5+ Mass Gainer Side Effects (THAT ARE DEADLY!)

January 9, 2024 |

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In this article, we’ll discuss both the general and specific side effects of different mass gainers that are deadly to your health.

Also, by the end of this read, you’ll be able to spot the ingredients that you need to avoid in your body-building powders.

Routinely restocking your kitchen cabinets with those bags of big calories and large macros apparently seems like a harmless mass-gaining deal. But if you look at the other side of things, gulping in those high carbs and high protein powders every day might be placing some consequences on your health.

Yes, mass gainers may commonly cause mild side effects such as an upset stomach or acne. However, in some cases, these side effects may be as serious as liver and kidney problems.

For instance, high glycemic carbs might increase your risk of developing diabetes.

In addition to this, a bunch of other stuff like artificial sugars and food additives like maltodextrin also contribute to mass gainer side effects like gastric distress and allergies.

So, keep reading to find out the details.

Is Mass Gainer Harmful? – 6 Nasty Side effects

No, as long as it has quality ingredients and the recommended macro split, mass gainers are good for consumption.

What is the preferred macro split, then? Most nutritionists have agreed upon a calorie split that has high carbohydrates, moderately high protein, and comparatively low fats for efficient lean muscle gain.

However, manufacturers mostly overstuff their powders with macronutrients, micronutrients, and certain filler ingredients to surpass their competitors and provide fast results, which may expose you to greater health risks.

And thus, here are some of the most commonly reported side effects of mass gainers that you need to look out for:

1. Unhealthy Weight Gain

All the extra macronutrients you consume are stored either as lean muscle or fat.

So, you can anticipate seeing your muscles swell up with mass gainers, but excessive calorie consumption and carbohydrates can also cause unhealthy weight gain at times.

According to Statista, as of 2021, about 20% of Americans consider carbohydrates as the prime culprit behind weight gain. In comparison, 22% of them believe that sugar is the main cause of their increasing weight. For 14% of the American population, calories sourced from fatty foods are what is increasing their pounds on the weight scale.

In contrast, only 4% of Americans thought that protein caused their weight gain.

And if you compare these stats and the composition of mass gainers, you will find that these powders are all about carbs, sugars, and calories.

Now, although carbohydrates are a great mass-gaining nutrient because the glycogen gets stored in the muscles causing them to grow, certain mass gainers have high glycemic carbohydrates like added sugars, maltodextrin, etc., which are hypothesized to cause fat accumulation in the body and put the individual at risk of unhealthy weight gain.

Moreover, the Harvard Medical School designed this large 5-year study which also concluded that glucose-stimulated insulin release in response to consuming high glycemic carbohydrates is ‘obesogenic.’

2. Gastrointestinal Problems

Gastrointestinal issues are the most commonly reported side effect of mass gainers because they contain allergens and high protein content.

Protein in mass gainers mostly occurs in the form of whey protein isolate, which may upset the stomach and cause bloating stomach pain, and other gastrointestinal symptoms.

Moreover, high protein consumption increases dehydration in the body, causing constipation and hard stools.

In addition to this, the fats in mass gainers are mostly derived from dairy sources, which makes them unsuitable for the lactose intolerant population as they may cause diarrhea and other symptoms.

Moreover, in most mass gainers, the carbohydrates grams mentioned on the product label are contributed by maltodextrin.

Maltodextrin is a common allergen because it is mostly sourced from wheat and may not be completely gluten-free. Thus, it may irritate the gut and cause inflammatory bowel syndrome, diarrhea, vomiting, flatulence, bloating, and other such symptoms.

3. Kidney Damage

Mass gainers may be suspected to cause kidney damage because they are high in protein and may also contain creatine, making them unsuitable for individuals with pre-existing kidney disease.

Most mass gainers contain creatine because it promotes muscle gain.

However, this review lists creatine as one of the supplements that may cause kidney dysfunction.

Moreover, the amino acids in protein have a high nitrogen content. Thus, due to excess protein consumption in the form of mass gainers, the kidneys have to work harder to remove the extra nitrogen and other waste products of protein metabolism.

Some user reports suggest that mass gainers may also cause kidney stones because they are mostly based on whey protein isolates.

For instance, a user shared on Reddit that he suspects that they got kidney stones after consuming whey protein shakes.

4. Liver Damage

Sometimes, mass gainers contain anabolic steroids, which are suspected of inducing liver damage.

Anabolic steroids mimic the male hormone testosterone, which helps to boost muscle gains. However, these synthetic molecules are slowly metabolized and cleared by the liver, which makes them hepatotoxic.

This 2019 study tested about 44 men taking body-building supplements, which revealed that these powders had induced liver injury in all of them.

Many of these men had elevated Aminotransferase levels, jaundice, mild hepatitis, and some additional symptoms linked to liver damage.

Surprisingly, manufacturers had not mentioned ‘steroids’ in the product labels of the supplements these men were taking.

5. Heart Disease

The three ingredients in mass gainers that increase your risk of cardiovascular disease are sugar content, sodium, saturated fats, and cholesterol.

Manufacturers add sugar to their mass gainers as a carbohydrate source.

