Does Pea Protein Cause Gas? (Science-Backed Answer)


Pea protein powder is typically easier to digest than alternatives like whey protein.

However, it can still cause some gas. This is due to its relatively high oligosaccharide content.

If you’d like to understand how pea protein might be causing you gas, and what you can do about it, read on.

What Causes Gas?

Almost all gas is caused by carbohydrates, not protein.

Specifically, carbohydrates that aren’t easily digested and absorbed in the stomach and small intestine. You might know them as fiber, which is an umbrella term for many hard-to-digest carbohydrates.

These carbohydrates are then fermented by bacteria in the large intestine, which produces gas as a side product (e.g. methane). This can cause bloating and flatulence when enough gas is produced.

The Reason Pea Protein Shakes Don’t Usually Cause “Protein Farts”

Anyone who has regularly consumed whey protein shakes is aware that they often cause “protein farts.”

While there are some hard to digest sugars in dairy, protein farts are more marked by their smell than quantity.

Research has shown that most animal proteins (dairy, eggs, poultry, fish, etc.) have sulfur-containing compounds. Some of this sulfur gets released during flatulence which causes the strong, distinct smell.

Does Pea Protein Contain Anything That Would Cause Gas?

Plant-based proteins like pea protein have little to no sulfur in them, so any gas produced as a result typically doesn’t smell particularly worse than normal.

However, peas are relatively high in oligosaccharides, a particular type of fiber that is known to cause excessive gas.

Some people claim that antinutrients like lectins and phytates in legumes like peas cause gas, but it’s actually the oligosaccharides – raffinose in particular.

For better or worse, not much fiber is removed when pea protein powder is made. The table below shows the amount of fiber in 100 grams of either pure pea protein or whole peas.

  Now Sports Pea Protein Peas
Serving Size 100 g 100 g
Fiber 5 g 5.7 g

Note that a typical shake is 20-30 grams, so while the amount of fiber in protein shakes aren’t that high, the point is that the amount of oligosaccharides is still relatively high.


The main reason that pea protein causes some gas for many people is that it contains a significant amount of raffinose – an oligosaccharide (which is a carbohydrate that is hard to digest).

Why Else Might Pea Protein Powder Cause Gas?

One other possibility that explains gas from pea protein is an allergy or intolerance.

While not particularly common, pea protein allergies do exist. However, most common symptoms involve skin and breathing issues, not gas.

But food intolerances often cause digestive issues like excessive flatulence. It’s hard to diagnose a food intolerance, but you can look into an elimination diet if you suspect a pea intolerance.

Does Sprouted Pea Protein Powder Cause Less Gas?

Soaking and sprouting legumes reduces antinutrients and also allows oligosaccharides to seep out of the legumes (which are then drained away).

In theory, protein powder made with sprouted peas should have significantly less raffinose, adn cause less gas.

Unfortunately, there aren’t many sprouted pea protein powders out there, and the few that I have tried have tasted awful, so it’s not worth the trade-off.

Is There Anything You Can Do to Limit Gas From Pea Protein?

If your new pea protein shakes are giving you gas, all hope is not lost!

First, digestive issues are typically worse when you first introduce a new food into your diet. Your digestive system will get better at breaking down oligosaccharides up to a certain point over the course of a few weeks or months.

In addition, consider the following ways to limit any gas side effects:

  • Drink your shake slower – If you chug down a shake, all that fiber will hit the large intestine at the same time, resulting in a lot of fermentation and gas production, leading to bloating and flatulence. Try to drink it over a longer time period.
  • Get sprouted pea protein – As covered above, it will contain fewer oligosaccharides, making it easier to digest.
  • Buy a pea protein powder with digestive enzymes – Just because humans lack the enzymes to break down fiber directly, doesn’t mean they don’t exist. These enzymes (think beano) can break down the fiber in pea protein so that less fermentation is needed later on.

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. I've spent over 6 years as a freelance nutrition writer and researcher. During this time, I've tested over 50 vegan protein powders, and over 100 other types of vegan supplements.

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