Do plaintiffs’ attorneys smell blood in the water? A raft of class-action suits recently initiated against dietary supplement manufacturers, alleging deceptive practices in the sale of fish oil products, suggests that they might.

These suits, filed in California federal courts (a favorite jurisdiction for the plaintiffs’ bar), are nearly identical in that they allege that the manufacturers’ fish oil products do not actually contain fish oil. To date, plaintiffs’ class action lawyers have already targeted well-known dietary supplement products, such as Dr. Tobias Omega 3 Fish Oil Triple Strength (by Mimi’s Rock) and GNC-brand Triple Strength Fish Oil (by International Vitamin and Nutra Manufacturing). More litigation may be forthcoming.

The allegations focuses on the process used to create fish oil supplements—transesterification. Transesterification is a chemical process used to obtain fatty acid ethyl esters from fish oil achieved by introducing an alcohol catalyst to the fatty triglycerides.

The lawsuits claim that the transesterification process intrinsically leaves the finished supplement products without any of the Omega-3 fatty acids DHA or EPA. The plaintiffs also allege that the resulting Omega-3 molecules in the finished post-transesterification product are different than the Omega-3 molecules naturally found in fish oil.

Thus, according to the lawsuits, “Once trans-esterified, fish oil is irrevocably transformed, such that it is no longer fish oil and therefore cannot be so named or labeled.” As a result, plaintiffs claim that these products mislead the public with false and deceptive labeling that is in violation of federal and state laws.

The lawsuits are still in their early stages, so their ultimate success remains to be seen. But the potential impact is substantial. Fish oil supplements constitute a large consumer market. Indeed, the lawsuits put that figure at almost $2 billion per year worldwide with an expectation of nearing $3 billion per year by the end of the decade.

Given the sheer size of the market, a lot of dietary supplement manufacturers potentially face copycat suits. And, were the plaintiffs to succeed on their theory that “once trans-esterified, fish oil is irrevocably transformed, such that it is no longer fish oil,” then dietary supplement manufacturers may also have to worry about the Federal Trade Commission pursuing civil liability or even an aggressive Department of Justice considering criminal charges.

Supplement companies can take action to mitigate potential risks from litigation. A manufacturer should always review and ensure adequate and solid substantiation for any and all claims (express or implied) about products.