Do Mass Gainers Work (Or Are You Wasting Your Money)

Mass gainers are one of the most popular supplements to hit the online and retail shelves in the last 20 years. Even in the UK, a local supermarket store will have a supplement section that consists of a 50/50 split of protein powders and mass gainers. 

While you frequently see mass gainers advertised with the promise of adding 10lbs-20lbs of lean muscle mass to your frame in record time this only further leads to the question of whether mass gainers actually work. 

This will largely depend on your view of what you consider to be the end result, mass gainers will certainly add ‘mass’ to your frame but will they help you add plenty of lean muscle mass…

Do mass gainers work? Mass gainers work in the sense that you will gain weight when supplementing with them however, mass gainers are not an optimal supplement if your goal is to build lean muscle mass. Most mass gainers will result in you gaining water weight and body fat but little muscle mass in comparison. 

In this article I’m going to run over mass gainers in a bit more details but the key takeaway will be that if you want to improve your physique at an optimal rate (building muscle while minimizing additional fat gain) then mass gainers are not a good supplement and simply do not work in helping you to achieve this. 

What Is a Mass Gainer

A mass gainer is a high calorie protein supplement with the intention of assisting you with weight/mass gain. The marketing for a mass gainer would give the impression that the purpose is to build muscle (which is true) but mass also includes water weight and unfortunately body fat. 

The high calorie shake is used to increase your daily caloric intake in order to supplement your training and ultimately help with muscle growth. A mass gainer is therefore typically used during a bulking or off season phase for body composition. 

Therefore when you are first looking into whether you want to supplement with a mass gainer, you need to understand that they can aid muscle growth however the scale weight moving up does not necessarily mean that you are piling on pounds of lean muscle tissue. 

The reason for this is that unlike protein powder, a mass gainer will have protein as an active ingredient but will then also include a fast acting carb source and even some fats and it’s this content that pushes up the total calorie content.

It’s typically the carbohydrate source that contributes most to the calorie content. I need to first say that I’m not against carb supplementation and frequently take either dextrose or maltodextrin (fast absorbing carbs). I take these intra and post workout to replenish muscle glycogen stores that get depleted with muscle contractions from weight training. 

The point to note is that the period around the training window is when your body is most primed to utilize carbs which means storing them as muscle glycogen and not body fat. A range of factors influence this so I’m not saying you should only consume carbs around your workout to build nothing but muscle. 

The point I want to make is that carbs are not a bad thing when it comes to building muscle however, the carb quantities in a mass gainer are significant! Most mass gainers will provide 1000kcals+ per serving of which only 80kcals-160kcals will come from protein (typical serving size providing 20g-40g protein. 

To sum up a mass gainer, they are high calorie shakes that have a very high carbohydrate content. The purpose is to build mass but don’t let the marketing hype distract you, the weight you gain from a mass gainer will be very limited in terms of muscle mass. 

Do Mass Gainers Work

When it comes to the question of “do mass gainers work” then there are two really straight forward answers depending on the person’s goal.

If you want to gain weight, I’m not talking strictly muscle here but purely you focus is on making the scale go up regardless of the outcome of the weight gain then yes mass gainers are a great way to help you do this. 

The high calorie content per serving will make it very easy to up your daily caloric intake, put you into a calorie surplus (alongside whole food meals) and you will gain weight/mass. 

The people that mass gainers are marketed to and those that are using them for a specific goal however, want to build muscle mass and put on size that is predominantly from muscle. Now when the question of whether mass gainers work or not then the answer becomes no. 

This is a very straightforward answer in my opinion and as a certified nutritionist and a stereotypical ‘hardgainer’ (naturally skinny, fast metabolism, finds it hard to gain weight and muscle mass) I feel very confident standing by this. 

Building muscle or losing body fat is a very simple equation despite what people might think, if you consume a calorie surplus (more calories in than what you expend in energy) then you will gain weight. The higher the surplus, the less you can utilize the calories in the short term and the more you will store in terms of adipose tissue and body fat. 

A surplus of 300kcal-500kcal per day is more than enough to support muscle growth for the majority of people, even the doomed hardgainers that these products are marketed to. The recommendations are usually 2-3 servings per day at 1000kcal per serving which amounts to 3000kcals per day before you even factor in your food. 

I weigh 180lbs at around 12% body fat year round and to maintain my muscle mass and weight my maintenance calories are almost 3,000kcals. For reference that means that taking the recommended serving suggestions for most mass gainers would see me reach my daily calorie limit before I even factor in any meals. 

As soon as you add your typical meals on top of this then it’s easy to see why mass gainers will not work for your intended purposes. Most beginners can build at most 0.5lbs of lean muscle mass per week at an optimal rate. 

The further along you are in training years the more this diminishes until you are looking at 0.5lbs being optimal over a few months of training! 

These are basic guidelines for an unassisted/natural lifter and while you will always see anomalies and exceptions to the average, the fact that you are considering needing a mass gainer in the first place will mean that you are unlikely to be gifted in the genetics and muscle building department!

Therefore the more calories you consume the more likely you are to gain additional body fat and not muscle mass. This is the part that most marketing ploys won’t show, if you see mass gainers claim to add 30lb of muscle mass to your frame in a specific time period then that is a clear sign to avoid the product. 

Are Mass Gainers Necessary

When people look to use mass gainers it’s usually for some very specific reasons, two of the most common reasons are:

  • They are struggling to consume enough calories each day from wholefood sources (lack of appetite, lack of time to cook, lack of money if a student).
  • They can’t gain weight even when they feel they are eating enough. If the scale isn’t moving at all then regardless of how slow the muscle building process is you still need it to increase in the long run. 

In both cases however, these issues or stumbling blocks are easily overcome without the use of mass gainers. Mass gainers are certainly not necessary and they do not solve the above issues as easily as the product description would have you believe. 

