Looking for the best protein shakes for men? Give our protein shakes a try! WonderSlim’s protein shakes are 100 calories and 15 grams of protein. The first ingredient is medical grade protein (calcium caseinate), which is designed to keep men fuller for longer. Our hunger-quashing protein shakes boast an incredible 15 grams of protein per serving combined with 24 essential vitamins and minerals in every delicious shake - perfect for busy men.