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Get 20% off Weight Gainers with the code: GAIN *Only applicable for products from the Weight Gainer category. Not valid in combination with other promotions or bundles.


  • High-Protein Weight Gainer
  • 60 Grams of Protein Per Serving
  • 85 Grams of Carbohydrates Per Serving
  • No more than 4 Grams of Added Sugar
From $52.99 .

Product Overview

High-Protein Weight Gainer

Putting on size requires a balance of heavy training, adequate rest and quality nutrition. Because everyone's a little different, some have a harder time packing on muscle than others. PRO GAINER is a high-protein formula delivering calories that count during recovery. Each shake provides ample supplemental protein, carbs, vitamins and minerals to build on the amount you're getting through a balanced diet of food. 


  • 60 Grams of Protein Per Serving
  • 85 Grams of Carbohydrates Per Serving
  • 650 Calories Per Serving
  • 60:85 Protein To Carb Ratio
  • No more than 4 Grams of Added Sugars

Suggested Use

Just add one heaping scoop of Pro Complex Gainer to 16 fluid ounces of water, milk or your favorite beverage in a shaker cup. Then shake until thoroughly mixed. Use in combination with a healthy, balanced diet and exercise program.

For healthy adults, consume enough energy from a combination of high quality foods and supplements throughout the day as part of a balanced diet and exercise program.

Nutritional Information

Nutritional information will be shown when a flavour and/or size is selected.

Customer Reviews

Overall Rating (4.9)
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Awesome stuff!

Review by Jason M on Aug 8, 2021
Drink one serving in the morning and one at night, this stuff really works and I'm putting on the added weight I'm looking for. Tastes really good!

Good stuff

Review by Darian Ruiz on Jun 30, 2021
I love this stuff the gains are coming along, i love the flavor, wish they had more though.

Great protein

Review by DENNIS GREENWOOD on Jun 18, 2021
Great protein. Easy on my stomach.

Good Boost

Review by Wesley Johnson on Jun 2, 2021
Great morning calorie boost, vanilla tastes great, just ordered chocolate to try out. It has essential vitamins and nutrients which has let me cut back on my multivitamins. It also has helped me hit calorie goals which otherwise would be difficult to reach. Only downside is cost, at ~3$ a serving it adds up pretty quick. A 10 lb bag only has 28 servings so you are looking at a 10 lb bag a month or so.

Totally Underrated

Review by James Renna on May 25, 2021
Instead of a protein shake, I use a half serving of Pro Gainer, and the carbs make all the difference in the world in my opinion. Also, the saturated fat is low compared to other weight gainers.

Gains like a pro

Review by Michael Pardo on May 21, 2021
I've been using the pro gainer for a couple months now. I'm a hard gainer and it helped me gain a solid 10 pounds on top of my regular diet. I will say it is sweet but better than most shakes I've tried out.

ON'S Last Golden Egg Available!

Review by Justin.D on May 14, 2021
This is the best high Calorie shake under the title (Gainer) ever made and is the Last Golden Egg product formula that ON has to offer from the former glory days of the great company before the new people took it over and Soiled the quality. This is the last genuine original Formula and Nutritionally spec'd product of Optimum Nutrition standing.

Best lean muscle gainer out there

Review by Rick on May 4, 2021
This is the best lean muscle gainer out there. I struggled for the longest time finding the appropriate protein for the build I’m trying to obtain and maintain. Often times they have too many carbs. This was a perfect blend. I would highly recommend! All the flavors taste great too.

Love it

Review by FPF on May 4, 2021
Regardless if you’re trying to put on weight or not this protein is extremely effective. I’m 55 and putting on more muscle than I have in a long time. Tastes great as well.

Pro Gainer

Review by Bryce Premo on Apr 5, 2021
Very smooth taste! Easily mixed and not overwhelming after drinking. Doesn't make you feel bloated or too full! My favorite protein supplement to date.

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