Once again, a potentially dangerous drug has been found in dietary supplements.

More than 30 weight-loss products have been recalled by the U.S. Food and Drug Administration. Sold under the names, "Slim Waist Formula," "21 Double SLIM" "24hours Diet" and others, these products were found to illegally contain the drug sibutramine, the active ingredient in the prescription drug Meridia.

Sibutramine is not listed on the label for these products and according to the FDA, the drug can substantially increase blood pressure in some patients, and put those with have a history of coronary artery disease, congestive heart failure, arrhythmias, or stroke at risk.

Last month, we reported that the FDA issued warnings on 72 weight-loss drugs that illegally included substances like Fluoxetine, an prescription antidepressant, Furosemide, a potent prescription diuretic, Phenolphthalein, a solution used in chemical experiments, and a suspected cancer-causing agent that is not approved for marketing in the United States and others.

If you are taking any of the 34 supplements listed, stop immediately and see a healthcare professional.

—Lisa Gill, editor, Prescription Drugs

Read our previous coverage on the diet pills, and see our list of supplement ingredients you should avoid.