Struggling to consume enough calories can be a real issue and I’ve put together a guide here on bulking with a low appetite. One of the key points that I make is how you can use homemade mass gainer shakers to increase your calorie intake. 

What makes these different from typical mass gainers? The key difference is the macronutrient ratios in a mass gainer supplement. A good bulking macronutrient ratio could be 45% carbs, 35% protein and 20% fats for a typical hardgainer. 

This split is very easy to make with a balance wholefood diet however a mass gainer shake is typically in the region of 85% carbs, 10% protein and 5% fat**

If your daily macro split is that low in terms of protein intake and that high in terms of fat intake then the chances are extremely high that you will be putting on body fat at an accelerated pace. 

With a homemade shake you can adjust the macro intake accordingly bringing up both the protein and fat intake whilst lowering the carb intake. A higher carb intake is important to fuel your workouts, replenish glycogen stores and support muscle growth. 

The incredibly high carb quantities of a mass gainer supplement mean that you might increase your calorie intake but it won’t give you the desired result that you are looking for and therefore I’d say that they are far from necessary.

** This figure is an average and does not relate to a specific brand.

Do Mass Gainers Have Side Effects

I’ve been making the same point throughout this article which is that a mass gainer has a lower protein content than what you might expect whilst being significantly higher in carbs, the combination of which is likely to lead to gaining more water and fat mass. 

I feel as though I’ve ranted quite a bit rather than giving a precise summary and therefore I’m going to use a quote from Medical News Today to summarize the main side effect from supplementing with mass gainers:

“If a person consumes mass gainer supplements without working out regularly, they are likely to gain fat rather than muscle. Some people may, therefore, benefit more from increasing the amount of lean protein in their diet instead.”

This is a statement aimed at the general public and average gym goer, if you are reading this article however then you are likely more focused on improving body composition and therefore I’ll expand on this comment slightly. 

Even if you are working out regularly, the calorie content of a mass gainer is so high that you are still not going to utilize the surplus calories enough to prevent the excess fat gain. A higher protein intake is shown to have a direct correlation with increased muscle mass and lower body fat (source). 

I recently produced an article comparing mass gainers vs whey protein for skinny guys which you can find here and the summary is basically use whey protein to increase daily protein intake and forget about the hardgainers. 

Fat gain is only one side effect when it comes to supplementing with mass gainers though, it’s likely that you will experience at least one of the following when consuming such a high calorie shake that for most companies will be made with low quality ingredients in order to maintain profit margins:

  • Bloating
  • Increased bowel movements (almost guaranteed)
  • Increased thirst
  • Stomach cramping (due to digestion)
  • Reduced appetite (not ideal when bulking)


If I’m being honest the side effects are not drastic and some of these will occur naturally when increasing your calorie consumption, the main issue is of course the fat gain which can be controlled when increasing calories through whole food sources but not so easily when a mass gainer has such a poor macronutrient ratio!

Do Mass Gainers Increase Belly Fat

This ties in with the above side effects of supplementing with mass gainers but it’s worth saying that for most males (females store body fat differently) you are likely to see an increase in belly fat when supplementing with mass gainers. 

The reason for this is that the majority of males tend to store the most body fat in their midsections which means the abdomen, hips and lower back. While you might think you are immune to this as a hardgainer or feel as though you have a lightning fast metabolism to prevent it the truth is that the high calorie content of most mass gainers need to be stored somewhere. 

A small calorie surplus is manageable for most people however as soon as you start having a calorie surplus of >1000kcals then it becomes increasingly more likely that you will start to gain excess body fat at an accelerated rate.

Humans typically don’t have a direct choice on how their body best utilizes nutrients, some people can eat junk food and still build nothing but muscle while others only need to look at cake and they go up a jean size. 

While we have some indirect actions that we can do to influence nutrient partitioning like carb cycling, weight training, intensive cardio, intermittent fasting and many more things these are only influences at a smaller calorie consumption. 

As soon as you go too high in a surplus then these start to lose any significance as you will be simply consuming too many calories than your body can optimally utilize. The exception of course is for those that take a performance enhancing substance but I don’t get into the specifics of that. 

Therefore if you are consuming a high calorie surplus due to the large calorie intake that comes with supplementing with mass gainers then it’s likely you will start to gain fat around your belly and midsection as a whole. 

Does a Mass Gainer Work for Skinny Guys

The person most likely to be convinced by mass gaining supplements and be enticed into purchasing them is a skinny ectomorph/hardgainer. 

These are the people with long limbs, little muscle mass, small bones/joints, a fast metabolism and a higher percentage of slow twitch muscle fibres which are more suited to endurance based, cardiovascular activity. All of these treats are not ideal for building muscle mass or size in general. 

I know this because I’m a typical hardgainer and I don’t point that out to “understand the struggles” because I know first hand that if you get stronger in basic lifts over weeks, months and years whilst also having your diet and recovery in place then you will build pounds and pounds of muscle. 

Looking for a shortcut and falling for some false marketing promises is not the route to take and this is why people struggle for results, even if you are a skinny guy. 

A mass gainer will work for a skinny game in the same way that it will work for an average or overweight guy in that it certainly contributes to you gaining mass however, as with my point earlier this will not be mostly muscle mass and will likely be fat mass. 

Just because you are naturally skinny and have a fast metabolism does not make you an exception when it comes to physique development. A drastic calorie deficit will see you lose scale weight but the opposite is true in that you will lose some body fat but also water weight and muscle mass. 

Any time you put your body through an extreme you are likely to see a result that is in line with what you are aiming for but the unfortunate truth with mass gainers is that mass does not necessarily mean muscle and this is where most people will damage the progress in terms of their physique.

What Next

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