Serious Mass
Optimum Nutrition

Serious Mass

High Energy Protein Powder Contributing to Muscle Growth
Loaded with 1258 kcal, 250g of Carbs, & 25 Vitamins and Minerals
8.6  out of 10  (1,106 Reviews)
2 Sizes
2.73 Kilograms
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4 Flavors
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Price: £20.24  (£2.53 / Serving)
Flavor Rating: 8.0
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Product Overview

What is serious mass?

Serious Mass is the ultimate weight gain formula.* With 1,250 calories per serving and 50 grams of protein for muscle recovery, this instantized powder makes a sizable post-workout and between meals shake.* Serious Mass gives you the tools you need to pack on pounds and - when coupled with serious weight training - develop your physique to the fullest.*


  • Adding Calories Has Never Been This Easy or Tasted So Good
  • 1,250 Calories
  • 50 Grams of Blended Protein
  • Over 250 Grams of Carbohydrates with No Added Sugar
  • Enhanced with Creatine, Glutamine, and Glutamic Acid
  • 25 Vitamins and Essential Minerals

How is it different from other gainers?

serious mass - weight gain formula - 50g of protein. pro complex gainer - lean gain formula - 60g of protein.














Ratings & Reviews

Overall Rating
1,106 Ratings
Verified Buyer Rating
419 Ratings
Average Flavor Rating
6 Flavors
Top Rated Flavor
Chocolate Peanut Butter
By clicking the button above, you agree to entering the Reviews section. Products in the Store are not intended to diagnose, treat, cure, or prevent any disease.
Nov 15, 2018
Verified Buyer
  • 5 Cookies and Cream
  • 9 Chocolate
  • 7 Chocolate Peanut Butter

This product works so well, all I would recommend is eat a clean diet around it to keep the bodyfat down as much as possible and also workout hard you'll gain some mass. Also chocolate is the best flavor in my opinion.

Nov 11, 2018
  • 10 Vanilla

On day 47 of 90 the resulting mass is sufficient.

Oct 29, 2018
  • 10 Chocolate
  • 7 Cookies and Cream

Great product to get extra calories throughout the day and bulk up! I recommend taking one scoop at breakfast, and one scoop in the evening (after workout). Pairs very well with a creatine supplement (I use it with Muscletech Creactor capsules). Chocolate tastes great, cookies and cream smells pretty weird and has a chemically after taste.

Oct 17, 2018
Verified Buyer
  • 10 Chocolate Peanut Butter

Best Product ever. Love it.

Oct 15, 2018
No written review.
Sep 21, 2018
Verified Buyer
  • 10 Chocolate

There are several body builders in my family. I have been using this protein for several years now. I haven’t been to the gym in 9 months and lost 10-15lbs. I just purchased another bag because I know I will get quick results. I can’t wait to come home and see it at my door step!! I’m so excited to gain my weight back. I know this mass protein will get me there quick!! Hands down the best!! Good Luck!!

Sep 19, 2018
Verified Buyer
  • 10 Chocolate
  • 8 Chocolate Peanut Butter
  • 5 Vanilla

I had it once per day (one scoop, with breakfast) and was able to gain about 10 lbs in 2 months. The key is not to pack up weight too fast or else most of them are simply just fat.

Sep 06, 2018
  • 9 Banana

I took the banana flavor three times last year. After my second tub I noticed I had definitely filled out more and some of my lifts went up as well. Now that I've been off of it for a year I can tell you that it definitely works. I was up to 185. Now I'm down in the 165-170 range. It does contain a lot of carbs and sodium so if your diet isn't good (mine isn't the best) you will gain fat as well as muscle. You have to work out with it and try and limit your soda and fast food. The banana flavor was good and I used a standard shaker cup. I had no problems with the mix ability. However, the serving size is two heaping scoops which, in my opinion, is overkill. I saved more of the product by cutting the serving down to one scoop or one and a half. Still put on 20 lbs in five months. Would recommend for the hard gainer.

Sep 04, 2018

Cookies and cream flavour: It smells like a cleaning product, the tastes not so bad, though. Better mixed with water than milk. It mixes ok, not great. It seems to have a lot of sugar, because you feel a rush after taking it very noticeable. It works in terms of gains, but I've been using it for 3 weeks and I'm getting pimples all over my face and back. So I'm guessing my body doesn't like some of the ingredients. I'm sure it's this gainer, because that's the only food I've changed in the last 3 months. I keep a very strict diet.

