Few things seem to appeal to drug companies more than the opportunity to sell you a nonprescription pain reliever. Eager to share in this lucrative market, they offer an oriental bazaar of choices.

You may find more than 100 different analgesic products competing for space on the shelves at your local drugstore or supermarket. There are “original” formulas, “new” formulas, and “advanced” formulas. There are tablets, capsules, “caplets,” liquids, and gum. They come in “regular” strength, “extra” strength, and, presumably for those in real agony, “maximum” strength. And the price of the products may vary dramatically, by tenfold or more.

All this apparent variety ends, though, when you examine the ingredients. Inside each package, there is usually only one of three common analgesics: aspirin, acetaminophen, or ibuprofen.

The U.S. Food and Drug Administration (FDA) considers all three effective for the same minor aches and pains. Each can reduce fever and relieve headache, muscle aches, menstrual pain, toothache, and similar discomfort—although they differ somewhat in their effectiveness against certain of these symptoms. For the vast majority of people, occasional use of any of the three analgesics is quite safe. However, each of them can cause unpleasant or serious side effects in certain individuals.