A Chinese supplement actually contains glyburide. This medication can lead to hypoglycemic episodes if not properly monitored:

A dietary supplement available in the United States contains the oral hypoglycemic drug glyburide and could cause life-threatening effects in some people, according to a nationwide alert issued by the Food and Drug Administration last month.

In a statement, the agency warned consumers not to take "Liqiang 4 Dietary Supplement Capsules," because they contain glyburide, the prescription drug approved by the FDA as an adjunct to diet for lowering blood glucose in type 2 diabetics.

The statement urges consumers who have been using the supplement to stop taking it immediately and to seek medical attention, "especially if they are currently being treated with diabetes drugs or if they have symptoms of fatigue, excessive hunger, profuse sweating, or numbness of the extremities."

Liqiang 4 has been sold as part of a shrink-wrapped two-bottle set, according to the FDA statement. One bottle contains 90 capsules and is labeled "Liqiang 4 Dietary Supplement Capsules," and the second bottle is promoted as a bonus pack. Liqiang 4 is manufactured in China, and is available in the United States in herbal stores and by mail order from Bugle International, a Northridge, Calif.-based company. It is advertised in Chinese-language publications, where it is promoted as helping to control diabetes and is described as containing only natural ingredients.

(Mechcatie, "FDA Warns About Supplement That Contains Diabetes Drug", Internal Medicine News, Aug.1)