Optimum Nutrition Pro Gainer Review (Is this Mass Gainer Any Good?)

Optimum Nutrition Pro Gainer Review 2022 – Pros, Cons, Pricing, and Alternatives

Best for: Post-Workout Lean Gains

Overall rating

4.2 out of 5.0 stars

The Optimum Nutrition Pro Gainer delivers 650 calories per 1 heaping scoop or 165g of powder.

It provides you 60g of quick-digesting amino acids from proteins and peptides, 85g of rapid-absorbing carbs, and 8g of fats from good sources.

This supplement also has an added 22g of vitamins and minerals. So, it is not only a great macronutrient source but augments your micronutrient intake as well.

Later, we’ll be looking at the Optimum Nutrition Pro Gainer in-depth. But to start, here’s a quick glance at this mass gainer:

Nutrition profileProtein contentFlavorPricing
4.5 out of 5.0 stars4.5 out of 5.0 stars4.0 out of 5.0 stars4.0 out of 5.0 stars
Rapid absorption of macronutrients❌ Limited flavor options
✅ High protein content❌ Can be pricey
✅ Great taste

This Optimum Nutrition Pro Gainer review is all about the good, the bad, and the okay parts of the mass gainer.

What you would be getting is a detailed look of the following:

  • Nutrition profile
  • Macro make-up
  • Protein content and sources
  • Flavor
  • Pricing

I also shared my experience using the Optimum Nutrition Pro Gainer. 

Do you think I got more gains or just maintained my build?

Stick around to find out at the end of this Optimum Nutrition Pro Gainer review. You’ll discover if this popular bodybuilding supplement brand’s mass gainer is the right choice for you.

Product Overview

Before I get deep into my review, let me take you through a quick peek of the most important features of the Optimum Nutrition Pro Gainer.

This mass gainer packs 60 grams of protein and 85 grams of carbohydrates that are digested fast, making it a great post-workout supplement. 

It also contains 8 grams of fats from healthy sources.

These macros give you a total of 650 calories in one serving. That’s enough to replenish your energy and protein stores, and kickstart recovery.

Optimum Nutrition Pro Gainer is also packed with added vitamins and minerals. They help your body be at an ideal state to build muscle mass.

Gaining mass was always a struggle for me…

Some jacked dudes advised going into a dirty bulk.

 “Just gain as much weight as you can for a few months, then go on a diet and burn the fat off,” they said.

The clean bulkers would say, “Calculate your baseline caloric needs, then go over that by 300-500 calories. You’ll be lean all the time and still gain muscle.” 

So who do you think I followed?

You guessed right. I went with the second piece of advice. 

But I knew I needed a supplement because I hated eating more than usual. 

“There must be an easier way to do this,” I mumbled while the strip of chicken breast was hanging from my mouth.

This is when I found the Optimum Nutrition Pro Gainer at my local supplement store.

I did not have to feel bloated all the time. I did not dread the next meal of bland and dry meat and rice. I had the 650 calories I needed for a surplus in my shaker cup. 

It was like love at first scoop!

My muscles after a few months. I felt stronger and looked better in the mirror – no fat and no regrets.

Clean bulking was a good choice, and Optimum Nutrition Pro Gainer made it easier for me to gain.

Does the “before” me remind you of the “now” you? Then keep reading, brah. (Zyzz, anyone?)

If you are:

  • Looking to build muscle mass yet keep your body fat low
  • Looking for a great post-workout or early morning supplement
  • Someone who easily gains weight, even worse, fat

Then Optimum Nutrition Pro Gainer might be your perfect match.

However, if you are looking for a mass gainer with high calories and macronutrients to cure your hard-gainer woes, then you’d probably be better off with MuscleTech Mass-TechExtreme 2000. It has 2,050 calories from 440g of carbs, 60g of protein, and 6g of fats per serving.

Here’s My Thoughts and Opinions On the Optimum Nutrition Pro Gainer

Nutrition Profile

Optimum Nutrition Pro Gainer delivers quick-absorbing macronutrients. 

The carbohydrates all come from maltodextrin, a high-GI carb that means it’s rapidly absorbed by the body upon ingestion.

Although insulin-spiking, 85g of carbs per serving shouldn’t scare you because this amount can easily be used in a workout or stored in the muscles as glycogen after your sweat sesh.

