After the Food and Drug Administration last week condemned more than two dozen diet aids and warned consumers not to take them, some Southeast Tennessee pharmacies and nutrition shops said they don’t stock those products or advise their use.

Bearing names like Imelda Perfect Slim, Zhen de Shou and Japan Lingzhi, most of the diet pills appear to come from outside the United States, according to FDA officials.

FDA spokeswoman Rita Chappelle said in a telephone interview that the agency is involved in an investigation to get the listed pills off the market.

“They pose great health risks,” she said. “If consumers have them, they should stop using them immediately. Get checked out by a physician and work with the physician to come up with another plan to lose weight.”

The products, some of which are marketed as dietary supplements, are promoted on various Web sites and in some retail stores. Some claim to be natural or to contain only herbal ingredients, but actually contain potentially harmful ingredients not listed on the product labels. These products have not been approved by the FDA, are illegal and may be potentially harmful, according to an FDA news release.

“Some of these pills contain at least three times the maximum amount of medication allowed by the FDA,” Ms. Chappelle said.

An FDA analysis found that the undeclared active pharmaceutical ingredients in some of these products include sibutramine, a controlled substance; phenytoin, an anti-seizure medication, and rimonabant, a drug not approved for marketing in the United States.

Rimonabant, which is approved in Europe, has been associated with increased risk of depression and suicidal thoughts. Its use has been linked to five deaths and 720 adverse reactions in Europe over the past two years, according to the FDA news release.

Some of the diet pills also include phenolphthalein, a solution used in chemical experiments and a suspected cancer-causing agent, or contain prescription-strength medications that are not included on the label.

“If a person is taking certain medication and mixes it with the listed diet products, it can cause serious, life-threatening consequences,” Ms. Chappelle said.

It could cause heart attack or stroke and affect blood pressure, she said.

Several Southeast Tennessee stores say they don’t carry the product and recommend residents not to take them.

“We don’t carry any of them,” said Tom Goewey, owner of the GNC store in Cleveland.

The GNC store does offer diet supplements. Staff members are trained to ask customers if they’re on any medications and if they’ve taken the diet product in the past, Mr. Goewey said.

“If they’re on any blood pressure or heart medications, we don’t make a suggestion without advising them to talk to their pharmacist because they will know the drug interaction,” he said.

Representatives for the Cherokee Pharmacy & Medical supply store in Cleveland and South Rhea Natural Foods in Dayton, Tenn., said they do not sell or recommend the products.

“There is no magic pill. We just try to get people to eat as many fruits, vegetables and whole grains as possible and to drink as much water as possible,” South Rhea Natural Foods owner Teresa Miller said.

She advises people to proceed cautiously with all diet aids.

“Some have the idea that if it’s all natural, that there can’t be any side effects, but that’s not true. You have to use all products with wisdom,” she said.

Maurice Saliba of Cleveland, president of Wellness Steps of Bradley County and a member of the Obesity Task Force, cautions against all diet pills.

“Ninety-nine percent of all the herbs in pills are a form of caffeine. They may be effective for weight loss, but bad for your health,” Mr. Saliba said.

Many of the pills work by increasing blood pressure, he said. When blood pressure goes up, so does heart rate, and that speeds up the metabolism. So a person sitting on a couch is able to burn more calories by taking a pill.

The danger comes because that person may not be taking in the oxygen needed to support an increased heart rate, he said.

“If your heart rate goes up and you’re not getting the oxygen to support it, you could have a heart attack,” Mr. Saliba said.

The safer alternative is to do physical activity that raises your heart rate, thus raising your metabolism. Being physically active naturally increases oxygen intake, he said.

About 300 people in Bradley County have lost 4,400 pounds by participating in the Wellness Steps program, he said. The group achieved the goal by strength training, doing cardiovascular exercises and controlling their diets.

“You cannot out-work a lousy diet,” Mr. Saliba said.