The Amazon listing says it’s kosher but there’s no actual hashgacha on the bottle and I double checked on OU website as well.
Here are the ingredients:
Milk Protein Isolate, Cocoa Powder (Processed with Alkali), Magnesium Phosphate, Salt, contains less than 2 % of the following: Casein Hydrolysate, Milk Minerals, Vitamin and Mineral Blend (Dl-Alpha Tocopheryl Acetate [Vitamin E], Zinc Glycinate Chelate, Pyridoxine Hydrochloride [Vitamin B6], Vitamin A Palmitate, Folic Acid, Phytonadione [Vitamin K1], Cholecalciferol [Vitamin D3]), Sucralose, Natural and Artificial Flavor, Sodium Ascorbate
Kosher