The class action lawsuit was filed last month in the U.S. District Court for the Southern District of California, citing independent testing commissioned by the plaintiff that allegedly detected approximately 404 mg of omega-3 fatty acids per two-capsule serving.

Cases involving alleged differences between label declarations and product testing are fairly common and relatively easy for plaintiffs' attorneys to pursue, according to Asa Waldstein, founder and principal of Apex Compliance.

"These types of alleged label mismatches are common and somewhat easy for plaintiff attorneys to bring, since label testing is fairly inexpensive, and the 'consumer didn't get what they paid for' argument is relatively simple to make," he told NutraIngredients.