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Mass XXX™ with MyoTor® - Vanilla (13 Servings)
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Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
Mass XXX™ with MyoTor®  - Vanilla (13 Servings)
$86.99
($6.69 / serving)
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In stock

Mass XXX™ with MyoTor® - Vanilla (13 Servings)

379985
379985 379985
$86.99
($6.69 / serving)
  • PRO ACCESS BOGO 50% Off Mix-and-Match UPGRADE NOW
    close popup
    Offer valid on GNC.com and at participating stores through June 7, 2026. Buy 1, get 1 of equal or lesser value 50% off. Mix and match. Select products only. Must add 2 eligible items to cart for discount. Exclusions may apply. See a Coach in store for details or click on "SHOP NOW" to view specific products included in the sale. GNC PRO ACCESS members only.
In stock
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LOCAL RESTRICTIONS

Due to local weight loss supplement and muscle-building supplements regulations, persons under the age of 18 are prohibited from purchasing this item.

An adult must be present to provide a signature and valid ID upon delivery or pick up in-store.

For New York residents, a $4.99 delivery fee is added in checkout.

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At a Glance
This clinically proven gainer features a powerful blend of 50g protein, 770 calories, and MyoTOR to help you increase lean mass and muscle strength.*
Highlights
  • Gluten Free

Mass XXX™ with MyoTor® - Vanilla (13 Servings)

ITEM # 379985

GNC AMP - Mass XXX™ Clinically Proven Weight Gainer Protein Powder - Vanilla

GNC AMP Mass XXX mass gainer combines high-quality protein powder, key nutrients, and science-backed MyoTOR, creatine, and BETAPOWER—to fuel proven performance.

  • Clinically Proven Gainer: GNC AMP Mass XXX™ mass gainer combines high-quality protein powder, key nutrients, and science-backed innovations—including MyoTOR®, creatine, and BETAPOWER®—to fuel proven results and performance^▪*. 
  • Increase Mass With 40% Fewer Sets: Delivers 50g of protein, including naturally occurring EAAs, plus carbs, and healthy fats—and it’s clinically proven to help get better results out of workouts▪*. 
  • Improve Muscle Strength In As Early As 2 Weeks: MyoTOR is clinically proven to accelerate improvements in strength with as little as 2 weeks of training and included in every serving of Mass XXX mass gainer•*. 
  • Improve Stamina: Take resistance training to a new limit with MyoTOR’s clinically studied support for improved muscle endurance and BETAPOWER’s athletic performance benefits•*. 
  • Third-Party Tested: Trusted by athletes around the world, our formula features a completely transparent label and is third-party tested for banned substances and protein content⬩.
  • Gluten free, no artificial colors

 

 ■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. 

•2 clinical studies have examined MyoTOR® for increasing muscle strength and endurance. In both 8-week studies, subjects participated in resistance training programs or voluntary exercise and consumed MyoTOR® or a placebo. The MyoTOR® groups showed significant increases in upper- and lower-body strength and muscle endurance compared to those who took a placebo. 

⬩Informed Choice products are subject to a rigorous Anti-Doping program that includes protocols for testing & monitoring for over 285 compounds.

Serving Size  About Four Scoops (206 g)
Servings Per Container  13

Amount Per Serving      % DV 

Calories 770  

Total Fat 6g   8%+
 Saturated Fat 4g   20%+
Cholesterol 100mg   33%+
Total Carbohydrate 127g   46%+
 Total Sugars 8g    
 Includes 5 g Added Sugars 5g   10%+
Protein 50g   100%
Calcium 450mg    35%
Sodium 490mg   21% 
Potassium 220mg    5%
Creatine Monohydrate 3g    
Betaine Anhydrous (as BetaPower®) 2.5g    
MyoTOR® (Sphaeranthus indicus Flower Head Extract, Mangifera indica Bark Extract) 650mg    
Creatine Precursor Blend 500mg    
 L-Arginine 240mg    
 Glycine 240mg    
 L-Methionine 20mg    

 

Serving Size

4

Servings Per Container

13

Other Ingredients

Maltodextrin, Whey Protein Concentrate, Micellar Casein, Milk Protein Isolate, Medium Chain Triglycerides, Natural & Artificial Flavor, Salt, Gum Blend (Guar Gum, Acacia Gum, Xanthan Gum), Sunflower Lecithin, Sucralose, Silicon Dioxide, Shellac, Citric Acid.

