Trends and developments in dietary supplement class action lawsuits in the US
The dietary supplement industry in the US faces an increasing risk of class action lawsuits driven by claims related to labeling, testing, and compliance. Courts continue to apply the reasonable consumer standard when assessing plausibility, and recent decisions emphasizing that context, qualifiers, and disclaimers matter have strengthened that defense. This article examines current trends in class action lawsuits, including challenges to FDA disclaimers for structure/function claims, inaccurate protein %DV declarations, and discrepancies in labeled ingredient amounts. It also addresses lawsuits targeting “greenwashing,” slack-fill, and synthetic ingredient claims and underscoring the importance of substantiated, contextual labeling and proactive compliance strategies.Keywords – dietary supplement, class action, reasonable consumer standard, trends
Introduction
The dietary supplement industry continues to face challenges from consumer class action lawsuits. These lawsuits have increased in number and diversified to include new topics and allegations, presenting a significant risk that has intensified in recent years.1 An examination of trending topics and targets shows shifts in the class action landscape.1 However, noncompliance with US Food and Drug Administration (FDA) requirements, including in technical areas traditionally not a focus for the agency, continues to be a key target for plaintiffs. In addition, the reasonable consumer standard remains a key consideration in how courts determine whether claims are deceptive or misleading. Policy conversations around food – driven largely by the Make America Healthy Again initiative – are also likely to influence the class action landscape, as new stakeholders, such as federal and state policymakers and social media influencers, narrow in on ingredients they deem “questionable,” such as those that are highly processed or synthetic.Manufacturers of traditional food products (i.e., foods other than dietary supplements) continue to receive the largest number of demand letters and lawsuits. However, some of the trends discussed in this article initially focused on foods, then migrated more recently to focus on supplements. In addition, some trends implicate labeling issues unique to the supplement industry, including the mandatory disclaimer required for dietary supplement labels that bear structure/function claims. Technically compliant claims may still be considered false and deceptive.1 However, manufacturers can mitigate some of these risks through diligence and understanding the basis for common plaintiffs’ allegations. Another notable shift favoring the industry is that courts remain unwilling to allow plaintiffs to proceed with unreasonable arguments that ignore the context of a product's label, especially disclaimers, when evaluating allegations of false or deceptive marketing.
Origin of the cases
The FDA closely regulates dietary supplement labels at the federal level. Yet consumer class actions continue to proliferate. This is because most of the product label is considered advertising and is readily challengeable under state-based consumer protection laws.But even FDA-regulated label aspects are challenged by consumer class actions. These cases often implicate an interesting tension that the courts continue to navigate. The Federal Food, Drug, and Cosmetic Act (FDCA) does not provide a private right of action, meaning individuals cannot sue a company for noncompliance with the FDCA and the FDA’s implementing regulations. To avoid preemption, plaintiffs usually frame their claims under state consumer protection, false advertising, or unfair competition laws, arguing that the defendant’s conduct would be misleading under both state law and the FDCA. The key is that these suits do not seek to impose requirements different from or in addition to the FDCA but instead claim that the defendant’s violation of federal standards also constitutes a violation of parallel state-law duties, typically through the state’s version of the FDCA, known as a mini-FDCA. Courts typically allow such parallel claims to proceed if they are genuinely based on state law and not a veiled attempt to enforce the FDCA privately. Thus, FDA compliance can sometimes mitigate risk but is not a full bar against class actions.
The reasonable consumer standard and notable developments
Reliance on state-based consumer protection laws typically invokes the reasonable consumer standard, and courts will dismiss cases early if they are based on something that would not deceive an ordinary consumer. Therefore, even if the label violates the FDCA and there is some argument that it is misleading or deceptive, it may not necessarily pass the reasonable consumer standard. Some jurisdictions, such as California, have had a more permissive approach to the reasonable consumer standard and tend to construe the standard with great deference to plaintiffs/consumers. However, a string of recent Ninth Circuit Court of Appeals cases has revitalized the reasonable consumer argument as a strong defense.- In Moore v. Trader Joe’s Co., the court affirmed the dismissal of a putative class action against Trader Joe’s, holding that labeling its honey as “100% New Zealand Manuka Honey” did not mislead reasonable consumers even though 57%-62% of the product was derived from Manuka flower nectar.2 The Ninth Circuit highlighted the ambiguity of the claim, particularly in the context of the inherent foraging behavior of bees; that the price was relatively low, signaling moderate concentration; and the inclusion of a grading score that would be considered “moderate” quality.
