Kobra Labs The Bull Mass Gainer is available in apple flavored. The Bull Mass Gainer is a protein supplement that helps you gain muscle mass. Building muscles requires an excess of calories, so The Bull mass gainer is used to give the body the required nutrition while promoting weight gain. The Bull mass gainer is out on the market today for people who want their bodies to look muscular and toned. It has carbohydrates, and other vitamins and minerals required for a person’s nutritional requirements. To ensure that you push yourself to greater physical heights during your training, the product includes several minerals in the formula to help your body function properly. The Bull Mass Gainer has extra enzymes, which help to promote better digestion.