Watch out for side effects of ED pills

The most common side effects are headaches, upset stomach, nasal congestion, muscle pain, and facial flushing. But most of these are relatively mild and go away after a few hours.

ED drugs can make blood pressure temporarily drop, so never use them if you also take medications that contain nitrates. (Nitrates found in food don't pose a problem.)

You also need to be careful if you take any other drugs that lower blood pressure. For example, alpha blockers — such as tamsulosin (Flomax) and alfuzosin (Uroxatral), which are used to treat symptoms of an enlarged prostate, lower blood pressure in some men. Make sure to take them at least four hours apart from an ED drug.