In a win for implied preemption, the Ninth Circuit recently affirmed dismissal of supplement marketing claims under California’s Unfair Competition Law (UCL).  The case, Bubak v. Golo, LLC, No. 24-492 (9th Cir. Oct. 9, 2025), held that the plaintiff’s UCL claim was impliedly preempted because it depended entirely on alleged violations of the federal Food, Drug, and Cosmetic Act (FDCA), which may be enforced only by the federal government.

Plaintiff asserted a UCL claim premised entirely on allegations that Golo violated the FDCA—which is incorporated into California’s Sherman Food, Drug, and Cosmetic Law (Sherman Law)—by representing that its dietary supplement can mitigate or prevent a disease.  The Ninth Circuit held that claim was impliedly preempted because it “necessarily requires litigating the alleged underlying FDCA violation,” and “the plain text of the FDCA leaves that determination in the first instance to the FDA’s balancing of risks and concerns in its enforcement process.”  The Ninth Circuit noted that its decision in Bubak was consistent with its prior holding in Nexus Pharmaceuticals, Inc. v. Central Admixture Pharmacy Services, Inc., 48 F.4th 1040 (9th Cir. 2022).

Notably, the Ninth Circuit declined to extend its more recent decision in Davidson v. Sprout Foods, Inc., 106 F.4th 842 (9th Cir. 2024), which we previously covered here.  In Davidson, a split panel broke with the logic underlying Nexus by holding that the FDCA does not preempt Sherman Law claims that are fully parallel with the FDCA.  The Bubak court distinguished by stating that the claim in Davidson did not “require litigating questions that are reserved for the FDA, because the violation was plain” in that case.  Here, however, as in Nexus, “further analysis is needed to determine whether Golo’s marketing actually violated the FDCA.”

In a separate concurrence, Judge Callahan suggested that Davidson should be overruled.  Judge Callahan noted that Davidson created an intra-circuit split and argued that the FDCA does not carve out a “plain violation” exception to its bar on private enforcement.  Even if it did, there is no meaningful distinction between the violations in these cases, each of which required examining the marketing at issue to determine if it violates FDA regulations. 

While unpublished, Bubak underscores the continuing uncertainty in the Ninth Circuit after Nexus and Davidson.  Helpfully, however, both the memorandum opinion—which narrows Davidson to “plain” violations—and the separate concurrence—which openly calls for the court to revisit Davidson—lay the groundwork for advocating for a broader view of preemption in future cases.