Several recent cases arising under the federal Food, Drug, and Cosmetic Act (“FDCA” or the “Act”), 21 U.S.C. § 301 et seq., highlight the usefulness of preemption as a defense against putative class actions concerning drugs, cosmetics, dietary supplements, medical devices, and other consumer products subject to the Act. The FDCA provides for exclusive enforcement by the FDA and has no private right of action. Implied preemption also extends to state law claims based on allegations that the defendant violated FDA regulations. Buckman Co. v. Plaintiffs’ Legal Comm., 531 U.S. 341, 349 n.4 (2001) (citing 21 U.S.C. §337(a)) (“The FDCA leaves no doubt that it is the Federal Government rather than private litigants who [is] authorized to file suit for noncompliance with” the FDCA’s substantive provisions). This article addresses recent federal cases supporting FDCA preemption of state law claims that require the fact finder to improperly assume the FDA’s enforcement power, particularly in the class action context. 

Recent Cases Show FDCA Implied Preemption Remains a Strong Defense

In Nexus Pharms., Inc. v. Cent. Admixture Pharm. Servs., 48 F.4th 1040 (9th Cir. 2022), the plaintiff, developer of Emerphed, an FDA-approved drug, alleged that the defendant (an Illinois compounding pharmacy) violated several states’ consumer protection statutes by selling “essentially a copy” of Emerphed without FDA approval. Affirming dismissal of the plaintiff’s claims, the Ninth Circuit held, in part, that “[t]o permit [the plaintiff] ‘to proceed with a claim that Defendants violated [the FDCA] when the FDA did not so determine would, in effect, permit [the plaintiff] to assume enforcement power which the statute does not allow and require the finder of fact to make a decision that the FDA itself did not make.’” Id. at 1049 (citation omitted). While not a class action, Nexus demonstrates that robust application of the doctrine of implied preemption can also counter efforts by companies to use the FDCA to block what they see as unfair competition. Further, federal courts have recently relied on Nexus in dismissing putative class actions on FDCA preemption grounds, as discussed below. 

In DiCroce v. McNeil Nutritionals, LLC et al., 82 F.4th 35 (1st Cir. 2023), the First Circuit affirmed on implied preemption grounds the District of Massachusetts’ dismissal of a putative class action complaint alleging that defendant’s labeling of Lactaid dietary supplements was misleading. Plaintiff Kristin DiCroce alleged that, because lactose intolerance is a disease and Lactaid purports to “treat” lactose intolerance, Lactaid is a drug deceptively marketed as a dietary supplement. The First Circuit held that the plaintiff’s claims were impliedly preempted by the FDA’s statutory enforcement authority set forth in the FDCA. The court reasoned that, even though the plaintiff’s claims were asserted under state law, the complaint “hinges on [plaintiff’s] assumption that Lactaid’s labels violate the FDCA’s labeling requirements and are therefore misleading to consumers.” Id. at 42. 

Likewise, in Wilson v. Colourpop Cosmetics, LLC, No. 22-cv-05198-TLT, 2023 U.S. Dist. LEXIS 185688, at *3, 23 (N.D. Cal. Sep. 7, 2023), plaintiff Kacey Wilson sought to bring a nationwide class action seeking recovery under state consumer protection statutes on the theory that the defendant’s makeup products contained harmful ingredients allegedly designated by the FDA as “unsuitable and unapproved for cosmetic use in the eye area.” Id. at *18. After initially facing dismissal on implied preemption grounds, plaintiff amended the complaint to omit any references to the FDCA. The court nonetheless found the claims impliedly preempted, explaining that the “substance” of the claims still improperly sought “to enforce the FDCA.” Id. at *23. 

Most recently, in Collyer v. Catalina Snacks Inc., No. 23-cv-00296-AMO, 2024 U.S. Dist. LEXIS 9637, at *14 (N.D. Cal. Jan. 18, 2024), the court applied Nexus to a food-related putative class action. Plaintiff Karen Collyer alleged that the packaging of defendant’s “Keto Friendly Cereals” was misleading under California consumer protection statutes because the cereals allegedly do not contain certain ingredients pictured on the packaging. The court concluded that plaintiff’s claim was impliedly preempted under the FDCA: “Collyer’s claim that the cereal labels at issue are unlawful is based on violation of the [UCL, Bus. & Prof. Code 17200, et seq.], which expressly incorporates the FDCA and regulations as state law.” Id. at *17. The Court thus dismissed Collyer’s UCL “unlawful” claim without leave to amend. Id. at *21.

These decisions make clear that when a plaintiff’s claims are premised on alleged violations of the FDCA, they are preempted—even when the claims themselves are brought under state laws.

Future Challenges on the Horizon?

At least one plaintiff is challenging this status quo. On February 22, 2024, the plaintiff in DiCroce filed a petition for certiorari in the United States Supreme Court asking the Court to clarify “how the doctrine of implied preemption should be applied in cases brought under state law based on allegations that defendants had violated FDA regulations?” Without a circuit split, the petition for cert appears to be a longshot, but we will continue to monitor the case.


As it stands, the implied preemption doctrine provides an effective method to attack putative class actions asserting state consumer protection claims based on alleged violations of the FDCA at the motion to dismiss stage, before incurring substantial costs. But the defense bar should keep a close eye on recent efforts by class action plaintiffs’ counsel to challenge application of preemption to state law causes of action.