Costco sales surge as protein products drive strong quarter

Costco’s latest quarter put a hard number on a trend that has been building across grocery aisles and fitness fridges: protein is no longer niche. The warehouse club posted net sales of $69.15 billion for the 12 weeks ended May 10, 2026, up 11.6% from a year earlier, while net income rose to $2.19 billion, or $4.93 per diluted share. Management said shopper interest in GLP-1 medications and protein-focused products helped drive the performance, a sign that the protein boom has moved well beyond the supplement aisle.

The clearest proof came in the specific items moving fastest. Costco said a private-label beef stick was doing “tremendous volume” and offering “tremendous value” to members, while Ron Vachris said Kirkland Signature ultra-filtered protein milk had “just taken off.” Protein snacks and bars also helped offset softness in other food categories, even as lower egg prices weighed on the quarter. Fresh category comparable sales rose in the high single digits, led by meat and bakery, with premium and lower-cost proteins singled out as standouts.

That mix matters because Costco is built to make broad shifts visible. The company said comparable sales rose 9.8% overall and 6.6% excluding gasoline and foreign exchange, while digitally enabled comparable sales increased 21.5%. Costco operated 931 warehouses worldwide as of May 28, including 639 in the U.S. and Puerto Rico, and its membership model funnels huge volumes through a tightly edited assortment of nationally branded and private-label goods. When protein pops there, it is not a fad at the edges. It is a basket driver.

The quarter also showed how Costco is pairing that demand with faster fulfillment and sharper digital merchandising. Same-day delivery averaged under 45 minutes in the U.S., and personalized recommendations contributed nearly $5 billion in ecommerce sales. Membership numbers kept climbing too, with 41.2 million paid executive memberships and 82.9 million total paid members, reinforcing the loyalty that makes premium, high-protein staples easier to scale.

Momentum carried into May, when Costco reported net sales of $24.01 billion, up 14.5% from a year earlier. For a retailer that lives on low margins and high volume, the message was unmistakable: protein has become a mainstream shopping habit, and Costco is now one of the cleanest places to see it.