can collagen peptides cause constipation?

Biologically, collagen peptides are actually known to support gut health. The amino acids glycine and glutamine help strengthen the lining of the intestinal tract.
However, protein requires a lot of water to metabolize. If consumers take dry collagen powder in a tiny shot of espresso and don’t drink water the rest of the day, their gastrointestinal motility will slow down. It’s simply a matter of the body pulling water from the colon to process the heavy protein load.

Ariana is right—it’s a macronutrient issue, not a collagen-specific issue. Pure collagen peptides contain absolutely zero dietary fiber.
From a formulation strategy standpoint, this presents a great opportunity. To combat this potential side effect, I often suggest my clients formulate a “Gut Health Collagen Blend.” We take a high-quality hydrolyzed peptide base and blend it with soluble fibers (like inulin or acacia fiber) and some probiotics. It completely eliminates the constipation issue and allows the brand to charge a premium for a multi-functional product.

We monitor customer feedback very closely, and while it’s relatively rare, we do occasionally get complaints about constipation.
Usually, it happens when a customer who normally has a low-protein diet suddenly starts taking 20g of pure collagen every day. Any sudden increase in protein intake without a corresponding increase in water consumption can slow down digestion. We train our customer service team to advise users to increase their hydration and start with a smaller dosage before working their way up to a full scoop.