Costco Lawsuit: Kirkland Fish Oil Heart Health Claims Challenged

Case Overview: A class action lawsuit claims Costco misled consumers by falsely advertising its Kirkland Signature fish oil supplements as supporting heart health, despite scientific evidence suggesting otherwise.

Consumers Affected: California residents who purchased Kirkland Signature fish oil supplements.

Court: U.S. District Court for the Southern District of California

Costco Wholesale Corporation is facing a class action lawsuit alleging that it falsely advertised its Kirkland Signature fish oil supplements as supporting heart health.

The lawsuit, filed by Donna Costan in a California federal court, claims that Costco misled consumers by making this claim on the product labels, despite scientific evidence suggesting that fish oil supplements do not provide cardiovascular benefits and may even pose risks to heart health.

Costan, a California resident, purchased Kirkland Signature fish oil supplements from Costco, relying on the claim that they "support a healthy heart." She alleges that she would not have purchased the supplements, or would have paid less for them, had she known that they did not provide the advertised heart health benefits.

Fish Oil Doesn't Support Heart Health, Lawsuit Claims

The lawsuit challenges Costco's claims that its Kirkland Signature 1000 mg fish oil supplements and Kirkland Signature Wild Alaskan 1400 mg fish oil supplements support heart health. It cites numerous studies, including findings from the National Institutes of Health, indicating that omega-3 supplements, such as fish oil, do not reduce the risk of heart disease or improve heart health markers.

Furthermore, the complaint points to research suggesting that omega-3 fish oil supplements may increase the risk of atrial fibrillation, a heart condition that causes an irregular and often rapid heartbeat.

Costan and other consumers who purchased the supplements argue that Costco's heart health claims are misleading and deceptive, as they are not supported by scientific evidence and may even contradict it. It is claimed that Costco's labeling practices violate California's consumer protection laws, which prohibit false advertising and unfair competition.

Other Supplements Facing Similar Lawsuits

This lawsuit against Costco is not the only recent legal action challenging health claims made by supplement manufacturers. In October 2024, a class action lawsuit was filed against Force Factor, alleging that the company misrepresents the dosage amounts of certain products, misleading consumers and causing them to overpay.

Additionally, in July 2024, a class action lawsuit was filed against Nordic Naturals, alleging that the company deceptively markets its fish oil products as supporting heart health when scientific evidence does not support this claim.

In the Kirkland Fish Oil Supplements class action lawsuit, Costan seeks to represent all California residents who purchased the Kirkland Signature fish oil supplements within the applicable statute of limitations period.

She is asking that Costco cease its allegedly misleading advertising practices and provide refunds to consumers who purchased the supplements under the false belief that they supported heart health. Costan is also demanding an injunction to prevent Costco from making similar claims about its fish oil supplements in the future.

Case Details

• Lawsuit: Costan v. Costco Wholesale Corporation
• Case Number: 3:24-cv-02156-JO-AHG
• Court: U.S. District Court for the Southern District of California

Plaintiffs' Attorneys

• Ruhandy Glezakos, Benjamin Heikali, Joshua Nassir, and Katherine Phillips (Treehouse Law LLP)

Do you take Kirkland Signature fish oil supplements? Share your thoughts on this lawsuit in the comments below.