- McGinity v. Procter & Gamble Co. built upon the Trader Joe’s case and clarified the California precedent that courts may consider back-label or additional packaging information to resolve ambiguity if a front-label claim is ambiguous rather than clearly deceptive.3 This resulted in a dismissal, as the Proctor & Gamble shampoo’s ambiguous front-of-pack claim “Nature Fusion” was resolved by back-label disclosures of both natural and synthetic ingredients.
- The Ninth Circuit further clarified the importance of asterisks and qualifying language in Whiteside v. Kimberly-Clark Corp.4 Here, the court applied McGinty and found the front-of-pack claim “plant-based” with nature-themed imagery for the Kimberly-Clark product was not ambiguous and could convey it was entirely plant-based. However, some versions of the claim bore an asterisk leading to disclosure of the exact percentage of plant-based content. The court held that, for products without qualifying asterisks, the front label could plausibly mislead a reasonable consumer, precluding resolving the issue at the pleading stage. However, for products featuring an asterisk with a clear qualifier and corresponding disclosure, the context made deception implausible as a matter of law.
These three cases underscore that labels must be considered in context – not isolation – and that cases pivot on whether a front-label claim is unambiguously misleading or reasonably ambiguous and thus resolvable by further packaging information. These cases only bolster defensive arguments and provide important guidance for claim generation, such as using fanciful terms and providing defining context.
Recent trends affecting the supplement industry
More recent class action lawsuits span a range of theories of alleged “deception.” However, as discussed below, some of the trends unique to dietary supplements do not involve “traditional” consumer class action allegations about nutrient content claims, “natural” claims, or flavor declarations. Instead, plaintiffs are focused on labeling they deem lacks appropriate warnings or contains misplaced disclaimers. They are also challenging the labeled amounts of dietary ingredients and, in some cases, are using product testing to identify alleged mislabeling.FDA disclaimer for structure/function claims
A notable trend over the past year has been an increase in the number of complaints (and numerous nonpublic demand letters) citing noncompliance with 21 CFR §101.93.5 The section requires, among other things, that dietary supplement labels or labeling bear structure/function claims that include the following statement (or its plural form in the case of multiple claims): This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Subsection (d) of the regulation further requires that the disclaimer is linked to the structure/function claim(s) using a symbol – offset in a box if the disclaimer is not adjacent to the claims – and placed on each panel of a product label or each page in labeling where the structure/function claim appears.6 Plaintiffs have seized on this last requirement in particular, alleging that dietary supplements that fail to include the required disclaimer on the same panel as any structure/function claims are deceptively labeled because consumers might reasonably believe the products have been evaluated and approved by the FDA for therapeutic purposes. In addition, plaintiffs allege that such products are misbranded, unapproved drugs and are therefore unlawful.
The regulation requires structure/function claims and the disclaimer to appear on the same panel. However, the FDA has never enforced this requirement, and as such, it has become standard industry practice to include the disclaimer on a different panel, especially with products with limited label space. Unofficial discussions with FDA staff have confirmed that strict adherence to the regulation is not a priority for the agency. Industry has taken this a step further and submitted comments to the FDA requesting that the agency modify the regulation to officially allow more flexibility with the placement of the disclaimer.7 Moreover, recent court decisions – including Whiteside vs. Kimberly-Clark Corp.4 – confirm that reasonable consumers are not expected to ignore asterisks or other symbols signaling that the label includes additional information on the claim.
In the meantime, dietary supplement companies continue to face challenges in this area, mainly in the form of plaintiff demand letters, although there have also been publicly filed complaints. In 2023, Amazon received a complaint over products it fulfills. The plaintiffs argued that several supplements purchased on Amazon.com were “illegal and defective” drugs due to noncompliant or missing structure/function disclaimers, including on the product display pages.8 It is not clear how courts may ultimately rule on this matter should any of these cases be litigated. Thus, companies are left to decide whether to label in strict accordance with the regulation or risk a plaintiff complaint or demand letter.
