The Food and Drug Administration, on the heels of last month's ban on ephedrine alkaloids, has begun gathering information on substances used as alternatives to ephedra in certain weight-loss products. The agency has announced it is also compiling data on three other supplements to determine whether they should take action to curb the sales of products containing those items.
"We've started the clock ticking. Maybe it will result in an ephedra-like decision for some of these (supplements), maybe not, said acting FDA Commissioner Lester Crawford, in a speech delivered to the American Society for Pharmacology and Experimental Therapeutics in Washington, D.C.
Shortly after the FDA announced it was imposing a ban on ephedra-containing supplements in December 2003, several supplement manufacturers began using other products similar to ephedra in their formulas and preparations. One of the most commonly used substitutes is bitter orange (citrus aurantium), which contains substances that produce an ephedra-like stimulation and have been shown to increase blood pressure. Crawford said that it was "too soon to say" whether bitter orange should or would be removed from the market.
Also on the FDA's short list are kava, a dried root which is often used as a relaxant and has been linked to kidney damage; usnic acid, a chemical produced by lichen which is used in some weight control supplements; and pyrrolizidine alkaloids, a type of compound commonly found in plants.
While there are some similarities between ephedra and the products listed above, Michael McGuffin, president of the American Herbal Products Association, said that concerns about the ephedra substitutes "are being overblown."
Meanwhile, the Council for Responsible Nutrition, a supplement industry group, said that it supports the FDA's efforts to ensure safety. Council President Annette Dickinson added that many companies have already placed warning labels on some products, including those that contain kava.
In March, the FDA recommended that the National Institutes of Health make studying bitter orange, kava, usnic acid and pyrrolizidine alkaloids a priority. Paul Coates, head of the NIH's Office of Dietary Supplements, said the institute's ephedra studies had created certain steps to evaluate similar products, but would not say if any studies were being planned at this time.