The U.S. Food and Drug Administration issued twin warning letters to Bayer for its combination supplement/pharmaceutical products. The agency said that drug behemoth Bayer Healthcare's Women's Low Dose Aspirin plus Calcium and its Aspirin with Heart Advantage products are on the market illegally because they did not undergo the necessary procedures for new drugs.

The Bayer Women's product is a combination of aspirin with calcium carbonate and is labeled to "fight" osteoporosis. Heart Advantage contains the plant extract phytosterois, which the label says is a "proven cholesterol-lowering supplement."

"The FDA considers these products new drugs and thus they must undergo the FDA's drug approval process. The FDA will take enforcement action against manufacturers found to be violating the law or attempting to circumvent the drug approval process," said Mike Chappell, an FDA associate commissioner, in a news release.

In its letter, the FDA warned the company that treatments for diseases such as osteoporosis and heart disease must be reviewed by government scientists and cannot be sold over the counter.

"When you add physterols [to aspirin] you no longer have a combination product, you are making a new drug under the law and FDA is making its decision based on this," said Marc Ullman, a partner with New York City-based Ullman, Shapiro and Ullman.

But, Ullman said, if it were permissible by law, the combination product would be a good thing for supplements makers. Although it's not hugely likely, Bayer's response to the FDA's warnings could be to try and change the law. "That would be fantastic for the supplements industry," Ullman said.