"There is an honest justification for having different drugs on the market to treat the same condition because different people respond differently to different drugs. That's a fact -- it's a clinical truth," Saper said.
In most cases, competing brands contain the exact same dosage of active ingredient. Advil, for example, contains 200 milligrams of ibuprofen, as does competing brand Motrin IB. Extra Strength Tylenol contains 500 milligrams of acetaminophen, as does Extra Strength Anacin, which also includes a small amount of caffeine.
The differences in the ever-expanding number of delivery modes are also mostly cosmetic. Tylenol is the leader in creating options, offering its Extra Strength Tylenol in six different pill forms as well as a liquid. Advil and Aleve are packaged in three pill forms, and Bayer offers a safety-coated aspirin pill.
The fancy coatings, with catchy names like gelcaps, cool caplets and liquid gels, are little more than window dressing, experts say. And drugmakers concede that there is little to differentiate the medicine in the pills.
"For everything besides liquid gels it's consumer preference. The liquid gels tend to work faster, and some pills are a little bigger than others," said Fran Sullivan of Wyeth Consumer Healthcare, which makes Advil. "They choose which pill form they like the best."
But even claims of faster-releasing medicine in liquids or pills in "liquid gel" form are not without controversy.
"There's no science that demonstrates that any form of pill or liquid delivers medicine quicker. That's consumer preference -- some people just prefer a tablet or a caplet or a liquid," said Kathy Fallon, spokeswoman for McNeil Consumer & Specialty Pharmaceuticals, the maker of Tylenol.
In 2000, the FDA permitted drug companies to label pain products as "migraine relievers." Migraine products carry different instructions and labels, but that labeling does not guarantee any difference in actual pain medicine. Advil Migraine and Advil Tablets both contain 200 milligrams of ibuprofen. Excedrin Migraine contains the same combination of 250 milligrams of acetaminophen and 65 milligrams of caffeine as Excedrin Extra Strength.
"If you go to the store and buy a 'migraine' medicine, you might assume -- wrongly -- that it's stronger medicine," Saper said. "It's mostly a marketing gimmick because it's going to be exactly the same drugs."
Certain products also claim to offer relief from "body pain" or "sinus pain," but a glance at the active ingredients shows that they rarely differ much from the standard doses.
For consumers looking for the most appropriate pain relief, the only true way to differentiate between the options is to ask the old standby question: Do you need regular strength or extra strength? Ibuprofen and naproxen products come only in the 200 milligram doses, but regular strength versions of Anacin, Tylenol and Excedrin include a smaller amount of the active ingredient than their extra-strength companion products.
But even that might not be worth worrying about. Experts say taking any of the FDA-approved, over-the-counter products in the suggested dosages is safe for short periods of time, regardless of the strength level.
"You don't want to take more of a drug than you have to, and you don't want to overmedicate. But if you follow the directions, they should be safe," Saper said.