Serious Mass Weight Gainer
Optimum Nutrition

Serious Mass Weight Gainer

High Energy Protein Powder Contributing to Muscle Growth
Loaded with 1258 kcal, 250g of Carbs, & 25 Vitamins and Minerals
8.5  out of 10  (1,136 Reviews)
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Product Overview

Serious Gains Serious Taste!

Gold Standard Whey Container

Serious Mass is the ultimate in weight gain formulas, with 1250 calories per serving and 50 grams of protein to support muscle growth and repair. This instantised powder makes the ideal post work-out and between meals shake for sizing up your goals.

Serious Mass provides you with the tools you need to pack on the pounds and when coupled with serious weight room effort develop your physique to the fullest.

24g Protein

50g Protein

Tasty Foods

Muscle Support


1250 Calories


Weight Gain

Ratings & Reviews

Serious Mass Weight Gainer
Overall Rating
1,136 Ratings
Verified Buyer Rating
442 Ratings
Average Flavor Rating
7 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.
Feb 14, 2020
Verified Buyer
  • 9 Banana

I’ve used chocolate for too long and the banana was a good change up! The guy below saying the banana is awful, not true. It pretty much tastes like banana laffy taffy! So if you like those, you like the banana. Other than that, it’s just calories to gain weight.

Dec 20, 2019
  • 10 Banana

it works! not much more to say!

Nov 23, 2019
Verified Buyer
  • 9 Chocolate

it tastes good

Nov 19, 2019
  • 9 Cookies and Cream

nice product <a href="#">serious mass</a>

Nov 13, 2019
Verified Buyer
  • 8 Vanilla
Nov 02, 2019
Verified Buyer
  • 7 Chocolate

Last year, I started going to the gym 3 days a week for lacrosse. I'm a teen, I've been growing quite a lot. Last year I was 5'7 at 115, So somewhat small, but once the year was over I was 6'0 at 125. I didn't really know how to gain weight fast enough to keep up with my height. This lead to me seeing very little progress in the gym and in my overall physique. I really hated getting called skinny and underperforming in the gym so I decided I needed to gain some weight. I started using this about a month ago, starting at 130lb, and now I'm 140. I didn't just use the shake alone though. My recipe is as follows: *16oz of milk *3-4 tablespoons of peanut butter *One cup of protein powder (half the overall serving size) *1 banana *and 3ish scoops of chocolate ice cream (I know it's not great but it tastes like sh*t without) -Overall calories for this is around 1700 and the protein is 62g I take two of these a day along with my normal diet so I'm taking in around 5000 calories a day. I'm also training 4 days a week with 1-2 days of cardio a week So if you're trying to bulk and are skinny, I would recommend

Sep 22, 2019
Verified Buyer

Very Good Product. I recommend it. I have a question though, the expiring date is DD/MM/YY or MM/DD/YY? Thank you in advance for your help

Sep 13, 2019
Verified Buyer
  • 10 Vanilla

Vanilla is the best flavor and it mixes well with water, milk or in smoothies. Definitely prefer this over the Optimum Pro Gainer.

Aug 17, 2019
Verified Buyer
  • 10 Strawberry

I’m happy with this product. Best food for my muscles 👍

Jul 13, 2019
  • 10 Chocolate

So, I was about 53kg and I started gym seriously in January 2019 and started taking this and within 3 months of taking and finishing the product, I gained 20kg.

Jul 12, 2019
  • 10 Vanilla

This stuff is a game changer. I went from making home made weight gain shakes using bananas peanut butter and nuts and being on the toilet for days while switching to this and really seeing results. I gained a lot of mass since taking this as well as eating more and I have to say this stuff is incredible. I really see a difference when I stop taking it as I become like a raisin but this keeps my shoulders broad and bulked up. Now the flavor isn’t great let’s be honest and the fact it froths up and you have to wait at least an hour for it to turn to liquid is a little annoying but honestly when your an extomorph and you need to gain weight you’ll deal with it cause this product does work. It’s even better when you add bananas and strawberries or even blueberries taste good with it. I try to drink this five days a week at least it’s my holy grail , and really has helped me a lot so thank you serious mass. I went from skinny and eating everything never seeing any results to actually gaining weight . From a skinny twig this is a game changer thank you!!!

Jul 03, 2019
  • 10 Banana


Jun 20, 2019
Verified Buyer
  • 2 Chocolate

The chocolate taste is terrible! It’s the only reason for a low review.. we’ll see if the product helped in 5-6 weeks

Jun 18, 2019
Verified Buyer
  • 9 Chocolate
  • 7 Chocolate Peanut Butter
  • 2 Banana

Alright so the product itself is the best going around & if you workout 4-5x/week, taking 1-3 FULL servings/day (approx 3500 cals/day) from this Mass Gainer will get you SERIOUS MASS. I started with 140lbs & gained close to 30lbs in 2 months of heavy diet (whole foods) + this product. Now about the flavors: 1) Banana: stay away! This was my first flavor & had to ask for a return but they don't do returns out of the US so had to finish the bag somehow. Almost felt like throwing up after every serving. 2) Chocolate: BEST I've tried so far. It's not too sweet, not too thick & tastes very pleasant. Easy to finish the bag. 3) Chocolate Peanut Butter: Just fine. Wasn't as good as Chocolate but was nowhere as bad as Banana. If you like your chocolate drinks sweeter, go for this one as it is definitely sweeter than the regular Chocolate flavor.

Jun 13, 2019
Verified Buyer
  • 10 Chocolate Peanut Butter

Ordered this 3+ times so far and its great results if you're consistent with drinking it at least once a day. Drank it 2-3x a week and was still able to gain 5lb in 2months and i have fast metabolism too. Flavor is great, way better than any i've ever tasted and i've tried the vanilla and cookies and cream but still doesn't beat this. I mix it with soy milk cause i'm lactose tolerant. i'd for sure recommend putting in a few ice cubes to make it less thick

2 Sizes
2.73 Kilograms
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5 Flavors
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Was:  € 26,09
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Price: € 20,87  (€ 2,61 / Serving)
Flavor Rating: 7.9
Loaded with 1258 kcal, 250g of Carbs, & 25 Vitamins and Minerals

What's in Optimum Nutrition Serious Mass Weight Gainer

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 Weight Gainer:

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.

Flavoured Ready to Mix Powder with Protein, Carbohydrates, Vitamins, and Minerals, with Sweetener.

Made in the UK

OPTIMUM NUTRITION: 4 Waterside, Kingswood Avenue, Citywest Business Campus, Dublin 24, Ireland

* 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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