Health Law Daily Wrap Up, DIETARY SUPPLEMENTS—W.D. Wash.: Amazon’s bid to stay dietary supplement labeling class action pending FDA rulemaking denied, (Mar 5, 2026)

By Martin A. Steinberg, J.D.

There is no need for FDA expertise in this case, and prospective agency action would not justify delaying claims under existing labeling regulations.

The federal district court in Seattle denied Amazon.com Services, LLC’s motion to stay a putative class action alleging that dietary supplements sold on its marketplace violated federal labeling requirements, as incorporated into California law, by omitting mandatory DSHEA disclaimers on each panel or page bearing structure/function claims. Applying the Ninth Circuit’s primary jurisdiction framework, the court concluded that three of the four Syntek factors weighed against a stay because adjudicating whether the labels complied with 21 C.F.R. § 101.93(d) presents a conventional judicial task that does not require FDA expertise or resolution of novel regulatory issues. Although the FDA has indicated it may initiate rulemaking to remove the “each panel” requirement, the court found no basis to assume retroactive application. It was determined that efficiency concerns favored proceeding with the three-year-old case. The court therefore denied the motion to stay (Medal v. Amazon.com Services LLC, No. 2:23-cv-01975-JHC (W.D. Wash. Feb. 27, 2026)).

Background. Amazon operates an online marketplace that lists and sells dietary supplements. Plaintiffs allege they purchased various supplements through Amazon between 2019 and 2024 and relied on structure/function claims displayed on the product pages, believing the products had therapeutic value and/or had been reviewed and approved by the FDA. They contend that Amazon systematically listed and sold supplements bearing such claims without including the mandatory DSHEA disclaimer “on each panel or page” where the claim appears, as required by 21 C.F.R. § 101.93(d) and 21 U.S.C. § 343(r)(6), and that the disclaimers must be prominently displayed.

Plaintiffs filed suit in 2023, asserting violations of California’s Unfair Competition Law (UCL), predicated on alleged violations of California’s Sherman Food, Drug, and Cosmetic Law, which incorporates federal food-labeling requirements and makes them identical to federal standards. The court earlier denied Amazon.com Services, LLC’s motion to dismiss the class action lawsuit.

In 2025, HHS issued a Request for Information seeking input on deregulation, and industry groups urged the FDA to rescind the “each panel or page” requirement in § 101.93(d). The FDA subsequently issued a letter indicating it intends to initiate rulemaking to remove that requirement. Amazon moved to stay the case under the primary jurisdiction doctrine pending completion of that anticipated rulemaking.

Legal standards. The court explained that primary jurisdiction is a “prudential doctrine” under which a federal court may, in appropriate circumstances, determine that initial decision-making responsibility lies with the relevant administrative agency rather than the court. See Syntek Semiconductor Co. v. Microchip Tech. Inc., 307 F.3d 775, 780 (9th Cir. 2002). The doctrine applies when a claim is cognizable in federal court but requires resolution of an issue of first impression or a particularly complicated issue that Congress has committed to a regulatory agency. It is not designed to “secure expert advice for courts,” and whether to invoke it is committed to the court’s discretion.

In the Ninth Circuit, courts evaluate four Syntek factors: (1) the need to resolve an issue; (2) Congress has placed that within the jurisdiction of an administrative body having regulatory authority; (3) pursuant to a statute subjecting an industry or activity to a comprehensive regulatory scheme; and (4) requiring expertise or uniformity in administration. In addition, courts must consider efficiency and whether invoking primary jurisdiction would needlessly delay the resolution of claims. Efficiency is described as the “deciding factor,” and the doctrine should not be invoked where it would produce unnecessary delay.

The parties’ positions. Amazon argued that the first Syntek factor was satisfied because the FDA has indicated that it intends to revise 21 C.F.R. § 101.93(d) to remove the “each panel” DSHEA disclaimer requirement, the regulatory predicate for Plaintiffs’ UCL claim under the Sherman Law. It contended that the second and third factors were met because supplement labeling falls squarely within the FDA’s comprehensive regulatory authority. As to the fourth factor, Amazon asserted that allowing the case to proceed risks conflict with imminent agency rulemaking and undermines uniform administration. It further argued that efficiency favored a stay because the FDA’s action could affect class scope and its anticipated preemption defense.

