As you begin your muscle building journey, in your quest to make progress as quickly as possible, you may come across something called a ‘weight gainer’.
These, as their name suggests, are designed to help you gain weight by providing you with a higher calorie intake.
Weight gainers can range anywhere from 250 calories all the way up to 1000 calories or more. If you’re someone who struggles to take in enough calories, this might seem like the perfection solution.
But is it?
In this review, let’s go over some of the need-to-know facts about weight gainers so that you can make an informed buying decision that's right for you.
The 5 Best Weight Gainers
Let’s give you a brief review of some of the best mass gainers you have to choose from.
#1 ON: Pro Gainer
#2 OPTIMUM NUTRITION Serious Mass
#3 BSN: True-Mass
#4 CystoSport CytoGainer
#5 MuscleMeds Carnivore Mass
1. Optimum Nutrition: Pro Gainer
Optimum Nutrition (ON) is a brand that many people know and trust, so it should come as no surprise that their mass gainer ranks up as our number one recommended product.
Pro Gainer will give you 650 calories per one scoop serving, 8 grams of dietary fat, 85 grams of carbs with 7 of those coming from sugar, and 60 grams of protein total.
This makes it a very balanced weight gainer that can be used at any point during the day. You’ll also take in 5 grams of dietary fiber, which will help give you maximum blood glucose control.
This product also contains a nice blend of whey, casein, as well as egg protein, so this will be a good option for those who tend to struggle with having too much whey in their diet plan.
The lactose content will naturally be lower thanks to the additions of casein and egg protein.
This product also contains medium chain triglycerides, which are a type of fat that serves as an excellent energy source in the body and can help with maintaining optimal body composition and prevent obesity, as noted by a study. 
2. OPTIMUM NUTRITION Serious Mass
Optimum Nutrition created another high-quality protein powder for those who want to gain weight.
Worried about how you can increase your caloric intake? Well, one serving of Serious Mass will give you 1,250 calories and 50 grams of protein. This supplement will provide you the nutrients needed to gain weight without forcing yourself to overeat.
It also speeds up muscle recovery after workout sessions to get you ready for the next gym day. Packed with 25 vitamins and minerals, Serious Mass keeps you energized while adding gains.
You can take this supplement between meals, during post-workout, or before going to bed.
Pro tip: If you wanna gain some serious size, mix this with whole milk.
3. BSN: True-Mass
BSN is well-known for their great tasting powders with their meal replacement product Syntha-6 being a bit hit for many.
Now, you can get the mass gainer version of Syntha-6 with True Mass.
This product contains 700 calories per 3-scoop serving and provides you with 17 grams of dietary fat, 90 grams of carbohydrates - 15 of those from sugar and 6 grams from fiber, as well as 50 grams of protein.
This is a higher fat product, so a great option later on in the day. Use it at a time other than the post-workout period.
It also contains 12 grams of BCAA’s, which studies suggest are powerful in supporting anabolism and muscle recovery in the body.
4. CystoSport CytoGainer
Cystosport is a name that’s been around for a while and is a company who makes protein powders as well as weight gainers. Their Cytogainer is a mass gainer that contains a lower overall calorie level at just 280 calories per two scoop serving.
Do keep in mind however that this product has two scoops per serving, whereas most products have 4, therefore you are taking less product per serving.
You’ll take in 2.5 grams of fat per serving, 37 grams of carbs, 5 of which are sugar, and 27 grams of protein.
It’s a good option for those who want something a little lighter and who are more concerned about body fat gain.
If you go with any one of these options as your weight gainer of choice, you can feel confident you are making an informed and wise decision.
Remember that with many of these, if the calorie content is a little too high for you but you trust the brand and like the flavors it comes in, you can simply opt to take fewer scoops per serving.
This will cut down the calorie count, making it more reasonable for your body.
5. MuscleMeds Carnivore Mass
If you are really watching your sugar and carb count in your quest for lean muscle mass, you’ll want to consider Carnivor Mass by MuscleMeds.
This protein powder is not made from whey, but instead, from beef, so is free of lactose and is overall, a very pure product.
With 0 grams of sugar, it’s one that will keep insulin levels stable, preventing unwanted body fat gain.
This one is also lighter in calories at 690 calories per serving, providing 50 grams of protein and 119 grams of carbs.
With only 3 grams of fat, it’s also one that’s a good choice following a workout session.
What Are Weight Gainers?
Weight gainers are a product designed to help you gain weight. 
Think supercharged protein powder, more or less.
The big difference is in the calorie and macronutrient count.
While the average protein powder contains around 100-130 calories per scoop, you’ll be looking at around 250-1000+ calories per serving when it comes to mass gainers.
The best weight gainers out on the market contain lower amounts of sugar, so that’s always something to be on the lookout for.
