Mass XXX™ - ChocolateChocolate | GNC
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Item # 386585



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Size: 6.2 lb(s).

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You can get even more out of every workout session when you make GNC AMP Mass XXX™ a part of your exercise routine. This protein-packed dietary supplement is clinically proven to help increase lean muscle mass with 40% fewer sets.* Plus, 3g each of Tri-MG Infusion™ and Creatine Matrix Blend help support athletic performance* and muscle protein synthesis^*, while micronized amino acids support key processes crucial to muscle growth and repair.^*

Feature Bullets

  • Clinically proven to help increase lean muscle mass, weight, strength and endurance with 40% fewer sets*
  • 50g of fast-, medium- and slow-digesting proteins, along with 11g of BCAA, 750 calories, plus carbohydrates and healthy fats for science-based nutrition, advanced muscle performance^* and to help maximize gains*
  • Creatine Matrix Blend with 3 forms of creatine may help improve training results and supports muscle protein synthesis^* 
  • Tri-MG Infusion™ is an powerful blend that delivers relentless support for athletic performance*
  • Micronized amino acids help fuel muscles* and support key processes crucial to the growth and repair of muscle^* 
  • Gluten-free dietary supplement
  • Naturally- and artificially-flavored, delicious chocolate taste


In an eight-week, randomized, double-blind, placebo-controlled study of healthy male volunteers, 18 subjects completed 3 sets of resistance training (RT) daily + the macronutrient blend in Mass XXX™, and 16 subjects performed 5 sets RT daily with no supplement. After eight weeks, subjects on the supplement showed equal gains in body weight, fat free mass (FFM), maximal muscle strength (MMS) and muscle endurance (ME) with only 3 sets RT per day compared to the control group who completed 5 sets RT per day.

^When used in conjunction with an exercise program.

*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.



Nutrition Facts
Serving Size  4 level scoop(s)
Servings Per Container  13

Amount Per Serving     % DV

Calories 750  

Total Fat 6g   8%
Cholesterol 100mg   33%
Total Carbohydrate 123g   45%
  Dietary Fiber 4g   14%
Protein 50g   100%
Saturated Fat 4g   20%
Total Sugars 20g  

Calcium 560 mg   43%
Iron 5.1 mg   28%
Potassium 1320 mg   28%

Sodium  720 mg   **
Tri-MG Infusion™  3 g   **
   BETAPOWER® Betaine Anhydrous   **
Micronized Amino Acids  500 mg   **
   Micronized L-Arginine   **
   Micronized L-Leucine   **
Creatine Matrix Blend  3 g   **
   Dicreatine malate   **
   Creatine Ethyl Ester HCI   **
   Guanidinoacetate   **
   Creatine monohydrate   **
   L-Arginine   **
   L-Glycine   **
   L-Methionine   **
Dicreatine malate  890 mg   **
Creatine Ethyl Ester HCL  800 mg   **
Guanidinoacetate  500 mg   **
Creatine Monohydrate  400 mg   **
L-Arginine  300 mg   **
L-Glycine  80 mg   **
L-Methionine  30 mg   **

** Daily Value (DV) not established.
Other Ingredients
Maltodextrin, Protein Blend (Whey Protein Concentrate, Calcium Caseinate, Soy Protein Isolate), Cocoa (Processed with Alkali) , Natural and Artificial Flavor, MCT (Medium Chain Triglycerides), Lecithin, Salt, Acesulfame Potassium, Sucralose
Contains: Milk and Soybeans.
Label (click image to enlarge)

How To Use

As a dietary supplement, mix 4 level scoops (205 g) with 16 fl. oz of cold water or milk. Consume 1-2 servings daily. On training days, consume post-workout. On non-training days, consume first thing in the morning or between meals. Consume ample amounts of water while taking this product.
Consult your physician to using this product if you are pregnant, nursing, under 18 years of age, taking medication, or have a medical condition. Discontinue use two weeks prior to surgery. , Keep out of reach of children.
Store in a cool dry place.
Distributed by:
General Nutrition Corporation
Pittsburgh, PA 15222


4.5 / 5.0
39 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Good stuff does what it says don’t get vanilla way to strong of flavor
July 15, 2019
3 weeks ago
Good taste and easily dissolves with milk or water.
July 14, 2019
3 weeks ago
This is only my first bottle, so as far as effects go I don't think I will notice anything until about mid second bottle. I will say though that this stuff taste amazing (strawberry). It mixes so well too, you don't have to shake but for a couple of seconds and this stuff is to milk shake consistency. I will def be buying again.
July 11, 2019
It has a great taste with a really good result! Make sure you have a bigger bottle to mix it, also highly recommend using milk instead of water when mixing to drink.
July 9, 2019
4 weeks ago
Best weight gainer
June 29, 2019
1 year ago
Inland empire
Really good service
June 21, 2019
3 weeks ago
Great product.
Great taste for a weight gainer. Will keep buying this product over and over.
June 1, 2019
2 months ago
Product vs Market Value
I bought the strawberry flavor and am surprised with the fact that it tastes really good. The marketing of the container looks good.

However, the cost compared to how many servings you actually get (13, yes ONLY 13 servings) for $54 does NOT sit well with me. The disclaimer given for this product states this product was used for an 8 week study. If you quickly do the math based off the study, this product only adds gives you about 1125 calories a week (if you spread the 13 servings out between 8 weeks). If that's the range of additional weight you want to add on a weekly basis and are okay with the price, I'd recommend. I know there's other products for the same cost, that provide higher results.
May 8, 2019
Good little hard for the stomach
May 2, 2019
3 months ago
Makes u strong
Love this stuff
April 20, 2019
3 months ago
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 8 questions Browse 8 questions and 12 answers
Is this the same as your old product 'amplified mass xxx'?
judy d on Jun 5, 2018
BEST ANSWER: The woman at GNC said it was the same, but Rite Aid still has the original black and red container of Amplified Mass XXX........... The outside of the new container is different, the scoop doesn't even remotely resemble the other scooper and the directions for use are different. It tastes the same. I just purchased the new container so I'm guessing it's the same with 50 grams of protein per serving. Will soon know.
What about banana flavor????it's the best
Rick C on Jun 17, 2018
Is this safe for college athletes?
A shopper on Oct 15, 2018
BEST ANSWER: Yes I’m 14 and was suggested to take it by an gnc worker
How long before you see results?
A shopper on Oct 3, 2018
BEST ANSWER: Id say about a month. Works best when your a being consistent with taking it and working out.
Will this help men over 50 years of age??
Stan S on Jun 16, 2018
BEST ANSWER: I'm 55. I've been packing on pounds and muscle. Put the beer can down and pick up the barbell.
how was the taste?
A shopper on Jun 11, 2018
BEST ANSWER: It tastes amazing it's my favorite I been buying this brand for a while now love it highly recommended
What replaced Amplified Wheybolic Extreme 60? Thanks it was my favorite about 5 yrs ago.
D K on Mar 17, 2019
can this be a meal replacement shake?
A shopper on Jun 28, 2019
BEST ANSWER: No it cannot replace a meal