Xtreme Size Up

Xtreme Size Up

Whey Protein Powder Contributing To Muscle Growth
Protein, Creatine, Glutamine, Calories And Carbs To Support and Maintain Muscle Mass
6.8  out of 10  (30 Reviews)

Product Overview

Size Up

MET-Rx Xtreme Size Up features FOUR Hardcore Optimizer Blends to help you keep growing.* Each serving of Xtreme Size-Up contains:

  • 600 Calories
  • 60g Protein
  • Over 70g of Energizing Carbs
  • 3g Creatine
  • 3g Glutamine
  • No Fructose
  • No Aspartame

Hard-gainers and mass-monsters unite! Your days of trying to take down endless amounts of food per sitting just to put on weight or maintain your weight are over! It’s time to grow and put on some quality mass.* Notice how we said “quality”? This isn’t your throw the kitchen sink in it type product where you will put on weight—sloppy weight. This is a very well thought out profile to fit your needs.

While this product is not meant to be used to replace whole food meals, it can be used as a meal supplement to increase your calories. Size-Up gainer mixes quickly and goes down easy.

You want to get big and put on some serious size this off-season? Then get yourself some MET-Rx Xtreme Size Up today, because if you aren’t, your competition is!*

Use in conjunction with an intense daily exercise program and a balanced diet including an adequate caloric intake.

Ratings & Reviews

Xtreme Size Up
Overall Rating
30 Ratings
Verified Buyer Rating
3 Ratings
Average Flavor Rating
2 Flavors
Top Rated Flavor
By clicking the button above, you agree to entering the Bodybuilding.com Reviews section. Products in the Store are not intended to diagnose, treat, cure, or prevent any disease.
Jul 10, 2019
Verified Buyer
  • 9 Vanilla

Too many 'Gum' additives; once mixed, my yummy vanilla shake quickly turns into pudding! Very thick and unappetizing! I really want to like this product for all the positive ingredients; So, MetRx if you are listening, please reinvent the wheel and remove the thickening agents from this product. Then, I'll be the first to purchase this gainer again. Thank you, John Thomason

Oct 29, 2015

Value: 6/10 Mixability: 8/10 Taste: 9/10 Pretty good overall. Make your own gainer though.

Nov 11, 2013
Verified Buyer
No written review.
Sep 16, 2013

Good shake, gets thick in just 12 oz, be sure to use more water.

Aug 28, 2013
  • 7 Chocolate

I just logged this product. My favorite thing about Size Up was the macros in it. Hefty amount of calories/carbs/protein per serving which really helps to hit your nutrition goals for the day. I had one shake a day and made some awesome concoctions. You can add in anything that you can imagine. The shake was very thick, that was the only downside to it.

Jul 07, 2013
  • 10 Vanilla
Jul 02, 2013
No written review.
Jul 02, 2013
  • 10 Chocolate
Jul 02, 2013
No written review.
Jul 02, 2013
  • 10 Chocolate
  • 10 Vanilla
Feb 18, 2013
  • 9 Chocolate

I just wanted to maintain my body weight and it helped me a lot. Although I gained 4 kg initially but after that I maintained with workout. Good one! It dissolves very fast.. awesome taste.

Aug 02, 2012
  • 9 Chocolate

Pros: -Fast and effective weight gain -Taste is unique -Excellent for hard gainers Cons: -Little overpriced

Jun 22, 2012
  • 10 Chocolate
  • 10 Vanilla
Jun 21, 2012
  • 9 Chocolate

its good tasting but way to thick with milk and it doesn't dissolve very well. yesterday was my first day taking it so ill post another review in about a week or 2 to show my progress

Jun 19, 2012
  • 10 Chocolate
  • 10 Vanilla
2 Sizes
6 Lbs.
Choose a Size
{{group.violatorText}} {{group.name}}
1 Flavor
Choose a Flavor
Flavor Rating: {{sku.flavorRating | flavorRating}}
Was:  {{vm.group.strikePriceDisplay}}
Price: $54.99  ($3.44 / Serving)
On Backorder
Flavor Rating: 6.0
Protein, Creatine, Glutamine, Calories And Carbs To Support and Maintain Muscle Mass

