Quest Nutrition lawsuit claims protein shakes contain lead above legal limit

A California woman filed a class action lawsuit against Quest Nutrition on March 11, 2026, alleging the company's ready-to-drink protein shakes and milkshakes contain lead at levels that exceed California's legally established safe daily limit yet carry no warning labels as required by state law.

Tinamarie Barrales, a Los Angeles County resident, says she regularly bought Quest Protein Milkshakes in the vanilla flavor from a Target store in South Gate, California, from 2023 through September 2025.

According to the complaint, Barrales relied on the product labels when deciding to buy the shakes, including the lack of any Proposition 65 warning. She claims she would not have purchased the products at all, or would have paid less for them, if she had known the products contained lead at levels above the state's safe harbor limit.

California's Proposition 65, known as the Safe Drinking Water and Toxic Enforcement Act of 1986, requires businesses to warn Californians before exposing them to chemicals known to cause cancer or reproductive harm. The State of California officially recognized lead as one of these chemicals.

The state set a daily safe harbor limit, called the Maximum Allowable Dose Level, or MADL, at 0.5 micrograms per day for lead. According to the complaint, the Quest products at issue expose consumers to lead at levels well above this threshold without carrying the required warning on their labels.

Which Quest products are at issue?

The complaint targets seven Quest products:

• Quest Protein Shakes in four flavors:
• Vanilla
• Chocolate
• Salted caramel
• Coffee

• Quest Protein Milkshakes in three flavors:
• Vanilla
• Chocolate
• Strawberry

Quest sells the ready-to-drink bottled beverages at major retailers across California.

What did the lab testing find?

The plaintiffs conducted independent laboratory testing in November 2025. According to the lawsuit, an ISO-accredited laboratory, meaning one that has met internationally recognized quality and testing standards, found the Quest Protein Shake in vanilla flavor, sold in a 32-milliliter bottle, contained 0.002 micrograms of lead per serving. The complaint alleges that consuming one bottle daily results in a lead intake of 0.65 micrograms per day. That figure is 130% of the Proposition 65 daily limit.

The numbers are even higher for the milkshake product. The lab found the Quest Protein Milkshake in vanilla flavor, sold in a larger 414-milliliter bottle contained 0.007 micrograms of lead per serving. According to the complaint, daily consumption of one bottle leads to a lead intake of 2.9 micrograms per day. That is 580% of California's 0.5 microgram safe harbor daily limit.

What does this mean for Quest consumers?

Under Proposition 65, businesses that expose Californians to listed chemicals at or above the safe harbor levels must provide a "clear and reasonable warning" before that exposure occurs. According to the complaint, none of the seven Quest products carry this required warning. Without it, the lawsuit argues, consumers have no way of knowing they could ingest lead at levels the state has determined are above a safe threshold.

The complaint further argues that consumers could not reasonably protect themselves from this harm on their own. Detecting lead in a consumer product requires laboratory testing, which is not something the average shopper can do at the point of purchase.

The proposed class in this lawsuit includes all people who purchased any of the seven named Quest products within California for personal or household use in the four years before the complaint was filed.

The complaint asks the court for several types of relief on behalf of the class. First, it requests an injunction, which is a court order that would prevent Quest from selling the products without compliant Proposition 65 warning labels. The lawsuit also seeks restitution for consumers who bought the products, disgorgement of profits Quest earned from the alleged violations and civil penalties under California Health and Safety Code Section 25249.7(b) for each unlawful consumer exposure to lead. Additionally, the complaint calls for the destruction of any misleading advertising materials and product labels, a recall of the named products, payment of attorneys' fees and costs and a jury trial.

The allegations in the complaint are the plaintiff's claims and have not been proven in court.