A placebo-controlled study conducted at UCSF reveals two popular weight loss supplements that are promoted as “ephedra-free” and safe for dieters could have harmful effects on some people.
The findings are published in this month’s issue of the American Journal of Medicine.
Both of the weight loss products tested contain Citrus aurantium, or bitter orange extract, a substance that is rapidly replacing ephedra in dietary supplements since its ban by the FDA last year due to concerns about severe health effects of the herbal supplement.
(Although a federal judge lifted the ban, ephedra has gradually been phased out by many supplement manufacturers concerned with potential civil liability for injuries and deaths blamed on the supplement.)
In the first clinical study of the effects of these newly formulated dietary supplements, researchers monitored blood pressure, heart rate, moods, and emotions of 10 healthy adults.
Single doses of both Xenadrine EFX and Advantra Z caused increased heart rate among those tested. Xenadrine EFX also increased blood pressure and alertness. Neither product showed a serious effect on mood.
Researchers found that while Advantra Z contains only bitter orange, one dose of Xenadrine EFX has many other ingredients, including as much caffeine as found in 3 cups of coffee.
They concluded that the increased blood pressure Xenadrine EFX caused did not come from the caffeine alone, but was probably due to the combination of other ingredients of the supplement.
According to Christine Haller, MD, UCSF assistant professor of medicine and lead author of the paper: "These findings indicate that ephedra-free dietary supplements could have some of the same adverse health effects associated with previously available ephedra products, such as Metabolife 356 and Ripped Fuel."
Until longer-term studies of these weight loss supplements are conducted, doctors should alert patients to the potential dangers of ephedra-free dietary supplements and should monitor blood pressure in people who choose to use them.