A Food and Drug Administration panel has dealt a surprising setback to a highly-anticipated anti-obesity pill.

Health experts said the drug can help people lose weight, but they warned that the drug's side effects outweigh those benefits.

The side effects included memory lapses, suicidal thoughts, heart palpitations and birth defects.

"Some of these side effects are serious and could be life-threatening and must be weighed against a relatively modest weight loss," said the panel's chair, Kenneth Burman of the Washington Hospital Center.

The decision was a major blow to Vivus Inc., a Mountainview, Calif., drugmaker, which was trying to race to the market the first new U.S. prescription weight loss drug in over a decade.

The company said in a statement it was disappointed by the panel's vote and would continue working with the FDA. The agency is scheduled to make a decision on the drug before Oct. 28.

The FDA will consider the panel's ruling and is scheduled to announce its own decision on the drug before Oct. 28.