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Optimum Nutrition Serious Mass Weight Gain Powder

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Optimum Nutrition Serious Mass Review

Fitness Savvy took a look online and discovered 5,141 online user reviews for Optimum Nutrition Serious Mass Gainer Weight Gain Powder. Overall, this mass gainer scored 4.2 out of 5, with Chocolate Peanut Butter being the most liked flavour. Users were pleased with the macro profile, high-calorie content and mixability. Negative remarks include a chemical taste, oversized scoop and poor mixability of the strawberry flavour.

  • Easily add weight using this product
  • Great macro profile
  • High calories
  • Mixes well with water
  • Fantastic as a meal replacement

  • Some people note that the strawberry flavour doesn’t mix as well as others such as vanilla or banana
  • A few users reported stomach ache side effects
  • Several users thought it had a “chemical” taste to it
  • Scoop is very big and might make adding it to your shaker difficult

Optimum Nutrition Serious Mass Weight Gain Videos

Why Choose Optimum Nutrition Serious Mass?

Some people really struggle to add weight. This can be particularly troublesome if you’re looking to bulk up and add some serious muscle mass. It’s certainly not uncommon for some of these individuals (often referred to as hard gainers, or ectomorphs) to actually lose weight while trying to get big!

If this is you, you’re probably looking for a high-calorie weight gain supplement to help you out. Optimum Nutrition’s Serious Mass is far from disappointing when you look at calorie content – over 1,250 per serving! But is this the best one for you?

With so many mass gainer supplements on the market, we’ve worked hard to highlight what makes this product great. As you would probably expect, there are very good reasons for why Serious Mass weight gainer is so popular:

1250 Calories Per Serving

When mixed with water, Serious Mass protein powder contains a whopping 1,250 calories! Insane, we know. But the fun doesn’t stop there: If you’re not impressed, and still looking to seriously increase your calories even more, then just mix with low-fat milk. This takes the total to a staggering 1640 calories per serving!

250g of High GI, Fast-Acting Carbohydrates

Slow-release carbs such as oats will fill you up quicker. If you’re a hard gainer, this is the last thing you want! In addition, research shows that fast-acting, high GI carbs are preferable, post-workout, to promote glycogen uptake by muscles. This means that the energy will be stored in muscle cells to be used exclusively for the muscle.

24 Vitamins & Minerals

There is no point in adding another 1,250 calories to your daily intake without increasing important vitamins and minerals. You’ll be glad to hear that Optimum Nutrition Serious Mass contains 24 all-important vitamins and minerals, to ensure your body is able to properly process the macronutrients. Check out the Nutrition tab to find out more about the levels contained.

Recovery & Performance Enhancing Formula

If you’re looking to maximise your muscle-building capabilities, you should consider what other important ingredients are in your weight gainer, or all in one protein powder.

ON Serious Mass Gainer includes creatine (proven to increase performance), l-glutamine & Glutamine Peptides (increase protein synthesis), as well as well-researched neurotransmitters such as Choline and Inositol, and MCTs (medium-chain triglycerides) for increased fat breakdown

50g of Blended Protein Per Serving

For typical protein shakes, the protein per serving is usually the most important thing to consider. With a mass gainer, protein is still very important, but we believe the ingredients mentioned earlier are the most important to consider.

However, this product contains a good blend of whey protein concentrate (which has a more balanced nutritional profile than isolate or hydrolysate), calcium caseinate, and egg protein.

Optimum Nutrition Serious Mass Best Price & Discount Codes

If you’re looking for the best Optimum Nutrition Serious Mass price, then you’re in the right place. At Fitness Savvy, we compare prices from top retailers. With prices changing every day, you should always check back with Fitness Savvy before you buy weight gain supplements.

We’ve also included discount codes and vouchers which might be relevant to this item. Check out the offers and deals below to see if you can save even more on this product.

Predator Nutrition Logo
Free UK Delivery on orders over £40
Free Standard Delivery (2-3 day service) in the UK...Show More
Free Standard Delivery (2-3 day service) in the UK, available for orders over £40. Excludes Northern Ireland, The Scottish Highlands & Islands. Show Less
Predator Nutrition Logo
Buy 1, Get 1 HALF PRICE - Carb Killa bars
Add any two, mix 'n' match, and get the second half price.
Add any two, mix 'n' match, and get the second half price. Show Less

Alternative Optimum Nutrition Whey Protein

Read reviews and compare prices on the Optimum Nutrition whey protein range.

