Serious Mass
Optimum Nutrition

Serious Mass

Protein Powder Weight Gainer*
Loaded with 1,250 Calories, 250g of Carbs, & 25 Vitamins and Minerals to Pack on Pounds*
8.4 out of 10  (1,100 Reviews)
2 Sizes
6 Lbs.
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5 Flavors
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Competitor Price: $45.79
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Our Price: $27.48 ($3.44 / Serving)
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Flavor Rating: 7.5

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
1,100 Ratings
Verified Buyer Rating
398 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.
Verified Buyer
  • 9 Chocolate
  • 10 Chocolate Peanut Butter
  • 9 Cookies and Cream
  • 4 Vanilla
  • 8 Strawberry

I have been using this product off and on for a couple of years now. I burn through many calories throughout the day and I'm a hard gainer, so the bulk and easy aborsbing calories in this product is great. I just wish it had a little more protein in the carb/protein ratio. Overall, it's a great product for the price.

  • 8 Chocolate

After training for a Half Marrathon I lost over 10 lbs with the mass gainer I put 15 lbs back on in muscle in a week. I would recomend it if you're trying to make some gains.

  • 9 Chocolate

Im gonna be as honest in this review as possible. Im really one of those underweight teens before i started working out. Im 5'6 and i weighed 112 pounds. Then i started working out and used serious mass. Taste wise, i think the chocolate was delicious. At first, i wasnt gaining weight, but then i noticed it's because this product is so thick and hard to drink that it made me eat less. So i decided to take only half a serving a day (1scoop) so that i can eat more. For the First two weeks after taking 1 scoop a day i gained 10 pounds. The next week i gained an aditional 5 pounds. Yes i did gain "mass" in general, but The only i thing i hate about it was that 70% of the mass i gained was fat and only 30% was muscle. Tho it did increase my strength, i think i'd get on's gold standard instead of this thick smoothie like serious mass to gain lean muscles

Verified Buyer
  • 3 Cookies and Cream

Ok so I've been on this product for a while and it's helped me gained at least 10lbs. Ive always gotten chocolate peanut butter, and the chocolate one. I purchased the cookies and cream one... man to me it's a really bad flavor. Doesn't even taste like cookies and cream. I recommend this product just not this flavor! I wonder if I can do an exhange

Verified Buyer
  • 10 Vanilla

Detailed, long, and honest review for potential buyers: This is great for skinny guys looking to gain weight. Using this, as well as eating more food in general I went from 140 - 155 in less than a month of using it daily. It has to be mentioned that a fair bit of that is in fat, not lean muscle, but hey all things considered not bad. The recommended serving size of "two HEAPING scoops" is pretty dumb. One, the scoop is buried like sunken treasure in the bag, making it almost impossible to get out with the risk of wasting powder since this powder in particular is very sticky. Sticks to hands easily, the scoop, etc. Not a con, but makes you wonder why it may be sticky sometimes opposed to their regular gold standard Whey. So, instead of doing that I use my other scoop from the regular GS Whey from ON, with an average of 3 scoops. I'm estimating that's about half of the 1250 potential calories, coming to about 600 - 700 calories per shake, especially when using milk instead of water. Overall, really good for a weight gainer, at times a bit chunky, but if that affects you your a *****. Just chug it.

† This price is the retail price for this product found at one or more retail websites in the last 30 days. The price may not include shipping cost, tax, sale or promotional prices, or discounts such as member pricing. Prices may change. verifies this price every 30 days.

What's in Optimum Nutrition Serious Mass

6 Lbs. Banana
Supplement Facts
Serving Size2 HeapingScoops(334g)
Servings Per Container8
Amount Per Serving In Water % Daily Value
Calories 1250
Calories From Fat 35
Total Fat 4g 6%*
Saturated Fat 2.5g 13%*
Cholesterol 80mg 27%
Total Carbohydrate 254g 85%*
Sugars 21g
Protein 50g 100%*
Vitamin A 5000IU 100%
Vitamin C 60mg 100%
Vitamin D 200IU 50%
Vitamin E 30IU 100%
Thiamin 4.8mg 320%
Riboflavin 4mg 235%
Niacin 50mg 250%
Vitamin B6 5mg 250%
Folic Acid 400mcg 100%
Vitamin B12 10mcg 167%
Biotin 300mcg 100%
Pantothenic Acid 25mg 250%
Calcium 630mg 63%
Iron 5mg 28%
Phosphorus 460mg 46%
Iodine 150mcg 100%
Magnesium 140mg 35%
Zinc 15mg 100%
Selenium 70mcg 100%
Copper 1mg 50%
Manganese 2mg 100%
Chromium 120mcg 100%
Molybdenum 75mcg 100%
Sodium 430mg 18%
Potassium 940mg 27%
Creatine Monohydrate 1g
L-Glutamine 500mg
Glutamine Peptides 500mg
Choline (As Choline Bitartrate) 250mg
Inositol 250mg
PABA (Para-Aminobenzoic Acid) 5mg
* Percent Daily Values are based on a 2,000 calorie diet
† Daily Value not established
Other Ingredients:
Maltodextrin, Protein Blend (Whey Protein Concentrate, Calcium Caseinate, Egg Albumin, Sweet Dairy Whey), Natural And Artificial Flavors, Vitamin And Mineral Blend (DiPotassium Phosphate, Magnesium Aspartate, DiCalcium Phosphate, Calcium Citrate, Ascorbic Acid, Niacinamide, Zinc Citrate, Beta Carotene, D-Calcium Pantothenate, D-Alpha Tocopheryl Succinate, Selenomethionine, Copper Gluconate, Ferrous Fumarate, Manganese Amino Acid Chelate, Thiamin Mononitrate, Pyridoxine Hydrochloride, Riboflavin, Chromium Polynicotinate, Folic Acid, Biotin, Molybdenum Amino Acid Chelate, Cholecalciferol, Potassium Iodide, Cyanocobalamin), Medium Chain Triglycerides, Lecithin, Malic Acid, Acesulfame Potassium, Sucralose, FD&C Yellow #5.
Allergen Information: Contains Milk, Egg, Wheat (Glutamine Peptides) And Soy (Lecithin) Ingredients.

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-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.

Warnings: 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).

* 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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