Some of the biggest names in diet aids now tout that their products are free of ephedra, the supplement linked to heart attacks, high blood pressure and heatstroke.
The granddaddy of weight-loss supplements, Metabolife, recently began offering a version without the herb.
Dexatrim pulled its ephedra products from the market late last year and now offers two different ephedra-free products Dexatrim Natural and Dexatrim Results. Ripped Fuel, BetaLean, Hydroxycut, Phen-Free, Metabolite, Metabolift and General Nutrition Center’s Total Lean also are available without ephedra.
But ephedra is often being replaced by an untested mix of herbs that contain potent stimulants, including one that’s a chemical cousin of ephedra.
“They are basically substituting one drug for another,” said William Gurley, a drug metabolism expert and professor at the University of Arkansas for Medical Sciences. “Yes, they may be ephedra-free, but many still subject consumers to the same adverse effects associated with ephedra.”
The National Institutes of Health’s Office of Dietary Supplements is warning consumers about the products. Dr. Paul Coates, the office’s director, said that far less is known about the risks of the replacement herbs than about ephedra itself.
“The fact that a dietary supplement is ephedra-free is not an indication of its safety,” he said.
Calls made last week to several manufacturers of ephedra-free diet aids were not returned.
Medical experts are particularly concerned about a common ingredient in the products that is derived from an herb called bitter orange or Citrus aurantium. The fruit of the plant, which grows wild in Asia, contains in its peel a chemical called synephrine, long used in nasal sprays that treat cold symptoms. Because it’s a stimulant, it’s also promoted as a way to speed metabolism and lose weight.
Gurley said synephrine and ephedrine, the stimulant found in ephedra, are similar compounds.
Because of this, he said, it could cause many of the same problems as ephedrine. Gurley is unaware of any medical problems linked to bitter orange’s use. The U.S. Food and Drug Administration (FDA) Web site lists no medical problems caused by the herb.
However, Gurley said because the products containing it are new, problems might not be evident for some time.
“With synephrine, we’re where we were six to seven years ago with ephedrine,” he said.
Dr. Christine Haller, an ephedra researcher, said she believes it’s “a matter of time” before medical problems are reported in people using bitter orange weight-loss products.
Little research has been done to determine whether bitter orange is safe or effective in helping people lose weight, she said. Federal law does not require dietary supplement manufacturers to meet the same safety guidelines that drug manufacturers must.
“Consumers really are guinea pigs,” said Haller, an assistant professor at the University of California, San Francisco.
Adding to the problem, said Haller and other experts, is that bitter orange often is mixed with many herbs. Dexatrim Results, for example, contains bitter orange along with several naturally occurring sources of caffeine, kelp, licorice root and yohimbe bark, which contains a potent stimulant called yohimbine that the FDA says is linked to kidney failure, heart problems and even death.
“I’m especially alarmed that yohimbe is in the mix in some of these products,” Haller said. “I hadn’t been aware of that.”
Another product, Phen-Free, mixes bitter orange with yohimbe bark, cayenne pepper powder, caffeine and an herbal antidepressant called Saint-John’s-wort, among others.
A ‘major unknown’
Dennis McKenna, an herbal medicine expert and senior lecturer at the University of Minnesota’s Center for Spirituality and Healing, said the effect of mixing such herbs is a “major unknown.” Different chemicals in the plants can react with one another, increasing or decreasing the potency, he said.
That can be a problem with stimulants, he said. Many ephedra-free diet aids contain several herbal stimulants along with a substantial amount of caffeine, he said. In effect, this “piles on” stimulants, potentially overwhelming organs such as the heart and increasing the risk for dangerous side effects.
“You’re really stacking the pharmacological cards against you in this situation,” he said.
McKenna said he doesn’t understand why manufacturers have added certain herbs to their products.
One diet aid, for example, contains Piper nigrum a fancy way to describe the black pepper found on many kitchen tables. Fenugreek also used as a seasoning is another common ingredient. Others contain more exotic herbs such as bupleurum root and scutellaria root.
“I’m puzzled as to why many of these are in there,” he said, adding that he sees nothing that would promote weight loss.
Gurley said consumers’ lack of familiarity with herbs or their Latin names can lead to another kind of trouble: drug interactions.
Although many people don’t consider herbs to be drugs, they really are, he said. The active ingredients in them can interfere with over-the-counter or prescription medications.
Saint-John’s-Wort, for example, a common diet aid ingredient, is known to interfere with birth control pills’ potency, Gurley said. The herb may affect how well common cholesterol-lowering drugs such as Lipitor or Zocor work, too.
Stimulants, such as yohimbine, shouldn’t be used by those taking older antidepressants called monoamine oxidase inhibitors, he added.
While most people who use ephedra-free diet aids won’t have a problem, Gurley and other experts said it’s best to err on the side of caution and to lose weight the old-fashioned way: through exercise and by eating less.
If you decide to use the new products, see a doctor first, especially if you have a serious medical problem such as heart disease. Consult a pharmacist about potential drug interactions. Always follow label precautions and dosage guidelines.
“I really hope that these products are going to be safer than ephedra,” Gurley said. “But I haven’t seen anything to convince me that that’s the case.”