About this item

• CLINICALLY PROVEN STRENGTH AND MASS GAINER: GNC AMP Mass XXX mass gainer combines high-quality protein powder, key nutrients, and science-backed innovations—including MyoTOR, creatine, and BETAPOWER—to fuel proven results and performance.
• INCREASE LEAN MUSCLE MASS WITH 40% FEWER SETS: Mass XXX’s macronutrient blend delivers 50g of protein, including naturally occurring EAAs, plus carbs, and healthy fats—and it’s clinically proven to help get better results out of workouts.
• IMPROVE MUSCLE STRENGTH IN AS EARLY AS 2 WEEKS: MyoTOR is clinically proven to accelerate improvements in strength with as little as 2 weeks of training and included in every serving of Mass XXX mass gainer.
• ENHANCED FOR IMPROVED STRENGTH AND STAMINA: Take resistance training to a new limit with MyoTOR’s clinically studied support for improved muscle endurance and BETAPOWER’s athletic performance benefits.
• BANNED SUBSTANCE TESTED: Unlike most mass gainers with proprietary blends, Mass XXX is certified Banned Substance Tested and formulated to help you gain mass without compromising your goals.