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Does Mass Gainer Make You Poop? (Can It Cause Diarrhea?)

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So, you’ve decided it’s time to bulk up.

Now that your diet and training routine are on point, you’re wanting to take your progress to the next level with the help of supplements.

One particular supplement that many hard gainers swear by is mass gainer.

But, a big worry that some folks have with taking mass gainer is that they’re scared it’ll make them poop.

So in this article, we cover whether mass gainer actually does make you poop, as well as the type of mass gainer you should be buying if you’re scared that you’ll need to poop.

Let’s get started.

Does Mass Gainer Make You Poop?

Mass gainer makes you poop as it’s usually high in creatine and artificial sweeteners. Both these ingredients can cause you to poop at high doses.

Why Mass Gainer Can Make You Poop

In this part of the article, we will explore reasons why mass gainer may make you need a poop.

To be clear, not everyone who uses mass gainer will need a mid-gym session poop.

But it covers possible reasons as to why some folks may need to rush to the toilet.

Mass Gainer Is Usually High In Artificial Sweeteners

Many supplements include artificial sweeteners as a low-calorie substitute to sugar.

But they can be hard to absorb and digest.

When undigested sweetener enters the bowel, your gut flora ferment it which produces methane and CO2.

As you may be aware, these are gases which may give you abdominal discomfort.

However, if you ingest a lot of artificial sweeteners, your gut flora may struggle to keep up with the demand.

When this happens, the undigested sweetener draws water into the bowel, resulting in you needing a poop.

This has been backed up by research too.

In one study, those who consumed 40g of isomalt each day had a significant increase in watery stools and bowel movements.

While you’re unlikely to consume this amount from mass gainer, you could still ingest enough to need a trip to the toilet afterwards.

Mass Gainer Is Usually High In Creatine

Creatine is a natural compound found in red meat and fish.

It’s included in many mass gainers as it helps increase ATP (i.e. energy) and muscle mass.

But when your muscles can’t take in any more creatine, any excess is converted to creatinine which is a waste product.

Our bodies tend to eliminate waste products like creatinine via our…

You guessed it.


Can Mass Gainers Cause Diarrhea?

As covered earlier, ingesting a large amount of artificial sweeteners can lead to watery stools, i.e. diarrhea.

So it’s possible that some mass gainers that are high in artificial sweeteners may cause diarrhea.

Do All Mass Gainers Make You Poop?

In short, no.

While most mass gainers are loaded with artificial sweeteners and creatine, there are some brands that offer mass gainers without these ingredients!

And since it’s these ingredients which make you need a poop, it makes sense that taking mass gainer without them wouldn’t result in a trip to the loo.

Does Taking Too Much Mass Gainer Make You Poop?

Logically, the more mass gainer you drink, the more likely you are to need a poop.


Well, the more mass gainer you drink, the more creatine and artificial sweeteners you consume.

And the more creatine and artificial sweeteners you consume, the more creatinine and undigested sweetener your body will have to deal with.

Should You Worry If You Poop A Lot After Taking Mass Gainer?

Absolutely not.

You need to remember that worrying is a negative emotion, and negative emotions can kill your appetite, making it harder to gain weight.

(Ironically, the opposite of what you want to achieve when taking mass gainer!)

The reason you shouldn’t worry is that you know exactly why you need to poop more.

Yes, pooping a lot can be a sign of something serious…

But if it only happens when you take mass gainer, then the chances of that are extremely slim!

Should You Stop Taking Mass Gainer If It Makes You Poop?

Generally speaking, there’s nothing wrong with taking mass gainer even if it makes you poop.

But if it’s affecting the quality of your workouts, then you might want to swap for a mass gainer that’s lower in creatine/artificial sweetener.

Best Mass Gainer That Won’t Make You Poop: Naked Mass

Click to see on Amazon


A high-quality mass gainer that’s free from creatine and artificial sweeteners.

Perfect for those who want to bulk up, without needing to run to the toilet.

What I Like About It

The unflavored tub of Naked Mass contains… wait for it…

3 ingredients.

That’s right…

A high-quality carb source in Organic Tapioca Maltodextrin.

And 2 high-quality protein sources in Whey Protein Concentrate, and Micellar Casein.

So you can forget about all the unwanted additives that creep there way into most other supplements these days.

All you’ll find here is pure natural goodness.

So without any creatine or artificial sweeteners, this is the go-to mass gainer supplement for those who want to control their bowel movements!

Potential Drawbacks

Like many other mass gainers, Naked Mass doesn’t come cheap.

But it’s a price worth paying in my eyes for such a high-quality supplement.

Check price and read more reviews of Naked Mass on Amazon.


In summary:

  • Weight gainer supplements can make you poop as they’re often high in calories, artificial sweeteners, and creatine.
  • The high amount of artificial sweeteners in mass gainer can cause diarrhea.

That’s all for this article, but does mass gainer cause acne? Or will you lose weight if you stop taking mass gainer?

Hope this helped!