How & When to Take Serious Mass

Add two heaped 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 non-fat 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.

Note: For best results use Serious Mass combined with intense weight training (3-5 times per week) and a sensible whole foods diet. Also, keep in mind that sufficient recovery between workouts impacts your ability to gain lean mass. Allowing at least 48 hours between workouts involving the same body parts is recommended.

Where to Buy Optimum Nutrition Serious Mass

ON Serious Mass comes in two sizes – 5.4 kg (12 lbs) and 2.7 kg (6 lbs) and is available to buy online and in-store. Outlets selling this product include:

  • Amazon
  • GNC
  • Holland & Barrett
  • Discount Supplements
  • Monster Supplements
  • Bodybuilding Warehouse
  • Optimum Nutrition
  • eBay

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Alternative Mass Gainers

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Specification: Optimum Nutrition Serious Mass Weight Gain Powder

Primary Protein Form



Optimum Nutrition


Banana, Chocolate, Chocolate Mint, Chocolate Peanut Butter, Cookies & Cream, Strawberry, Vanilla



Carbs Per Serving

252 g



Creatine Per Serving

1 g

Calories Per Serving


Fat Per Serving

4.5 g

Glutamine Per Serving

1 g

Macro Ratio (Protein, Carbs, Fat)


Protein Per Serving

50 g


5.45 kg


Nutritional Information Per Serving:

  • Energy: 1252 kcal / 5247 kJ
  • Protein: 49.9 g
  • Total Carbohydrates: 252.1 g
    • of which Sugars: 21.3 g
    • of which Dietary Fiber: 2.8 g
  • Fat: 4.8 g
    • of which Saturates: 1.9 g
  • Salt: 1.238 g

Amounts Per Serving:

  • Vitamin A: 299 mcg
  • Vitamin D: 2 mcg
  • Vitamin E: 4 mg
  • Vitamin C: 22 mg
  • Thiamin: 0.5 mg
  • Riboflavin: 0.6 mg
  • Niacin: 7 mg
  • Vitamin B6: 0.7 mg
  • Folic Acid: 71 mcg
  • Vitamin B12: 0.5 mcg
  • Biotin: 55 mcg
  • Pantothenic Acid: 2 mg
  • Potassium: 1397 mg
  • Chloride: 653 mg
  • Calcium: 351 mg
  • Phosphorus: 167 mg
  • Magnesium: 83 mg
  • Iron: 4 mg
  • Zinc: 3 mg
  • Copper: 0.65 mg
  • Manganese: 0.5 mg
  • Selenium: 34 mcg
  • Chromium: 130 mcg
  • Iodine: 51 mcg
  • Sodium: 495 mg


  • Maltodextrin, Protein Blend (Whey Protein Concentrate, Calcium Caseinate, Egg Albumin),Fat Reduced Cocoa Powder, Flavorings, Mineral Blend (DiPotassium Phosphate, Sodium Chloride, Ferric Pyrophosphate, Zinc Oxide Copper Gluconate, Manganese Sulphate, Chromium Chloride Hexahydrate, Potassium Iodine), Medium Chain Tri-glycerides, Creatine Monohydrate, Choline Bitartrate, L-glutamine, Glutamine Peptides (gluten), whey powder, inositol, vitamin blend (ascorbic acid, vitamin E-acetate, niacinamide, biotin, vitamin A-acetate), calcium-D-pantothenate, pyridoxine hydrochloride, folic acid, cholecalciferol, thiamine hydrochloride, riboflavin, vitamin b12, sweetener (sucralose)

Recommended Usage of Optimum Nutrition Serious Mass Weight Gain :

  • Add two heaping scoops (334 g) of serious muscle mass to a large blender filled with 24 fl. oz. of cold water or milk.
  • If desired, add ice and other ingredients, cover and blend on a high speed for 45-60 seconds – or until thoroughly mixed.
  • New users may find it beneficial to begin with one half of a serving daily for the first week, gradually increasing to one or more full servings several times a day.

Suitability / Allergen Information:

  • Contains: gluten, egg, milk
  • May contain: peanuts, soy, nuts

5141 reviews for Optimum Nutrition Serious Mass Weight Gain Powder

4.2 out of 5
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