Shoppers are continuing to rush the toilet paper and other aisles at Costcos in the U.S. and Canada as coronavirus cases in both countries grow.
U.S. cases have topped 1,000, while Canada's government reported 103 cases as of Wednesday.
But many Americans of all risk levels are feeling the need to stockpile.
"PLEASE NOTE: Due to increased demand at this time, availability may be limited," the in-app note said.
As more Americans prepare to hunker down at home, major retailers are putting limits on the number of purchases on select items such as hand sanitizer and disinfectant wipes to curb stockpiling.
Target stores throughout the country implemented product quantity limitations over the weekend with signs put up to communicate the new policy.
"Due to high demand and to support all customers, we will be limiting the number of sanitization, cold and flu-related products to 5 each per order. Your order may be modified at the time of pickup or delivery," the company said on its website.
FOX Business' Cortney Moore and The Associated Press contributed to this report.