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Optimum Nutrition Serious Mass 2.72 KG (6 LB)

£50.99 £34.99
(You save £16.00)
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Optimum Nutrition Serious Mass 2.72 KG (6 LB)

Weight Gainer




ON’s Serious Mass is the ULTIMATE weight gain formula. If you find it difficult to gain weight, Serious Mass will help you develop the physique you've always wanted!

What Does It Do?

Each delicious shake delivers an incredible 1,250 calories, but no added sugar. This includes 50g of blended protein to support building muscle and 250g of carbs to fuel your workouts.

When Is The Best Time To Enjoy My Shake?

Simply mix up 2 scoops with milk or water in your ON shaker and enjoy between meals, post-workout and/or before bed. 




Add two heaping scoops of Serious Mass to a blender filled with 710 ml of water. Blend for 45-60 seconds. Then add a few ice cubes and, if desired, other calorie-contributing ingredients and blend for an additional 30-45 seconds.

Tips: Mixing two scoops of Serious Mass with 710 ml of nonfat or low fat milk instead of water will give you a thicker, creamier, higher-calorie shake. New users may find if beneficial to begin with 1/2 of a serving daily for the first week and then gradually increase to 1 or more full servings several times a day.

Serious Mass is a substantial weight-gain supplement that can be used to feed serious calorie needs in a variety of different ways.

Between Meals: Drink 1/2-1 serving of Serious Mass between meals to maintain positive nitrogen balance and support a high-calorie diet. Post-Workout: Begin drinking 1/2-1 serving of Serious Mass 30-45 minutes following exercise to support maximum recovery. Before Bed: Drink 1/2-1 serving of Serious Mass about 45-60 minutes before bed to provide nutrients to recovering muscle throughout the night.




Below values based on Serious Mass 5.455kg Strawberry

  • Container Size: 2727g

  • Serving Size: 2 scoops (334g)
  • Servings Per Container: 8
  • Container Size: 5455g
  • Serving Size: 2 scoops (334g)
  • Servings Per Container: 16

  • Amount Per Serving
  • Total Calories 1250
  • Protein 50g
  • Total Carbohydrates 252g
  • -Sugars 20g
  • -Dietary Fiber 4g
  • Fat 4.5g
  • -Saturates 1.5g
  • Cholesterol 80mg
  • Vitamin A 5000 I.U.
  • Vitamin C 60mg
  • Vitamin D 200 I.U.
  • Vitamin E 30 I.U.
  • Thiamin 4.8mg
  • Riboflavin 4mg
  • Niacin 50mg
  • Vitamin B6 5mg
  • Folic Acid 400mcg
  • Vitamin B12 10mcg
  • Biotin 300mcg
  • Pantothenic Acid 25mg
  • Calcium 590mg
  • Iron 8mg
  • Phosphorus 430mg
  • Iodine 150mcg
  • Magnesium 140mg
  • Zinc 15mg
  • Selenium 70mcg
  • Copper 1.6mg
  • Manganese 2mg
  • Chromium 120mcg
  • Molybdenum 75mcg
  • Sodium 410mg
  • Potassium 1560mg
  • Choline (as choline bitartrate) 250mg
  • Inositol 250mg
  • PABA 5mg
  • Creatine Monohydrate 1g
  • L-glutamine 500mg
  • glutamine Peptides 500mg


Maltodextrin, Protein Blend (Whey Protein Concentrate, Calcium Caseinate, Egg Albumen, Sweet Dairy Way), Creatine Monohydrate, L-glutamine, glutamine Peptides, Choline (as Choline Bitartrate), Inositol, Paba (Para-Aminobenzoic Acid), Artificial Flavor, Vitamin & Mineral Blend (Di-Potassium Phosphate, Magnesium Aspartate, Di-Calcium Phosphate, Calcium Citrate, Ascorbic Acid, Niacinamide, Zinc Citrate, Beta Carotene, d-Calcium Pantothenate, d-alpha Tocopherol Succinate, Selenomethionine, Copper Gluconate, Ferrous Fumarate, Manganese Amino Acid Chelate, Thiamin Mononitrate, Pyridoxine Hydrochloride, Riboflavin, Chromium Picolinate, Folic Acid, Biotin, Molybdenum Amino Acid Chelate, Cholecalciferol, Potassium Iodide, Cyanocobalamin), Medium Chain Tri-glycerides, Acesulfame Potassium

Please Note: Nutritional facts and ingredients may vary slightly between flavours








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