Can collagen make your stomach run?

Can Collagen Affect Your Digestion?

Collagen supplements have surged in popularity, praised for their benefits to skin, joints, and hair. But some people wonder: can collagen upset your stomach? The short answer? It’s possible, but not common.

While collagen is generally considered safe for most people, a small number have reported mild digestive issues after taking it—things like nausea, diarrhea, or abdominal cramps. These side effects seem to vary from person to person and often depend on the form of collagen (powder, pill, liquid), the dosage, and individual sensitivity.

Most collagen supplements are derived from animal sources like bovine or marine collagen, and they’re broken down in the digestive tract just like dietary protein. For the majority, this process is smooth and causes no issues. However, some individuals may find that their stomach doesn’t tolerate certain brands or types, especially if the supplement contains added ingredients, fillers, or flavorings.

There’s currently no solid scientific evidence proving that collagen directly harms the stomach. In fact, some types of collagen, particularly type I and III, may even support gut lining health—though more research is needed in this area. If you experience discomfort, trying a different form (like hydrolyzed collagen peptides) or taking the supplement with food might help.

As with any supplement, listening to your body is key. If you’re unsure, talking to a healthcare provider can help you decide what’s best for your digestive health. In most cases, collagen is well-tolerated—and for many, the benefits outweigh the rare chance of a grumbling stomach.