- All-in-One Weight Gainer To Simplify Your Supplement Routine: One Stop Xtreme has been formulated to replace the use of numerous supplements, allowing you to take only one protein shake to support muscle growth alongside a balanced healthy diet
- High-performing Weight Gain Shake: One Stop Extreme high protein powder delivers a hit of protein, creatine, BCAAs and other beneficial nutrients to bodybuilders looking to make gains – contributing to the growth and maintenance of muscle mass
- Boosting Stregth and Endurance: Reflex mass gainer protein powder contains creatine, that increases physical performance in successive bursts of short-term, high intensity exercise – With LAB2PRO friendly bacteria and Digezyme digestive enzymes
- Nutritional Excellence: contains L-Leucine, Beta Alanine, Betaine Anhydrous and Taurine, along with essential vitamins and minerals aiding the maintenance of normal protein synthesis, function of the immune system and testosterone production
- Premium Ingredients: Reflex only uses whey protein sourced from grass-fed cows, ensuring a high-quality weight gain protein powder that mixes well, with a smooth texture and a delicious taste
- Produced in an Informed Sport Registered Facility: Suitable for vegetarians and Halal certified – Hormone-free, zero added sugars, artificial colors or soy protein, assuring a conscientious choice of food supplements for weight gain
Protein Powders
Reflex Nutrition One Stop® Xtreme – Serious Mass Gainer – All in One Protein Powder – 55g Protein, 10.3g BCAAs, 5,000mg Creatine – Muscle Building Protein Shake (Chocolate Perfection, 4.35kg)
£50.99 (as of 03/31/2026 03:55 PST - DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product.)
One Stop Xtreme has been formulated to replace the use of numerous supplements, allowing you to take only one protein shake to support muscle growth alongside a balanced healthy diet
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