BOSTON (CBS) – U.S. law requires the testing of new drugs before they hit the market to make sure that the benefits outweigh the risks. But according to a new study in JAMA, changes in those laws mean drugs are getting less rigorous review before they get approved.

The FDA has to perform a delicate balance between the thorough testing and timely approval of drugs, and according to researchers at Harvard University and Brigham and Women’s Hospital, testing standards have been loosened, which means more drugs are being approved with fewer studies and less available evidence.

They say that could lead to less confidence in the FDA’s stamp of approval and some drugs may get accelerated approval when it turns out existing or cheaper alternatives are just as good.