On April 24, the U.S. Food and Drug Administration (FDA) issued warning letters to 10 manufacturers and distributors of dietary supplements containing dimethylamylamine (DMAA). DMAA is commonly found in sports and weight-loss supplements.

FDA stated in the letters that DMAA, also known as geranium extract or methylhexanamine, was not submitted by any of its distributors as a new dietary ingredient (NDI). By law, manufacturers or distributors desiring to use a new ingredient in supplements must notify the FDA with safety data before it can be formulated in dietary supplements. This procedure must be completed 75 days before marketing the dietary supplement containing the NDI.

The agency also told the 10 manufacturers (including USP Labs, iSatori, Muscle Warfare and Nutrex Research) that synthetic DMAA cannot be classified as a dietary ingredient and therefore cannot be an active ingredient in dietary supplements. Last, FDA questioned the safety of DMAA, stating that the herb is known to narrow blood vessels and arteries, which could lead to elevated blood pressure and consequently, a variety of cardiovascular conditions including tightness of breath and heart attacks.

The 10 companies contacted have 15 days (by mid-May) to respond to FDA with explicit steps they will take to address the issues presented in the warning letters.

However, not all agree with these issues presented by the FDA. Michael McGuffin, president of the American Herbal Product Association (AHPA), states that the AHPA disagrees with the FDA’s ruling that synthesized constituents of botanicals cannot be classified as dietary ingredients: “The agency's position on this ignores the fact that synthesized vitamins, minerals, amino acids, and botanical constituents were already marketed at the time DSHEA was passed. In AHPA’s view, if DMAA exists in geranium through the plant's own synthesis processes, human-synthesized DMAA is also a lawful dietary ingredient.” AHPA also questions the FDA’s statement on the safety issues surrounding DMAA.

GNC, whose stock prices fell after the warning letters became public, disagreed with the FDA’s concerns over the safety of the ingredient as well. GNC told the Pittsburgh Post-Gazette, “When taken as directed, we believe that DMAA has the same effect on the body as drinking two cups of coffee.”

Shortly after the warning letters were issued, several class actions lawsuits were filed in California against DMAA manufacturers, some of which were not targeted by FDA.

Published in WholeFoods Magazine, June 2012