It depends on the specific casein protein powder. Some casein protein powders are lactose-free, meaning they contain little to no lactose. This can be beneficial for individuals who are lactose intolerant, as it allows them to still get the benefits of casein protein without experiencing the digestive discomfort associated with lactose intolerance.

However, not all casein protein powders are lactose-free, so it is important to check the ingredient list and label carefully to determine the lactose content of a specific product. If you are lactose intolerant, it may be advisable to use a non-dairy source.