Costco Faces Lawsuit Over Heavy Metals Found in Protein Powder

Houston shoppers who buy protein supplements at Costco should be aware of a new legal challenge targeting the warehouse retailer, according to FOX 26 Houston. A class action complaint filed against Costco claims that a protein powder carried in its stores contains dangerous concentrations of heavy metals—specifically lead, arsenic, and cadmium—raising food safety questions for the Greater Houston market, where multiple Costco locations serve hundreds of thousands of members across Harris County.

For Houston families, the concern is immediate and practical. Heavy metals such as lead and cadmium are known to accumulate in the body over time, and protein powders are often consumed daily by fitness-minded adults, student athletes, and parents who add them to children's smoothies. Shoppers near the Galleria corridor and throughout Sugar Land who regularly stock up on bulk supplements at Costco may want to check which specific product is named in the suit before their next purchase.

The lawsuit's reach extends across the Houston metropolitan area. Costco warehouses draw members from neighborhoods near Memorial Park, from communities along Buffalo Bayou, and from the sprawling suburbs of Harris County, meaning the potential plaintiff pool in this region alone is substantial. Researchers and dietitians at the Texas Medical Center have long cautioned that unregulated supplement products can carry contaminants not listed on labels.

This case fits a broader national pattern. Consumer advocacy groups have pushed for stricter third-party testing of protein supplements for years, arguing that the supplement industry faces lighter federal oversight than pharmaceuticals. Several prior class actions against other supplement brands have resulted in reformulated products and labeling changes, though outcomes vary widely.

Shoppers should watch for court filings that identify the specific product by name and SKU, that detail will clarify exactly which item to avoid or return. Costco's member services desk can typically process returns on food products without a receipt.