The US Food and Drug Administration (FDA) on Friday warned consumers not to use a brand of weight loss pills that claim to be "100 percent herbal" after lab tests showed they contain a dangerous stimulant.
FDA laboratory tests found that Slimming Beauty Bitter Orange Slimming Capsules contain "excessive amounts of sibutramine," a stimulant which is supposed to be available only on prescription and which could cause high blood pressure, stroke or heart attack in some consumers.
Sibutramine poses risks especially to people with cardiovascular conditions, but also to healthy people who take the amount of sibutramine found in Slimming Beauty capsules.
People who take diet capsules could experience anxiety, nausea, heart palpitations, a racing heart, insomnia, and elevated blood pressure, the FDA warned.
The stimulant, which is not listed on the pills' label, could also interact with other medications and cause serious side effects.
The slimming capsules are sold over the Internet, and sample packets have been distributed at community events, including at the annual Mexican Independence Day parade in Chicago last month, the FDA said.
"The sample packet label is misleading because it indicates that it is a natural vitamin and calcium capsule for use in children as young as two years old," the FDA said in a statement.
The watchdog agency said it has had "several reports of serious side effects from the use of this product including elevated blood pressure, headaches, vomiting and insomnia."