Protein content plays an increasingly important role in the marketing of food products and supplements. A recent Ninth Circuit decision addressed the interplay between the federal labeling regulations and consumer protection claims related to a supplement manufacturer’s protein assertions. In Durnford v. MusclePharm Corp., No. 16-15374, 2018 WL 4938190 (9th Cir. Oct. 12, 2018), the Ninth Circuit held that, even though the manufacturer followed FDA regulations regarding disclosure of the amount of protein in the supplement, the supplement manufacturer’s labeling could still be false or misleading in the manner plaintiff alleged.

In Durnford, a California consumer sued MusclePharm alleging the company artificially inflated the protein content numbers in a popular supplement – the “Arnold Schwarzenegger Series Iron Mass” protein powder – and also misled consumers regarding the composition of that protein. Specifically, plaintiff alleged that MusclePharm’s use of nitrogen-spiking agents resulted in inflated measurement of protein for the nutrition panel and a false or misleading implication regarding the source of the protein in violation of California state-law misbranding theories.

Regarding the allegedly inflated protein measurements, the Ninth Circuit held that the Federal Food, Drug, and Cosmetic Act (“FDCA”) preempted state law misbranding claims based on that theory. The court noted that federal implementing regulations allow for the use of nitrogen as a proxy for protein in the calculation of the protein content listed on the nutrition panel. Because the FDCA concerns the calculation and disclosure of protein amounts, state law theories based on the accuracy of these measurements are preempted.

However, the Court declined to extend the preemption doctrine to plaintiff’s state-law claims based on the product’s protein composition. MusclePharm therefore could not insulate itself from liability for statements regarding the composition of its protein merely because it complied with federal regulations regarding the calculation of the amount of protein.

Regarding the protein’s composition, MusclePharm advertised the product as having a “Muscle Plasma Protein Matrix” consisting of “hydrolyzed beef protein and lactoferrin protein.” Plaintiff claimed that, because a portion of the 40 grams of protein listed in the nutrition panel resulted from the supplement’s nitrogen content, not all of the protein was derived from the natural sources described in the “Muscle Plasma Protein Matrix.” The court agreed, finding that the labeling could mislead a reasonable consumer into believing that all of the 40 grams of protein were derived from natural sources. Thus, even though the process by which protein measurements were calculated was federally regulated, the manufacturer’s statements regarding the protein composition was not regulated, and therefore was not preempted.

The Durnford case illustrates the evolving interplay between FDCA preemption and product labeling claims in the supplement business. For food and supplement manufacturers, this case highlights an important lesson about the multi-layered approach to regulatory and advertising compliance in that regulatory compliance in one respect does not avoid exposure—and may even lead to liability—in other respects. The Drunford case underscores the importance of working with experienced counsel when preparing and finalizing product advertising, which includes a product’s packaging.