Allergen Warnings

Contains Milk

Directions

As a dietary supplement, mix 4 scoops with 16 fl. oz. of cold water or your favorite beverage. On training days, consume post-workout. On non-training days, consume first thing in the morning or between meals.

Warnings

Consult your physician prior to using this product if you are pregnant, nursing, taking medication, or have a medical condition. Discontinue use two weeks prior to surgery. notice: Use this product as a food supplement only. Do not use for weight reduction. Product is sold by weight, not volume. Significant product settling may occur. Keep out of reach of children.

Warning: Cancer and Reproductive Harm-www.P65Warnings.ca.gov. 

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.

Storage

Store in a cool, dry place.

Licensing

Distributed by:
GNC Holdings, LLC
Pittsburgh, PA 15222

BetaPower® is a trademark of IFF or its affiliates.
MyoTOR® is a registered trademark of PLT Health Solutions and Laila Nutraceuticals, LLC US Patent #9,907,825 and international patents pending.

Note: This product cannot be shipped to Canada , Japan , Singapore
Shipping Methods And Costs

At checkout, you will be prompted to choose a shipping method for your item(s). Shipping costs are dependent on the items in your order and the shipping method you select. Your total shipping charges will automatically compute during checkout prior to the completion of your order.

If you are shipping within the United States, you will have the option of upgrading your shipping method for faster delivery (Standard, Expedited or Overnight). If you choose to upgrade your shipping method, your order must be received and clear credit authorization by 4:00 p.m. EST or your order may not be processed until the following business day. Business days are Monday-Friday, excluding observed holidays within the United States.

Shipping Rules and Restrictions
  • Orders are shipped on business days only. Business days are Monday-Friday, excluding observed holidays within the United States.
  • You will not be charged for any item until it is shipped to you.
  • Please call a Customer Service Specialist at 1-877-GNC-4700 if you have any questions.
30 Day Money-Back Guarantee

We want you to be fully satisfied with every item that you purchase from www.gnc.com or from an Authorized GNC Retailer. If you are not satisfied with an item that you have purchased, you may return the item within 30 days from the order date for a full refund of the purchase price, minus the shipping, handling, gift wrap, or other charges.

The item must be returned, unused or used, in good condition, in original boxes (whenever possible), and with all paperwork and accessories to ensure full credit.

Our Standard Return policies do not apply to all items. For a list of exceptions to our Standard Return policies click here.

Nutritional Foundation
Calories – Four scoops provide 780+ calories when mixed with water.
Carbohydrates – 127g of carbohydrates fuel energy utilization during training and replace glycogen stores post-exercise. Carbohydrates also prevents the body from using protein as energy.
Protein – 50 grams of fast, medium, and slow-digesting protein per serving, providing fuel for working muscle, recovery, and maximum gains^*.
Power Plus Blend
Betaine – BETAPOWER®, a patented betaine anhydrous, clinically dosed to support power and enhance athletic performance*.
Creatine Blend – Creatine monohydrate and micronized creatine monohydrate join forces to fuel high intensity exercise and support muscle protein synthesis*.
MyoTOR® - An herbal blend of Sphaeranthus indicus Flower Head Extract and Mangifera indica Bark Extract, clinically protein to improve muscle strength with half the exercise in as early as 2 weeks●♦*
Creatine Precursor – This amino blend includes L-Arginine, L-Glycine, and Micronized L-Methionine, 3 precursors essential for creatinine synthesis.
Micronized Amino Acids
Micronized L-Glutamine - Glutamine, one of the most abundant amino acids found in muscles, is involved in protein synthesis. Intense exercise can contribute to the depletion of muscle glutamine stores by increasing the release of glutamine from muscle cells*.
Micronized L-Arginine – Arginine is a precursor for synthesizing nitric oxide, proteins, and creatine – key components for fueling performance and gaining mass^*
Micronized L-Leucine – An essential amino acid, Leucine is crucial to regulating muscle protein synthesis, fueling muscle cells, and supporting protein balance^*.
Great product. Highly recommend for gaining weight. Strawberry flavor has great taste.