Plaintiffs responded that three of the four factors weighed against a stay. They contended that their claim does not raise a policy question requiring initial FDA resolution, nor does it demand technical expertise beyond the conventional judicial task of comparing label layouts to regulatory text and assessing whether consumers were misled. They argued that any future rulemaking would be prospective only and therefore would not defeat accrued claims. Finally, they asserted that staying a case pending for three years would impair efficiency.

First and second Syntek factors. The court concluded that the first and second factors weighed against a stay. The core issue is whether Amazon violated federal labeling requirements as incorporated into California’s Sherman Law. Compliance with labeling requirements is a matter that federal courts routinely adjudicate. Evaluating Plaintiffs’ claims requires comparing the regulatory text of § 101.93(d) to the labels at issue, a task courts in this Circuit routinely perform without invoking primary jurisdiction.

The court emphasized that such cases are “far less about science than [about] whether a label is misleading.” No issue of first impression or ambiguous regulatory term requires agency clarification. Unlike the “evaporated cane juice” cases or CBD cases, where technical or policy determinations were unsettled, this dispute involves a straightforward application of existing regulatory text. Accordingly, there is no need for the FDA to resolve a threshold issue before judicial review proceeds.

Third Syntek factor. The third factor favored Amazon because dietary supplement labeling falls within the FDA’s comprehensive regulatory scheme. Congress has vested the FDA with the authority to create a uniform national scheme ensuring that food labeling does not mislead consumers. Dietary supplements are a form of food, and thus dietary supplement labeling is a form of food labeling. Plaintiffs do not meaningfully dispute this point.

Fourth Syntek factor. The fourth factor — expertise or uniformity in administration — did not favor a stay. Amazon argued that a conflict could arise if the court enforced the “each panel” requirement while the FDA eliminated it through rulemaking. Plaintiffs countered that regulations are presumed not to apply retroactively absent clear congressional authorization.

The court agreed with Plaintiffs. The FDA letter signaling anticipated rulemaking does not indicate retroactive application. Established Supreme Court precedent holds that congressional enactments and administrative rules are not construed to have retroactive effect unless their language requires it. The court relied on the Supreme Court’s retroactivity framework in Landgraf v. USI Film Products and Bowen v. Georgetown University Hospital, emphasizing that neither the statute nor § 101.93(d) contains language authorizing retroactive application. Neither the statute nor the regulation addresses retroactivity.

The court distinguished the cases cited by Amazon (including CBD and evaporated cane juice cases) as involving novel regulatory contexts in which retroactivity concerns were either speculative or not meaningfully analyzed. Here, by contrast, there was no indication that the FDA intends to engage in retroactive rulemaking. Because Plaintiffs seek to enforce the regulation as it existed when their claims accrued, retroactivity principles protect their claims and eliminate the asserted conflict.

Efficiency considerations. Efficiency was the “deciding factor” for the court. Primary jurisdiction is disfavored where referral would significantly postpone a ruling the court is competent to make. The court noted that rulemaking can take years and that courts routinely decline to invoke the doctrine where delay would be substantial. Given that this case has been pending for three years, and that adjudication involves a conventional judicial determination of regulatory compliance, the court concluded that efficiency favored proceeding rather than awaiting speculative and potentially lengthy FDA rulemaking.

Preemption. The court also rejected Amazon’s argument that anticipated revisions to § 101.93(d) could “inform” or strengthen its implied preemption defense. Under Ninth Circuit precedent, California Sherman Law claims are not impliedly preempted where they seek to enforce standards identical to those imposed by federal law and do not require courts to resolve issues Congress has reserved exclusively to the FDA.

The court reasoned that any future revision to § 101.93(d) would not apply retroactively absent clear congressional authorization. Because Plaintiffs’ claims are based on the regulation as it existed during the relevant time period, they seek to hold Amazon to standards identical to federal requirements then in force. As a result, adjudicating the claims would not require the court to interpret unsettled regulatory policy, compare technical formulations, or intrude on the agency's exclusive determinations.

Accordingly, the court concluded that prospective rulemaking does not create a preemption problem, and the possibility of regulatory change does not justify staying claims grounded in existing law.

The Case is No. 2:23-cv-01975-JHC.

Judge: Chun, J.

Attorneys: Adam R. Shaw (Boies Schiller & Flexner LLP) for Anita Medal. Ariane Rockoff-Kirk (Paul, Weiss, Rifkind, Wharton & Garrison LLP) for Amazon.com Services LLC.

Companies: Amazon.com Services LLC

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