Ephedra-free diet pills may carry risks, too

Some of the weight-loss aids that have quickly emerged to replace the now-banned substance ephedra may carry risks of their own, a small study suggests.

Researchers at the University of California, San Francisco found that two ephedra-free diet supplements increased the heart rates of 10 healthy volunteers, and one also raised their blood pressures. These effects are similar to what has been seen with ephedra, an herbal stimulant that was banned in the U.S. last year after reports linked it to heart attacks, strokes and at least 155 deaths.

The supplements, sold as Advantra Z and Xenadrine EFX, both contain extracts of bitter orange, known scientifically as Citrus aurantium. The botanical, which has long been used in traditional Chinese medicine for digestive problems, has emerged as one of the major replacements for ephedra in over-the-counter weight-loss products.

Citrus aurantium contains a compound called synephrine that, like ephedra, stimulates the central nervous system and may boost metabolism.

But there has been little research to show that supplements containing bitter orange extract are either safe or effective, Dr. Christine A. Haller, the lead author of the new study, said in an interview.

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