In a recent study, researchers analyzed 17 brands of weight loss or sports products labeled as supplements that listed deterenol (or a synonym) as an ingredient.

All contained either deterenol or other unapproved stimulants (or both). Some, like 1,3-DMAA, may cause heart attacks, warns the FDA. All are illegal.

What to do

Beware of supplements marketed as weight, fat-burning, or pre-workout aids. Some may contain unsafe stimulants.