This coupon has expired $4.00 for Optimum Nutrition® Whey Protein Isolate. Offer available at Target, Walmart, Kroger. expires on 03/31/19 Other coupons you may be interested in $1.00 for Sangria Senorial (expiring on Monday, 01/02/2023). Offer available at multiple stores. $1.00 for Jarritos (expiring on Monday, 01/02/2023). Offer available at multiple stores.