Weight gain powders are helpful for increasing calories when you can't increase your calories from food alone."
What to Look for in a Mass Gainer
1. Calorie requirements - Piling up calories must be challenging just by eating. As an alternative, you can opt for weight gainers to bulk up and meet your daily calorie requirements. Look for a meal replacement that can supply more than 450 calories in one serving to maximize your gains.
2. Quality protein (whey or casein) - One of the most important things to consider in finding the best mass gainer is the quality of protein used. Both whey and casein are considered as the best types of protein for muscle growth. The only difference between both is the rate of digestion where whey is more quickly absorbed by the body compared to casein.
3. Ingredients - Knowing how to read the food label gives an assurance that you get what you pay for. It also protects you from consuming ingredients that are not healthy for the body. Understanding the macronutrients (and micronutrients) on your favorite supplement is beneficial when planning your diet.
Which Weight Gainer Should I Drink?
Generally speaking, one serving of a weight gainer will be enough for most people. This will, however, depend on the calorie content of the drink and how fast your individual metabolism is.
What you should aim to do is match the weight gainer to your metabolic level. If you are a pure ectomorph and really struggling to gain weight, you’ll want to look for a product that has 500+ calories per serving.
If you are someone who is simply active, burning a lot of energy, but who can gain fat if they aren’t careful, then a weight gainer in the 250-400 calorie range is more appropriate.
Side Effects To Be Aware Of
Generally speaking, as weight gainer is quite similar to whey protein powder, you won’t be at risk for any extra symptoms over and beyond what you would with the standard protein powder.
Bloating and/or digestive issue - Some people may experience bloating and/or gas when using mass gainer, in part due to the lactose (if not having lactose free weight gainer), as well as simply due to the sheer calorie count.
To avoid this, consider working your way up. Try a mass gainer that has around 250-300 calories, then 450 calories, then the 600 calorie level and beyond..
Fat gain - Remember, your body can only build so much muscle at once. Any excess calories beyond this point will be converted into body fat. This is why more is not always better and why you shouldn’t go out and find the weight gainer with the highest calorie value thinking it will yield optimal results.
FAQ Before Buying
1. Who should Drink Weight Gainers?
While you can, you may notice you feel bloated and/or sluggish during the workout if you use the weight gainer prior to hitting the gym. For best results, try using it after the workout or at another point during the day.
2. Can I use a mass gainer before my workout session?
Weight gainers are for people that struggle to gain any weight, usually for people who are naturally thin and who have the ectomorph body type. Weight gainers may also be used by athletes who are expending a very high amount of energy on a day to day basis and need the extra calorie support.
A good rule of thumb is that if your daily calorie needs are higher than 3000 per day, looking into a weight gainer is a smart move. Eating more than 3000 calories per day from whole food sources can be hard to stomach, which is where the weight gainer comes in helpful.
3. Should I take my weight gainer with food?
While you can do this, do remember that weight gainers are very calorie dense and taking it with food may cause even more bloating to occur. Your best bet is to take it at a different time than when you are having your meal.
4. Can I take it on days I don't train in the gym?
You can if it helps you reach your calorie intake needs. Remember that your calorie intake may not be as high on non-training days, so adjust your intake accordingly.
You may decide to only take half the serving size on non-training days as an easy way to achieve better calorie control.
5. How and when can I take a mass gainer?
Weight gainers usually come in different flavors so you can directly mix them in water. If you want to add more calories, you can add milk. We highly recommend that you drink your mass gainer during breakfast, during post-workout, and before going to bed.
By doing this, you will achieve the best results as long as you workout and keep a healthy lifestyle.
The Best Mass Gainer?
The best mass gainers are those that don’t only help you gain weight -- they are also those that can give you the extra boost of energy from the calories they contain.
For folks who just need to keep their energy going, Optimum Nutrition Pro Gainer is the best choice not only in terms of increasing your energy, but also in terms of improving your overall nutrition.
It will pump you up to maximize your training results without worrying about “crashing” after your workout. This supplement is super-packed with protein, calories, vitamins, and minerals that are essential in your weight gain goals.
With its ability to restore energy levels and help with quicker recovery, we can say for certain that Optimum Nutrition Pro Gainer is one of the best mass gainers you can get your hands on.
Optimum Nutrition : Pro Gainer
Our #1 Weight Gainer Supplement
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2. Kleiner, Susan, & Greenwood-Robinson, Maggie, Get the Facts About Weight Gain Powders. Retrieved from https://us.humankinetics.com/blogs/excerpt/get-the-facts-about-weight-gain-powders
3. NHS Choices, How Can I Speed Up My Metabolism. Retrieved from https://www.nhs.uk/live-well/healthy-weight/metabolism-and-weight-loss/