What's in MET-Rx Xtreme Size Up

6 Lbs. Chocolate
Serving Size 4 Scoops (167 grams)
Servings Per Container16
Amount Per Serving % Daily Value **
Calories 640       
Calories From Fat 80       
Total Fat 8 g 12%**
Saturated Fat 4 g 20%**
Cholesterol 60 mg 20%
Total Carbohydrate 81 g 27%**
Dietary Fiber 8 g 32%**
Sugars 7 g ***
Protein 54 g 108%**
Vitamin A (50% As Beta-Carotene) 4,500 IU 90%
Vitamin C 60 mg 100%
Vitamin D 240 IU 60%
Vitamin E 45 IU 150%
Vitamin K 40 mcg 50%
Thiamin .9 mg 60%
Riboflavin 1 mg 59%
Niacin 20 mg 100%
Vitamin B-6 1.2 mg 60%
Folic Acid 400 mcg 100%
Vitamin B-12 3 mcg 50%
Biotin 180 mcg 60%
Pantothenic Acid 4 mg 40%
Calcium 983 mg 98%
Iron 14 mg 78%
Phosphorus 1,050 mg 105%
Iodine 66 mcg 44%
Magnesium 85 mg 21%
Zinc 8 mg 53%
Selenium 28 mcg 40%
Copper .97 mg 49%
Manganese 1.8 mg 90%
Chromium 55 mcg 46%
Molybdenum 61 mcg 81%
Chloride 259 mg 8%
Sodium 430 mg 18%
Potassium 1,760 mg 50%
Creatine Monohydrate 3,000 mg ***
L-Glutamine 3,000 mg ***
**Percent Daily Values are based on a 2,000 calorie diet.
***Daily Value not established.
Energizing Carb Optimizer Blend (Maltodextrin, Rice Bran, Oat Fiber), Metamyosyn® Muscle Mass Optimizer Blend (Whey Protein Concentrate, Milk Protein Concentrate, Calcium Sodium Caseinate, Creatine Monohydrate, L-Glutamine, Dried Egg White), Cocoa (Processed With Alkali), Multivitamin Optimizer Blend (Dipotassium Phosphate, Calcium Lactate, Di-Calcium Phosphate, Potassium Citrate, Potassium Chloride, Beta Carotene, Tricalcium Phosphate, Ascorbic Acid, Dl-Alpha Tocopheryl Acetate, Ferrous Fumarate, Niacinamide, Zinc Oxide, Copper Gluconate, D-Calcium Pantothenate, Manganese Sulfate, Pyridoxine Hydrochloride, Vitamin A Palmitate, Thiamin Hydrochloride, Riboflavin, Chromium Picolinate, Folic Acid, Biotin, Sodium Molybdate, Potassium Iodide, Sodium Selenite, Phytonadione, Cholecalciferol, Cyanocobalamin), Natural And Artificial Flavors, Non-Dairy Creamer (Sunflower Oil, Maltodextrin, Sodium Caseinate, Mono- And Diglycerides, Tocopherols (added to protect favor), Calcium Phosphate), Lean Lipid Optimizer Blend (Medium Chain Triglycerides, Sunflower Oil, Flaxseed Powder), Cellulose Gum, Xanthan Gum, Guar Gum, Carrageenan, Sucralose, Salt, Sodium Citrate, Acesulfame Potassium, Gelatin.
Contains milk, egg and soy ingredients.

Directions For Xtreme Size Up: For adults, mix four (4) scoops (640 calories) (167g) to 16 ounces of cold water and mix thoroughly in a blender or shaker. For increased calories, use 16 ounces of skim milk (806 total calories) or 2% milk (884 total calories) instead of water. Increase or decrease the amount of liquid to achieve desired consistency. Drink immediately for best results. As a reminder, discuss the supplements and medications you take with your health care providers. 


Not intended for use by pregnant or nursing women. If you are taking any medications, planning any medical or surgical procedure or have any medical condition, consult your doctor before use. Avoid this product if you have kidney disease. Discontinue use and consult your doctor if any adverse reactions occur. Not intended for use by persons under the age of 18.


* 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.
Learn more about Whey Protein.
Check out other Performance Products.