Sugars also increase the calorie count of the powders and enhance their taste. But according to American Heart Association, these carbohydrates in the form of refined sugars such as sucrose are a major contributor to coronary heart disease in consumers.

Moreover, this 2017 review of multiple randomized control trials have reinstated the fact that added sugars increase the risk of cardiometabolic diseases. These studies showed that excessive consumption of sweeteners might cause high blood pressure, cardiovascular disease, and strokes.

Also, individuals who are pre-diagnosed with heart diseases should look out for the sodium, fat, and cholesterol content of mass gainers to prevent the worsening of symptoms.

6. Diabetes Risk

If there are high glycemic carbohydrates like sugars and maltodextrin in your mass gainers, they may reinforce the diabetes risk for you.

Research has shown that added sugars like sucralose and stevia disturb the gut microbiota, which may increase the risk of metabolic diseases like diabetes.

On the other hand, maltodextrin has a glycemic index even higher than sugar which may cause you to develop insulin resistance leading to diabetes.

Also read: 7 Best Mass Gainer Supplements Without Side Effects

Popular Mass Gainers and Their Side effects

In the above section, I made you aware of the general side effects of mass gainers. So, now in this section, I will address the specific risk of some of the most popular mass gainers available in stores and online.

mass gainer side effect table
Mass gainer brands’ side effects

So, head down to explain further without further delay:

Hyperbolic mass gainer side effects

Hyperbolic mass gainer might upset your gut, cause allergies, and damage your kidneys.

Users have complained that its thick composition, high-calorie count, and stodgy ingredients cause symptoms like stomach cramps, diarrhea, bloating, and gas.

These mass gainers may also increase the risk of the development of diabetes due to their high glycemic carbohydrates in them.

The beta-alanine in it may also cause a tingling sensation in the hands, feet, chest, and face, and common allergens like dairy and soy in it may cause inflammation.

Moreover, the high quantity of protein and amino acids in it may also increase your risk of kidney damage.

Serious mass gainer side effects

Many users on Amazon have reported various side effects of Optimum Nutrition Serious mass weight gainer caused due to its unhealthy composition might have a negative impact on the liver, gut, kidney, and other organs.

Stephan wrote an Amazon review in which he mentioned that he suspects that the ON serious mass gainer has more than 200 grams of maltodextrin in it.

He wrote that he used mass gainer for 3 days and remained passed out for most of the time and would wake up to sweet saliva in his mouth and felt like his mouth was foaming.

Stephen’s symptoms progressed to the development of a minor ulcer later on, after which he discontinued the product and noticed that his symptoms resolved within two days.

Jeremy, another user, wrote in his Amazon review that the serious mass gainer might cause liver damage. He wrote that after one week of using this mass gainer powder, he was diagnosed with mild fatty liver disease.

Moreover, Jeremy’s doctor had linked his condition to the greater than recommended values of vitamins and the many unhealthy ingredients in the mass gainer powder.

Eric Lobenstein wrote an Amazon review in which he mentioned getting kidney stones because of a serious mass gainer.

Other users have also reported symptoms of a sugar crash, lightheadedness, acne, hot flashes, stomach issues like gas, diarrhea, nausea, stomach pain, and fast heartbeat.

From what I can tell you from going over different reviews is that the serious mass gainer might not be suitable for you if you have diabetes, kidney disease, blood pressure, and heart problems.

Dymatize super mass gainer side effects

The Dymatize super mass gainer protein powder may impact your mood and cause digestive issues.

The users on the product’s website found this mass gainer super thick and concentrated, due to which it caused bloating, gas, and other gastrointestinal symptoms in them.

Moreover, most users in amazon reviews have reported depression as a major side effect of this product.

Many users have recommended against its use in case you have a history of depression.

The reason could be that the Dymatize mass gainer lacks the natural balance between Essential Amino Acids and Branched Chain Amino Acids, which may mess with your mood.

Anabolic mass gainer side effects

There are no specific side effects mentioned in user reviews for the Healthy N fit anabolic muscle gainer.

However, it has saturated fats, sodium, and cholesterol, which may negatively impact your heart health. Moreover, the high protein and amino acid-based formulation may also overburden the kidneys.

Mutant mass gainer side effects

The mutant mass gainer may cause digestive issues, allergies, or long-term side effects. An amazon user pointed out that it comes with caution of containing lead traces which pose a risk of cancer development.

According to various Amazon reviews, the mutant mass gainer may upset the stomach and cause explosive diarrhea, stomach pain, gas, and other gastrointestinal symptoms.

It also has a high glycemic carbohydrate (sucralose, maltodextrin), cholesterol, and saturated fats, increasing the risk of diabetes and heart issues.

It has several allergens like soy, milk, egg, and nuts, so it may also cause an allergic reaction.

Labrada mass gainer side effects

Labrada mass gainer also causes side effects similar to other mass gainers. It may cause digestive issues and increase the risk of diabetes and heart disease.

Many Amazon users have reported a lack of results and digestive problems like bloating, gas, diarrhea, abdominal pain, and cramps.

It has a high glycemic load due to the presence of maltodextrin and artificial sugars (sucralose, acesulfame potassium) that may reduce insulin sensitivity.