Protein %DV claims
A growing number of dietary supplement brands are facing complaints and demand letters regarding protein content, which was previously more closely associated with foods. The FDA’s labeling regulations require that, if a protein content claim is made outside the nutrition labeling (e.g., “20 grams of protein”), the percent daily value (%DV) must also be listed in the nutrition labeling and be based on the protein digestibility-corrected amino acid score (PDCAAS).9 The PDCAAS determines the relative protein “quality value,” whereby ingredients with “low quality” protein or that are considered incomplete sources of protein and have a PCDAAS score of zero, would have a lower or zero %DV than the grams per serving divided by the 50-g recommended daily intake would mathematically suggest. This corrected %DV must accordingly be reflected in the supplement (or nutrition) facts.
Numerous complaints and demand letters, often involving plant-based protein powders, have targeted labeling in which the advertised amount of protein is deemed misleading because the PDCAAS-corrected %DV was not declared in the supplement facts or the %DV was miscalculated – thereby mispresenting both protein quantity and quality in the product.10 It might seem that preemption could be a viable defense in these cases, given that FDA labeling regulations are implicated. However, like most class action complaints, the allegations are based on state consumer protection laws and are consistent with federal law, making preemption arguments difficult. In these cases, the best strategy when making a protein call-out is to confirm that the %DV for protein reflects the PDCAAS and ensure that the correct testing and computation methods are used as described in the regulation.
Discrepancies in labeled amounts
Another growing trend in complaints and demand letters centers on dietary supplements claiming to contain a specified amount of a dietary ingredient but seemingly to fall short, sometimes based on testing commissioned by the plaintiff. These cases present a challenge because FDA regulations generally require dietary supplement ingredients to meet 100% of the amount declared on the label, with limited exceptions.11,12
Two recent cases illustrate this trend. In the first case, the product was a magnesium glycinate powder labeled as providing 400 mg of magnesium per one 2,200-mg serving of powder. However, the plaintiff alleged the label was false and misleading because the concentration of magnesium in magnesium glycinate powder is too low to provide the stated 400 mg.13 Notably, this is one of several cases targeting magnesium glycinate supplements based on nearly identical allegations.14 In the other case, the plaintiff challenged the front-label claim of 1,200 mg berberine per serving after its consumer testing found the supplements contained 170-222 mg of berberine per serving.15 The plaintiff argues that “reasonable consumers are grossly misled” by this front-label representation. Previous complaints have also targeted alleged underdosing of Vitamin C, melatonin, and other dietary ingredients.16
Consumer testing to challenge ingredient call-outs and declarations may continue, especially given a recent case that seemed to provide plaintiffs with more leeway for testing. In this case, the plaintiff alleged that the defendant’s BCAA [branched-chain amino acid] dietary supplement powder was mislabeled as having zero calories and zero carbohydrates based on testing that found the product contains 5.68 g of carbohydrates and 51 calories per serving, which exceeds the amounts the FDA allows to be listed as zero on nutrition labels.17 A district court had initially dismissed the case on preemption grounds, finding that the plaintiff had failed to test the product in accordance with the agency’s composite sampling method under 21 CFR 101.36. However, the Ninth Circuit reversed the dismissal and found that reliance on a single sample, using the AOAC [Association of Official Analytical Collaboration] method for carbohydrates and bomb calorimetry for calories that comply with FDA regulations, was sufficient for the case to proceed. This case could fuel additional complaints and demands based on testing because plaintiffs may be able to bring cases based on a single test.
Beyond allegations targeting specific ingredient amounts or testing discrepancies, plaintiffs have also challenged dietary supplement labeling where the ingredient call-outs are based on serving size, rather than the amount per capsule. For example, in a recent case, the plaintiff alleged that several supplements were deceptively labeled because the front label advertised a certain dosage amount (e.g., 1,000 mg) and the number of capsules in each product (e.g., 90 capsules). The plaintiff argued the labeling could lead reasonable consumers to believe that the advertised dosage amount represented the amount per capsule, not per multicapsule serving.18
These plaintiffs’ theories are an important reminder that companies should remain diligent with even the most basic of labeling requirements, such as ensuring ingredient potency and accurate label representation of ingredient quantity vis-à-vis serving size.
Label omission/lack of warnings
Despite many industry-friendly decisions, plaintiff attorneys still test new ways to challenge structure/function claims. Some recent cases regarding omega-3 fatty acids and heart health claims highlight the fact-specific nature of challenges, underscoring that this area of dietary supplement class action lawsuits is not as settled as thought.