The medium-chain triglycerides are the most significant bit in this mass gainer’s fat content. 

They are a popular immediate source of energy. Since they digest and provide energy quickly, you don’t have to worry much about getting flabby around your waist.

The proteins utilized in this supplement are from fast-digesting sources, too. I’ll explain this a bit more later on.

Overall, the “fast” characteristics of its nutrients make Optimum Nutrition Pro Gainer an awesome pre-workout supplement to fuel your training sessions. 

It’s also a great post-workout drink to kick-start muscle recovery and growth.


I highly recommend the Optimum Nutrition Pro Gainer for a quick and easy dose of nutrients around your workout sessions and upon waking up. 

Protein Content

Picking up on the topic of protein, the protein sources in Pro Gainer come mostly from whey –the most popular quick-absorbing protein — and protein peptides that are absorbed even faster than whey.

Hence, this supplement is sure to kickstart muscle protein synthesis after ingestion, especially after a brutal training sesh. 

Remember, the more time you spend recovering from a bout of resistance training, the more positive adaptations, or muscle growth, occurs.


At 60 grams of protein per serving, the Pro Gainer delivers more of the most important muscle-building nutrient when compared to other mass gainers in the 500-700 calories-per-serving range.


This mass gainer tastes great. 

For those used to the usual bland or metallic tastes of most protein and mass gainer powders, you are either in for a treat or a surprise.

The flavors can taste too sweet, especially double chocolate. Personally, I like that it tastes exactly like a chocolate milkshake but minus the empty calories.

However, you’d want to add more water than suggested as it can come out too thick and foamy, especially if you use an electric blender.


The flavor won’t be an issue with the Pro Gainer. You can choose between Vanilla Custard and Double Chocolate, and I can almost guarantee that you’d love the taste.
This clean gainer will help you satisfy your sweet tooth without breaking your diet.


At a little above $3 per serving for their 10-lb bag, this mass gainer is on the expensive side. 

But, given that it comes from one of the best supplement brands and has 650 calories per serving, I think that’s a fair price.

Also, a 10lb bag can last more than 28 servings. 

It’s slightly an issue to me because as it turns out I wasn’t getting the serving size I thought I was getting. 

One heaping scoop is 165g according to the label. But when I measured the biggest scoop I could get, it was only 130g based on my measuring scale.

If you opt for this mass gainer, make sure you are measuring 165g so you actually get the number of nutrients you are paying for in every scoop.


Go for Optimum NutritionPro Gainer if you have the budget for it. With the fast-acting nutrients, delectable flavors, plus the added vitamins and minerals, you’re getting good value for your money.

Check Out My Results From Using “Optimum Nutrition Pro Gainer”

From slightly fat to fit, the Pro Gainer helped me clean bulk my way to being jacked.

I used this supplement when I wanted to gain muscle but shed the fat I gained after a bad bulk.

I tried building muscle and losing fat at the same time, but it wasn’t as easy as I thought it would be. So I had to switch up my plan.

I  added Optimum Nutrition Pro Gainer to my well-calculated diet plan. And, it worked!

I knew I was on the right track when people thought I was on a cut for a competition or a photoshoot, when in reality I was gaining lean mass.

 Let’s take a look at what some users have to say about the ON Pro Gainer on Amazon:

“Optimum Nutrition Pro Gainer is one of my favorites. I recommend getting the vanilla flavor since it tastes good by itself and it is easily mixed with other things to change the flavor. I like to add cinnamon to my protein shakes and it tastes so good. It is also packed full of vitamins and minerals that your body needs. It is really an all-in-one bundle with plenty of protein, carbs, fats, vitamins, and minerals.”

“The scoop provided isn’t anywhere close to the stated 165 grams that make one serving. I tried scooping up as much as I could but no matter how many times I tried, I could only get to 120 grams. It would make more sense if they provided a scooper that provided 82.5 grams and just change the label to read Serving Size: 2 scoops. I was going to rate the product 5 stars but I had to subtract a star because of the scooper size. Despite all these facts, it does taste great and mixes well.”

“I’ve been weightlifting for about 5 years off and on. My biggest struggle has always been accumulating mass. I consistently stay around 5-10% BF, and need to eat AT LEAST 4,000 calories per day to gain muscle mass (a downfall of being 6’3″). I’ve been making these shakes in my Ninja blender and they have come out wonderfully. I use 8 ounces of milk and 8 ounces of water and 1.5 scoops of protein per shake. It ends up being about 800 calories and 65-70 grams of protein. I drink one in the morning after my workout and one at night before bed. I’ve gained about 3-4lbs when I was using the first bag. Will continue to buy! Would recommend!”

