(CNN) -- Dietary supplements are commonly used to lose weight and build muscle, but the Food and Drug Administration has issued a warning regarding exposure to a potentially harmful ingredient.
The FDA said in the advisory last week that it is using "all available tools at its disposal" to eliminate supplements containing the stimulant dimethylamylamine, or DMAA, from the market. The agency says DMAA, found in supplements including OxyElite Pro and Jack3d, can cause increased blood pressure, shortness of breath, chest tightening, cardiovascular problems and even heart attacks.
It may be difficult for consumers to tell whether DMAA is an ingredient in their supplement. Different names such as methylhexanamine, 1,3 DMAA or geranium extract could be used.
The FDA says it has received reports of 86 illnesses and deaths associated with supplements containing DMAA as of last week. Illnesses also included nervous system and psychiatric disorders, the agency said, and DMAA could be especially dangerous taken with caffeine.
Dietary supplements with DMAA have been promoted as a natural way to enhance athletic performance and speed up weight loss. According to its website, the FDA does not currently recognize any medical use of DMAA, but it was approved for nasal decongestion in the past.
Unlike with a drug ban, the FDA must go through a series of lengthy scientific and legal steps to ban compounds in dietary supplements, according to its website.
In the meantime, FDA spokeswoman Tamara Ward said that 11 companies have received warning letters from the FDA over the past year asking them to stop marketing products that contain DMAA. All but one -- USPlabs in Dallas, which manufactures OxyElite Pro and Jack3d -- agreed to stop using DMAA in supplements.
The FDA has visited six of the companies that received warning letters. Five had ended production of supplements with DMAA. "The sixth company, which was not in compliance, agreed to recall its product after discussions with FDA," Ward said. Company names were not provided.
In a statement, USPlabs said it "stands behind the safety and quality of its products," citing "eight peer-reviewed published clinical studies detailing the safety of (DMAA) and products containing it, making it one of the most heavily clinically studied dietary ingredients ever."
However, details provided by the company showed that the studies were each conducted with 50 or fewer participants. The FDA said it "has found the information insufficient to defend the use of DMAA as an ingredient in dietary supplements," and it is finalizing a formal response to USPLabs to reflect the findings.
Consumers can report DMAA-related incidents directly to the FDA or the supplement manufacturer. The FDA said consumers should also contact a health care provider if they become ill.Stacey Welsh, Special to CNN