Seeking a new supplement

People who think ephedra helped them lose weight are looking to new ingredients with names like guarana, bitter orange and green tea extract to replace the soon-to-be-banned dietary supplement.

There's little proof yet that ephedra alternatives actually burn pounds, and scientists warn that some come with health considerations of their own -- including an ephedra mimic that might interact dangerously with medicines the dieter also swallows.

"There are a number of, quote-unquote, 'ephedra substitutes' on the market now where even less is known about potential side effects," Food and Drug Administration Commissioner Mark McClellan cautioned in an interview last week.

The FDA will pull ephedra off the market soon and wants consumers to stop immediately using the herbal stimulant, which is linked to 155 deaths and dozens more heart attacks and strokes.

Many consumers are ignoring that advice. There has been a run on remaining ephedra supplements since FDA's warning two weeks ago, even though studies show ephedra helps people lose only a few pounds more than dieting alone.

Still, as January ushers in postholiday diets, Americans are turning to the burgeoning ephedra-free market, too. Topping the lists of new ingredients are caffeine-containing supplements, some that deliver the buzz of at least three cups of coffee in one dose. Not all mention caffeine on the label; consumers may have to learn herbal aliases such as guarana and green tea to ensure they don't get caffeine jitters by taking multiple supplements.

The ingredient drawing the most attention is bitter orange, which McClellan says the FDA is monitoring closely because it contains synephrine, a stimulant chemically similar to ephedra.

Also called citrus aurantium, the peel of this very sour "Seville orange" is found in some foods like orange marmalade.

"It's not as potent as ephedra unless you take it in much higher doses," says Mark Blumenthal of the American Botanical Council.

But some scientists note that synephrine can increase blood pressure and constrict blood vessels, as ephedra does, and question whether using it with caffeine could worsen those effects the way taking ephedra with caffeine does.

"There's not really a reason to think citrus aurantium will be safer," says Dr. Adriane Fugh-Berman of Georgetown University, an expert on herbal supplements.

More worrisome, she says, is that bitter orange could interact dangerously with prescription or over-the-counter drugs.

Why? It's related to a longtime warning against taking medications with grapefruit juice. Grapefruit contains a natural chemical that inhibits one of the body's drug-metabolism routes so that some medicines build up to dangerous levels, and bitter orange contains even more of that drug-boosting substance, says Fugh-Berman.

Studies to date show bitter orange inhibits metabolism of at least two drugs, the popular over-the-counter cough medicine dextromethorphan and the prescription blood-pressure drug Plendil.

As for shedding pounds, there's no evidence in people yet that it works.

Other ephedra alternatives:

Green tea extract. Green tea typically contains less caffeine per cup than coffee, plus many antioxidant vitamins.

Caffeine itself can be a mild appetite suppressant, and proponents say there may be other substances in green tea that could slightly speed calorie burning. There's no evidence yet that green tea causes weight loss, but Fugh-Berman calls the possibility interesting and says the substance probably is harmless.

Guarana, used in a popular Brazilian soft drink, contains two to three times as much caffeine as coffee, Blumenthal says. Other caffeine-containing supplements are kola and mate.

Garcinia, also called hydroxycitric acid. A Journal of the American Medical Association research review found no good evidence of weight loss.

"Starch-blocking" pills promise to help starchy foods pass through the body with less calorie absorption. Most are made with kidney-bean extracts not thought to be harmful. Supplement giant Metabolife International cites a small study that found users dropped slightly more weight than regular dieters, but the research has not been published.

Old-fashioned fiber works on the same principle and can fill people up so they eat less, notes Fugh-Berman. But she says it's impossible to get as much fiber in a pill as from a glass of Metamucil, made with the soluble fiber psyllium.

Bladderwrack, an herb that contains a lot of iodine, which could cause or worsen thyroid disease, notes a recent supplement review by University of Montana pharmacists. Germany, which strictly regulates herbal medicines, lists bladderwrack as unapproved, citing the health risk and lack of evidence that it burns pounds.