You are being sold time. Fast whey for the "anabolic window," slow casein for the night: same protein, different clock. A 2025 trial put thirty untrained older men through twelve weeks of lifting, with 40 grams of protein post-workout, the same 40 grams before sleep, or no shake at all. Everyone already ate enough protein. Everyone got stronger. Between the groups, no difference at all, and the study was part-funded by a protein-powder brand that still could not find the effect it sells. This is not new: a 2013 meta-analysis showed the post-workout "window" dissolves once you count daily protein. When a 2023 trial finally raced slow casein against fast whey overnight, the casein was not special. Eat enough. Lift something heavy, regularly. Then stop watching the clock. It is measuring how long you will keep buying.