Aug 30, 2018
Verified Buyer
  • 8 Cookies and Cream

Superior product at a great price! The cookies and cream isn't quite as tasty as ather products like syntha6 but easy to put down a few times a day. Gains are very iminent after just a bag.

Aug 24, 2018
  • 10 Cookies and Cream

I have used the Serious Mass High Protein Weight Gain product for approximately 2 months. I have gained well over 15 lbs. My wife also tells her patients families about my weight gain and refers them to your website. It's the best thing that I have tried and suggest you buy it and give it a shot. It works !!! Joseph Marana AZ

Aug 17, 2018
  • 10 Chocolate
  • 10 Chocolate Peanut Butter
  • 10 Banana
  • 2 Strawberry
Aug 17, 2018
  • 9 Chocolate

gain 8 kg in 4 week

Aug 15, 2018
  • 10 Chocolate Peanut Butter

Best tasting protein.

Aug 10, 2018
  • 10 Banana

Omg! My first time using protein shakes and my first time using it made me felt like an adrenaline rush. This was good now I'm looking forward to some post workout drinks

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2.73 Kilograms
2.73 Kilograms
8 Servings | £2.53 Per Serving
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5.45 Kilograms
5.45 Kilograms
16 Servings | £2.11 Per Serving

What's in Optimum Nutrition Serious Mass

6 Lbs. Banana
Supplement Facts
Serving Size2Scoops(334g)
Servings Per Container8
Per 334g
Energy 5273kJ
Protein 53.1g
Total Carbohydrate 251.4g
Of Which Sugars 29.7g
Total Fat 4.4g
Of Which Saturates 1.3g
Of Which Trans Fat 0g
Dietary Fiber 0g
Sodium 605mg
Vitamin A 299.3mcg
Vitamin D 1.9mcg
Vitamin E 3.5mg
Vitamin C 21.9mg
Thiamin (Vitamin B1) 0.5mg
Riboflavin (Vitamin B2) 0.6mg
Niacin (Vitamin B3) 6.7mg
Vitamin B6 0.7mg
Folic Acid 71.3mcg
Vitamin B12 0.5mcg
Biotin 54.8mcg
Pantothenic Acid (Vitamin B5) 2.1mg
Potassium 1,229mg
Chloride 649mg
Calcium 556.2mg
Phosphorus 190.7mg
Magnesium 74.1mg
Iron 4.3mg
Zinc 4.8mg
Copper 0.6mg
Manganese 0.7mg
Selenium 26.8mcg
Chromium 130.4mcg
Iodine 66mcg
Creatine Monohydrate 1g
L-Glutamine 501mg
Glutamine Peptides 501mg
Choline Bitartrate 607.9mg
Inositol 250.5mg
Maltodextrin, Protein Blend (Whey Protein Concentrate*, Calcium Caseinate*, Egg Albumen), Flavorings, Mineral Blend (Di-Potassium Phosphate, Sodium Chloride, Ferric Pryophosphate, Zinc Oxide, Copper Gluconate, Manganese Sulfate, Chromium Chloride Hexahydrate, Potassium Iodide), Whey Powder*, Medium Chain Triglycerides, Creatine Monohydrate, Color (Curcumin), Choline Bitartrate, L-Glutamine, Glutamine Peptides, Acidity Regulator (Malic Acid),, Inositol, Vitamin Blend (Dextrose Monohydrate, Ascorbic Acid, Vitamin E Acetate, Niacinamide, Biotin, Vitamin A Acetate, Calcium-D-Pantothenate, Pyridoxine Hydrochloride, Folic Acid, Cholecalciferol, Thiamin Hydrochloride, Riboflavin, Cobalamin), Sweetener (Sucralose).
* From Milk
Allergen Information:
Contains Milk, Egg, Wheat (Gluten)

Directions For Serious Mass:

Add two heaping scoops of Serious Mass to a blender filled with 24 oz (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 24 oz (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-management 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 and support muscle growth as well as contributing to a high-calorie diet.

Post-Workout: Begin drinking 1/2-1 serving of Serious Mass 30-45 minutes following exercise to support muscle growth. Before Bed: Drink 1/2-1 serving of Serious Mass about 45-60 minutes before bed to provide nutrients to help maintain 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.

Warnings: Do not exceed the recommended daily dose. Keep out of reach of children. Do not take this product if you are pregnant or nursing a baby. Check with a qualified healthcare professional before using this product if you are under 18 years of age or if you have any known or suspected medical condition(s) including diabetes, hypoglycemia, and/or if you are taking any prescription or OTC medication(s). Food supplements should not be used as a substitute for a varied diet. Store in a cool, dry place.

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
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