Hamzeh v. Pharmavite LLC,19 Clark v. Nordic Naturals, Inc.,20 and Magpayo v. Walmart, Inc.21 all had similarities at the outset. All three are Northern District of California cases, all the products at issue are omega-3 dietary supplements making various claims about supporting heart health, and each of the complaints highlights recently published research that high omega-3 consumption could be harmful to certain aspects of heart health. However, the outcomes of the three cases vary. In Hamzeh, the court rejected a preemption argument, asserting that the plaintiffs’ theory improperly challenged a permissible structure/function claim as a disease claim. The court found that the cited scientific evidence might not be enough when examined factually but was sufficient to plausibly allege omega-3s had no heart health benefit. Clark was also allowed to proceed. The court found the challenge was not preempted because “failure to disclose the harmful aspects of the nutrient’s structure/function is misleading” and the plaintiff had sufficiently alleged a plausible harm. Magpayo, however, was dismissed with prejudice because the plaintiff failed to adequately plead that the omega-3 level in the product was harmful.
The inconsistent outcomes of these cases present challenges because there is no clear rule or guidance for label claims. Given the variability in outcomes, companies should consider any negative scientific outcomes and investigate whether these are related to, or potentially undermine, any claimed benefits.
Additional and emerging trends
The aforementioned examples highlight a few trends affecting the dietary supplement industry. Another area that has been a consistent target across a range of products is alleged “greenwashing” and deceptive environmental, social, and governance claims focusing on product features being “sustainable,” “environmentally friendly,” “recyclable,” biodegradable, “ethical,” and “carbon neutral.” In these cases, it may be true that some aspect of the product or the company’s practices is “green” or socially responsible, given the broad nature of the claims. However, plaintiffs often find other aspects that arguably make the representation false or deceptive. Several suits have also gone after alleged “microcontamination,” where plaintiffs argue that trace amounts of substances such as PFAS, phthalates, and microplastics may pose harm, and claims that the product is “healthy,” “clean,” or “good for the planet” are misleading.22 However, courts seem unwilling to allow these cases to proceed, especially where the plaintiff is only alleging hypothetical harm.There has also been a resurgence in complaints arguing that dietary supplements and other foods contain unlawful amounts of nonfunctional space, or slack-fill, in the packaging. The FDA and state law allow a certain amount of space, provided it meets one of the listed exceptions.23 However, plaintiffs in these cases allege that the exceptions do not apply. They argue that using oversized and opaque packaging misleads reasonable consumers, despite the disclosure of net weight on the label. At this time, it is not clear if these recent cases will proceed beyond the complaint stage.
Outside of claims focused on products and their packaging, complaints focused on deceptive pricing tactics have also been on the rise, implicating a broad range of products. These suits often target alleged false-reference pricing and perpetual sales, add-on fees that are not prominently disclosed, and autorenewal programs that are difficult to cancel or lack prominent disclosures.
One notable and emerging trend to watch stems from the Make America Healthy Again initiative, which targets ultraprocessed foods and certain food chemicals claimed to be linked to chronic disease and health risks. Consumers are also paying more attention to individual ingredients alleged to be synthetic and “undesirable” excipients. For example, in a recent complaint, the plaintiff argued that various melatonin products were falsely labeled as helping consumers “fall asleep naturally.” The plaintiff asserted that melatonin is, in fact, a “highly synthesized chemical which does not exist in nature,” and that the label’s green font and lavender images deceive consumers into thinking it is not synthetic.24 The complaint also cites numerous “synthetic, artificial” ingredients in the products, including calcium phosphate, calcium carbonate, citric acid, hydroxypropyl cellulose, hydroxypropyl methylcellulose, malic acid, maltodextrin, magnesium stearate, silicon dioxide, sodium citrate, stearic acid, and titanium dioxide. As the media, consumer watchdogs, and even social media influencers highlight “unhealthy” or “synthetic” substances, dietary supplements containing these ingredients may end up on plaintiffs’ radar.
Understanding how these trends have evolved and where they might be headed can help dietary supplement companies stay ahead of these challenges. Beyond this, reviewing the entire context of a product’s labeling to draw out all potential claims and messaging – particularly any reasonably implied claims – to determine what can be substantiated remains the best strategy to mitigate risk and defend against a demand letter or complaint.