Is the Optimum Nutrition Pro Gainer Right For You?

Now, this is the part of my Optimum Nutrition Pro Gainer review where I want to put YOU in the spotlight. Do you think this is the right mass gainer for you?

The Pro Gainer is not going to be the right choice for everyone, the same goes with any other mass gainer. So, I would like to specify who the ON Pro Gainer is going to be best for.

For the detail-oriented clean bulker:

Are you the type who likes to get down on the nitty-gritty of your nutrition and has a specific goal for your physique? High five, buddy!

You have to pay close attention to everything that will affect how you lift and how you look if you want to achieve significant changes immediately.

Optimum Nutrition Pro Gainer calories is just at 650, making it easy to incorporate into a strict diet and just enough to push you 300-500 calories over your caloric maintenance. 

Optimum Nutrition Pro Gainer nutritional content also includes other nutrient sources and additives, which makes it great for building muscle mass and achieving overall health.

Clean bulking requires a lot of planning and calculating. It’s not easy, but I’ve been there and trust me when I say it’s the best route to take for your mass gaining journey.

For the busy and time-constrained gym enthusiast:

Sometimes, it’s hard to squeeze a gym session into a tight schedule, or even spend time preparing healthy, well-portioned meals. 

If you’re always on the run and do not have much time for meal preps, Optimum Nutrition Pro Gainer will be a great addition to your nutrition.

The Pro Gainer is a quick and easy way to improve your overall health and keep up with your lifestyle.


If you need a significant amount of calories to reach your physique goals, maybe you really need a meal replacement. Take a look at Naked Mass – Natural Weight Gainer. It has 1250 calories per serving with 50g of protein, 252g of carbohydrates, and just 2.5g of fats.

Final Thoughts

To conclude, the Optimum Nutrition Pro Gainer deserves to be a staple in your pre and post-workout nutrition. Its fast-acting ingredients will be utilized best during these times.

At 650 calories per scoop, I think it is best for people who are strict with their nutrition. 

About $4 for a serving of just 650 calories could be a waste for hard gainers, given how many other mass gainers are out there with double to triple Optimum Nutrition Pro Gainer calories.

This mass gainer is for those that do not need to go to extremes just to gain weight. It is for experienced (hence, the “pro” in Pro Gainer) lifters that know how to tinker with their diet in a way that will best suit their goals. 

Optimum Nutrition Pro Gainer Weight Gainer Protein Powder,Vitamin C and Zinc for Immune Support, Double Rich Chocolate, 10.19 Pounds (Packaging May Vary)
  • Vitamin C and Zinc Provides Immune Support along with Vitamin E
  • 650 CALORIES - delivering calories that count to support your gains
  • 60G PROTEIN BLEND - support your mass gaining goals with high-quality protein
  • 85G CARBOHYDRATES - help restore energy levels
  • 7g SUGAR (OR LESS)


What does Pro Gainer do?

The Pro Gainer helps you easily add 650 calories to your overall daily caloric intake to help you gain muscle mass.

When is the best time to take the Optimum Nutrition Pro Gainer?

Given its fast-absorbing ingredients, it is best to take it before a workout to fuel your body with 85g of carbs or post-workout to immediately kickstart muscle protein synthesis with its 60g of fast-absorbing proteins.

Is the Optimum Nutrition Pro Gainer a weight gainer or protein powder?

The Pro Gainer is advertised as a mass gainer. However, it is a protein supplement at the same time since it provides you with 60g of protein for every serving.

What is the best flavor of the ON Pro Gainer?

According to reviews and my personal experience, Double Chocolate is the best-tasting between the two flavors.

How many servings does the Optimum Nutrition Pro Gainer have?

The 10-pound bag of Pro Gainer can give you up to 28 servings per bag, at 165g each per serving. For the 5-pound one, you can have up to 14 servings per tub.

Imad Deryan

My name is Imad, and I struggled to gain mass in the past due to my metabolism and being very skinny. In this blog, I share the best reviews and advice when it comes to gaining weight and mass, for all the people that are struggling like I was.

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