beyond the standard tablet exist: oral jelly, chewable tablets, and films that are placed on the tongue. Generic ED medicines explained covers them.
Orders reach Malaysia from pharmacy partners in India in discreet packaging. Express Tracked Courier takes up to 1 week; Standard Airmail takes up to 3 weeks.