Why Protein Powders Make You Fart—and What You Can Do About It
Key Points
Whether your goal is to get stronger or build muscle, protein powder may be a regular part of your routine. While these powders can be a quick, convenient way to bump up your protein intake, some may come with an unexpected side effect, namely gas. It’s not just you. The phenomenon is so common that protein powder enthusiasts have even come up with a name for them: “protein farts.”
While gas is a normal byproduct of digestions, too much of it can be uncomfortable, not to mention embarrassing. “Not all powders will cause this, and reactions are often very individualized,” says a medical expert. “I find that the more potential ingredients there are in a powder that we know can cause gas and bloating, the greater the likelihood that you will experience them.”
Why, exactly, does protein powder make some people fart? To find out, we asked sports dietitians. Here’s what they told us, plus what you can do to prevent it from happening.
Why Protein Powder Might Make You Gassy
It May Contain Artificial Sweeteners or Sugar Substitutes
Some protein powders are sweetened with artificial sweeteners or sugar substitutes to improve their flavor without added sugar or extra calories. Unfortunately, those same ingredients can cause excess gas and digestive upset for some people. “Additives and sugar substitutes, such as sugar alcohols, gums and added fibers can contribute to GI distress because they are not fully digested in the small intestine and are subsequently fermented in the large intestine,” says a medical expert. “The fermentation process creates gas as a byproduct and frequently causes issues such as bloating and abdominal discomfort.”
These sweeteners won’t affect everyone adversely. However, people with digestive sensitivities or conditions like irritable bowel syndrome (IBS) may be more sensitive to them. “Rather than avoiding them entirely, it’s often helpful to choose powders with simpler ingredient lists and use trial and error to find what your body tolerates best,” says Jones.
You’re Lactose Intolerant
“If protein powder is whey-based, depending on the type of whey protein included, the powder may also include some lactose, which is the sugar found in milk,” says Garay. If you’re lactose intolerant, this can lead to digestive discomfort, excess bloating and gas. “For someone who is lactose intolerant, they can still use a whey protein powder but will want to look for a product that contains whey protein isolate or whey protein hydrolysate as the ingredient,” says an expert. “These forms of whey protein have very little lactose.”
Just know they aren’t 100% lactose free.4 If you’re especially sensitive to lactose, look for lactose-free plant protein powders, such as pea or soy protein powders. Or, consider other plant-based protein powders made from hemp, corn, brown rice or a variety of seeds.
It May Contain Lots of Fiber
Some protein powders include more than just protein, which is why it’s essential to carefully read the label before trying them. “If protein powder contains plant-based sources of protein, then there may also be relatively high amounts of fiber or other substances (e.g., oligosaccharides) that can cause gas or bloating,” says Garay. While consuming more fiber than your gut is used to can be uncomfortable for anyone, people with IBS or other gastrointestinal conditions may be even more likely to experience symptoms from fiber-heavy protein powders.
You may find large amounts of fiber in products marketed to improve gut health. It’s also commonly added to protein powders designed as meal replacements. This fiber can come from a variety of ingredients, including chicory root or inulin, guar or xanthan gum, psyllium husk, chia seed powder or oat-based fiber.
Tips to Reduce Symptoms
Getting extra protein from a powder or shake doesn’t have to lead to uncomfortable gas or bloating. These tips can help you choose the best protein powder to minimize symptoms.
- Start Small: Consider using a half-serving or even a quarter-serving of protein powder when starting a new product. Some companies offer sample packs to make this easier without a significant financial investment. “Mixing with sufficient water and drinking it more slowly can also improve tolerance,” says Jones.
- Read the Label: “Check the ingredients list to make sure there is no sugar alcohol (ingredients ending in “-itol”) or chicory root or inulin, which are most likely to be poorly digested and cause GI upset,” says a Dr. Choosing an unflavored powder without added fiber can be a good place to start.
- Switch Protein Powders: “If symptoms persist, trying a different protein source such as plant-based (e.g., pea, soy, rice) or egg white protein is often helpful,” says Jones.
- Choose Independently Tested Supplements: Supplements are not regulated the same way as food.7 How can you know if yours contains what the label says? “Make sure it is tested by a company such as USP, NSF Informed Choice or Informed Sport, which confirms that the product does not contain any banned substances or ingredients which are not listed on the label,” says a Dr..
- Prioritize Protein from Food: Most nutrition experts agree that your primary source of protein should be food, not supplements. If you experience GI upset from protein powders, it can be especially helpful to prioritize whole foods over supplements. “I remind all my clients that rarely are protein products our only option, and we can adjust the diet if we can’t find a protein powder that is beneficial,” says an expert. “Supplements are meant to supplement the diet.”
Our Expert Take
Protein powders can cause uncomfortable bloating and excess gas, also known as “protein farts.” This may be due to their lactose, fiber or sweeteners. The good news is, you don’t have to give up protein powder entirely. You’ll just want to know what to look for. “There are many types of protein powders that can meet your needs,” says Christensen. “For example, if you are sensitive to the lactose, then look for a protein powder with a whey isolate (lower lactose) or a protein powder that is dairy-free like pea, soy or rice protein powders. If you are sensitive to sugar alcohols or artificial sweeteners, then look for a protein powder that does not contain ingredients like sorbitol, xylitol or sucralose.” It may take some experimentation, but a little trial and error can go a long way in preventing discomfort.