New research suggests that more rigorous regulatory oversight is needed in the dietary supplements industry.

A study has shown that many supplements that have been recalled by the U.S. Food and Drug Administration (FDA) are still on sale in the same formulation, containing potentially dangerous prescription drug ingredients.

Researchers tested 27 products bought online, ranging from weight loss supplements to products promising big muscles or enhanced sexual performance. The products had all previously been subject to recall after the FDA raised concerns about what they contained.

Among these products, 18 were found to include ingredients that are not approved for over-the-counter use and 17 still contained the same drug that prompted the recall. Tests revealed the presence of hidden steroids, ingredients similar to Viagra and Prozac and a weight loss drug linked with heart attacks, the Associated Press reported.

Lead author Dr. Pieter Cohen, a Cambridge Health Alliance researcher, claimed that the manufacturers of these supplements were putting profit ahead of consumer health. He said that lax oversight by the FDA was contributing to the problem.

"There should be significant legal and financial consequences for manufacturers who the FDA finds to be continuing to sell these spiked supplements," Dr. Cohen commented.

The solution to the problem may be laws that increase the FDA's enforcement powers, the researchers believe.

The findings of the study have been published in the Journal of the American Medical Association.