-Shawn S. Verified Purchaser
OUTSTANDING PERFORMANCE AND TASTE!
"Absolutely love this stuff! I've tried many different protein powders, I can feel and see a difference in my size and performance before I was finished with my first tub. I'm about 8 tubs in, and have no plans of changing. Plus, the strawberry flavor is on point!"
-Walter F. Verified Purchaser
Benefits Through Bulking Season
What to expect taking Mass XXX
IMMEDIATELY
Nutritional assurance you're meeting your macro goals with 50g high-quality protein, 780+ nutrient-dense calories, up to 130g of carbohydrates, and healthy fats. A satisfying shake available in 4 delicious flavors to support your mass gaining and performance goals^*
2-6 Weeks
With clinically proven MyoTOR®, you can expect to see rapid performance results in as early as 2 weeks♦*. With a high calorie diet and appropriate strength training program, plus 1-2 servings of Mass XXX per day, the scale will start to move. Expect weight gain and muscle growth to the maXXX^*. With the Power Plus Blend and Micronized Amino Acids, you'll feel beneficial muscle fuel for exercise during intense training. Experience max performance with 40% fewer sets▪^*. Plus, when taken post workout, you'll notice improvements in muscle recovery. Feel confident your training is paying off.
3-4 Months & Beyond
The mass is on. You've met your gaining goals or are getting close! Consistency (and training) has paid off. You're feeling bigger, stronger, fitter, and ready to accomplish your next fitness challenge!
PERFORMANCE SUPPORT DOESN'T STOP HERE
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GNC PRODUCT SERIES: A DEEP DIVE INTO GNC AMP XXX
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Which Clinically Proven GNC AMP Protein
is Right for You

MASS GAINER

Mass Gainer

PERFORMANCE

Performance

THERMOGENIC

THERMOGENIC

NEUROSURGE

Neurosurge
BENEFIT
CLINICALLY PROVEN STRENGTH AND MASS GAINER^*
CLINICALLY PROVEN PERFORMANCE PROTEIN
CLINICALLY PROVEN PROTEIN + THERMOGENIC
CLINICALLY PROVEN PROTEIN + TEST & POWER
CALORIES
780-800
200
200
200
PROTEIN
50g
40g
40g
40g
FEATURED INGREDIENTS
BETAPOWER®
MyoTOR®
CREATINE
AMINO ACIDS
Velositol®
ENZYME BLEND
CAFFEINE
THERMOGENIC BLEND
TESTOFEN®

FAQs
Will I gain muscle mass using GNC AMP Mass XXX™?

GNC AMP Mass XXX™ was formulated and clinically proven to gain muscle mass, when combined with a resistance training program and adequate calorie intake. Meeting your daily calorie goals to add muscle mass can be challenging, which is why GNC AMP Mass XXX™ helps you meet higher calorie requirements. Plus it includes clinically studied ingredients to help enhance your bulking goals and improve performance. 

Can women use GNC AMP Mass XXX™?

Yes! While GNC AMP Mass XXX™ was clinically studied in men, the formula was designed to support muscle growth and performance gains for anyone looking to enhance their goals^*.

Should I use GNC AMP Mass XXX™ before or after a workout?

For best results, use 1-2 times daily. On training days, consume one serving post-workout. On non-training days, consume one serving first thing in the morning or between meals as needed. 

Do I have to workout while using this product?

This product was intended to help your muscles recover and grow from your exercise program. It also includes ingredients to improve performance benefits. So, yes! Exercise is a critical tool to combine with this product. However, you can consume GNC AMP Mass XXX™ on non-training days to meet your calorie goals.

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