Sildenafil and tadalafil are the two most widely prescribed treatments for erectile dysfunction. Both help most men who try them, and both are now available as affordable generics. The question that matters is often not which read more one is "better", but which one suits the way you live.
Sildenafil is normally taken about an hour before sex and lasts around four to five hours. A large meal can delay the effect. Tadalafil, on the other hand, can work for up to 36 hours, and food makes little difference. Many men also take a low daily dose of tadalafil so they never need to time a tablet.
To compare the two in more detail, see this plain-English guide covers doses, timing and safety.
Safety first: never take either medicine with nitrate heart medicines or with "poppers". Tell your doctor about any alpha-blockers. Common side effects are headache, flushing, a blocked nose and indigestion. Seek medical help straight away for an erection lasting more than four hours or sudden changes in vision.
Strength matters too. The licensed doses are 25, 50 or 100 mg for sildenafil and 2.5 to 20 mg for tadalafil. Higher-strength tablets do not bring better results, but they do raise the risk of side effects. Only take the dose your prescriber has set.
When you buy medicine online, check the strength on the pack and read the patient leaflet. A valid prescription is required for every order of a prescription medicine. There is more detail in this tadalafil and sildenafil guide.
This is general information, not medical advice. Always check with your doctor before starting a new medicine.