Description What is Instant Mass® Heavyweight? Instant Mass® Heavyweight is a protein shake designed specifically for hardgainers and athletes wanting a very high quality source of protein and complex carbohydrates. Each serving provides a huge protein, carbs, and calories. In order to provide such a huge dose of protein, we’ve created the Quattro® protein blend, which is four of the best types of whey protein together with our slow-releasing protein Micellar Casein. Instant Mass® Heavyweight delivers a blend of complex carbohydrates to provide your body with a serious source of fuel without simply adding sugars, corn syrups, or fructose. It also contains 18 added vitamins and minerals to support your physical goals before, during and after training. Who is it for? Instant Mass® Heavyweight has been created for hardgainers and athletes who train intensely but find it difficult to gain muscle and weight.