About the authors
Rend Al-Mondhiry, JD, is a partner and cochair of the regulatory practice group at Amin Wasserman Gurnani LLP, where she advises dietary supplement, food, cosmetic, and over-the-counter drug companies on a broad range of FDA and Federal Trade Commission (FTC) regulatory and compliance matters. Al-Mondhiry earned her law degree from the Dickinson School of Law, Pennsylvania State University, and is admitted in the District of Columbia, Pennsylvania, and New Jersey. She can be contacted at [email protected]
Jennifer M. Adams, JD, is a partner at Amin Wasserman Gurnani LLP and leads the advertising practice. She advises dietary supplement, food, cosmetic, over-the-counter drug, and animal product companies on compliant FDA and FTC marketing practices and advocates with respect to challenges from the FDA, FTC, state attorneys general, competitors, the National Advertising Division, and consumer class actions. Adams has a food science background and is admitted in Illinois and California. She can be contacted at [email protected]
Citation Al-Mondhiry R, Adams JM. Emerging trends in dietary supplement class action lawsuits in the US. Regulatory Focus. Published online 30 October 2025. https://www.raps.org/News-and-Articles/News-Articles/2025/10/Trends-and-developments-in-dietary-supplement-clas
References
All references were last checked and verified on 17 October 2025.
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- Moore v. Trader Joe’s Co., 4 F.4th 874, 882–84 (9th Cir. 2021). https://cdn.ca9.uscourts.gov/datastore/opinions/2021/07/15/19-16618.pdf
- McGinity v. Procter & Gamble Co., 69 F.4th 1093, 1097–99 (9th Cir. 2023). https://cdn.ca9.uscourts.gov/datastore/opinions/2023/06/09/22-15080.pdf
- Whiteside v. Kimberly-Clark Corp., 91 F.4th 1070, 1077–79 (9th Cir. 2024). https://cdn.ca9.uscourts.gov/datastore/opinions/2024/07/17/23-55581.pdf
- Certain types of statements for dietary supplements. 21 CFR 101.93. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-101/subpart-F/section-101.93
- Certain types of statements for dietary supplements, Placement. 21 CFR §101.93(d). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-101/subpart-F/section-101.93#p-101.93(d)
- Council for Responsible Nutrition. Request for information (RFI): Ensuring lawful regulation and unleashing innovation to make America healthy again. Dated 14 July 2025. Accessed 8 September 2025. https://crnusa.org/sites/default/files/weekly/25-07-17/CRN%20Comment_HHS_RFI_Deregulation_Final.pdf
- Li et al. v. Amazon.com Services LLC, Case 4:23-cv-00441-JST (N.D. Cal).
- Nutrition labeling of food, “Protein.” 21 CFR §101.9(c)(7). https://www.ecfr.gov/current/title-21/part-101/section-101.9#p-101.9(c)(7)
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- Food and Drug Administration. Dietary Supplement Labeling Guide: Chapter IV. Nutrition Labeling. Current as of 1 April 2025. Accessed 8 September 2025. https://www.fda.gov/food/dietary-supplements-guidance-documents-regulatory-information/dietary-supplement-labeling-guide-chapter-iv-nutrition-labeling#4-43
- Ade et al. v. Hard Eight Nutrition LLC d/b/a BulkSupplements.com, 25-cv-1656 (D. Md.).
- Wallin v. Naturelo Premium Supplements LLC, Case No. 3:22-cv-05960-GC-DEA (D.N.J.)
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- Campos v. Haleon US Inc. et al., Case No. 4:24-cv-08057-KAW (N.D. Cal.).
- Scheibe v. ProSupps USA, LLC, 141 F.4th 1094 (9th Cir. 2025). https://cdn.ca9.uscourts.gov/datastore/opinions/2025/06/23/23-3300.pdf
- Kodaira v. Wholesome Story, LLC, Case No. 2:2025cv02456 (C.D. Cal.).
- Hamzeh v. Pharmavite LLC, Case No. 4:24-cv-00472-HSG, 2025 WL 930567 (N.D. Cal. Feb. 26, 2025).
- Clark v. Nordic Naturals, Inc., Case No. 5:24-cv-04058-EKL, 2025 WL 3813337 (N.D. Cal. June 5, 2025).
- Magpayo v. Walmart Inc., Case No. 3:24-cv-01350-WHO, 2025 WL 993456 (N.D. Cal. Mar. 10, 2025).
- Castillo v. Prime Hydration LLC, Case No. 3:23-cv-03885(N.D. Cal.)..
- Misleading containers. 21 CFR § 100.100. https://www.ecfr.gov/current/title-21/section-100.100
- Perkins, et al. v. The Procter & Gamble Co., Case No. 3:25-cv-00035 (S.D. Cal.).