It also has saturated fats which are not good for heart health.

Carnivor mass gainer side effects

Carnivor mass gainers again pose risks to the heart and digestive health. Amazon critical reviews mostly complain of bloating, gas, diarrhea, stomach pain, and unhealthy weight gain.

It has a high sodium content that is not suitable for heart health.

It also has high carbohydrates that include maltodextrin, artificial sugars (sucralose, acesulfame potassium), and allergens that may upset the gut and cause metabolic disorders.

Muscletech mass gainer side effects

Muscletech mass gainers may also disturb the gut and pose long-term health risks. An anonymous Amazon user wrote that Muscletech’s mass gainer made them sick.

They reported dry mouth, foggy mind, and feeling similar to a panic attack on the first day. On the next day, they again had the first day’s symptoms, including gastrointestinal symptoms like gas and stomach cramps.

Many other users have also reported upset stomach especially bloating, as a common side effect of this mass gainer.

These mass gainers have high cholesterol, saturated fats, sodium, added sugars, and allergens, which may negatively impact your cardiometabolic health.

Muscleblaze mass gainer side effects

The macronutrients in the Muscleblaze mass gainer may cause generalized side effects.

According to user reviews, gastrointestinal symptoms like bloating, gas, diarrhea, and vomiting are the most common side effects. A user also reported high blood pressure and nosebleed. For one user, the side effects manifested as acne and hair loss.

Rule 1 mass gainer side effects

The basic concern related to Rule 1 mass gainer is its high sugar content, glycemic index, and allergens.

Most amazon users have also mentioned the sugar content and allergies in their reviews. This mass gainer is saturated with both natural and artificial sweeteners.

So, if you want to taste ultimate sweetness, you can give it a shot but beware of the risk of decreased insulin sensitivity that this bag of mass gainers carries. The allergens that may trigger a reaction are milk, soy, egg nuts, wheat, and fish.

Moreover, ingredients like saturated fat, sodium, and cholesterol might make this product unsuitable for individuals with blood pressure and heart problems.

Mass tech mass gainer side effects

The Mass tech mass gainer powder may irritate the stomach and cause allergies.

It may upset the stomach due to due to the high carbohydrate content, artificial sugars, and maltodextrin.

Moreover, it might not be suitable for everyone due to the presence of soy, eggs, nuts, shellfish, etc.

Massive mass gainer side effects

Ripped-up nutrition mass gainer is under-bought for now, so there are not many user reviews about it.

The ingredient profile doesn’t seem to have a very high macronutrient or micronutrient content that could pose a significant health risk.

However, since it contains sucralose and maltodextrin, you might want to look out for them.


Are mass gainers good for health?

Yes, quality mass gainers may help you achieve your mass gaining goals without causing health-threatening consequences.

However, these should not be consumed for a longer time.

Also, it is always better to consult an expert for their recommendation on the mass gainer that best suits your needs without triggering any underlying medical condition.

Should I take mass gainer every day?

Yes, you may take a mass gainer every day, even on rest days, to fulfill your daily calorie and macronutrient intake.

Does mass gainer cause liver damage?

Generally, no. But if your mass gainer contains steroids, then there’s a chance it could happen.

Most manufacturers secretly add steroids to their products and don’t mention them on the product labels, which ultimately affects the consumer’s liver. (which is why we always recommend buying from reputable companies)

Does mass gainer damage kidneys?

Yes, mass gainers with high protein content, especially animal-derived proteins, may damage kidneys.

However, the risk is greater for individuals with pre-existing kidney disease.

Can mass gainer cause heart problems?

Yes, mass gainers have a high quantity of sweeteners that are linked to causing strokes and other cardiovascular diseases.

Some mass gainers also have a high sodium content that may mess with your blood pressure and damage heart health.

Which mass gainer is best?

Some characteristics of the best mass gainers are that they would have an optimal macronutrient content, have low glycemic carbohydrates, do not have maltodextrin and filler ingredients, and most of all, do not cause digestive issues because that is the issue with most mass gainers.

And the Crazy Nutrition Mass gainer has all these features. It has clean carbohydrates that prevent sugar crashes and blood sugar spikes.

The high carb-to-protein ratio and low-fat content make this mass gainer ideal as it will maintain your energy levels, aid recovery, and work with protein to promote muscle formation. Moreover, the digestive enzymes and dietary fiber in it prevent stomach upset.


To conclude, consuming low-quality mass gainers and taking them over a considerable period may cause both acute and chronic side effects. These calorie-dense powders are most commonly affiliated with digestive issues and unhealthy weight gain.

Some mass gainers also have steroids, creatine, and maltodextrin, which may lead to long-term health complications like kidney and liver damage.

The added sugars in mass gainers have the potential to upset the gut microbiota and cause metabolic derangements, which may lead to weight gain, type 2 diabetes, and cardiovascular disease.

In a nutshell, processed micronutrient powders cannot replace whole foods, nor should they be consumed for the long term.

Moreover, these powders do not fulfill your micronutrient needs effectively, which may lead to mineral burnout.

Therefore, trying to fulfill your dietary needs with organic food should be your priority.

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