Two tubs can both say “protein” while serving different purposes. If your goal is supporting muscle, the relevant comparison is not just the number printed on the front. A study in older men tested several sources and found different short-term muscle responses.

What the research found

A controlled study in 31 older men compared added whey, pea and collagen protein over eight days. Integrated muscle protein synthesis increased with whey and pea, but not collagen. The study measured a short-term biological response rather than long-term gains in muscle size or strength. [1]

These findings are specific to the participants and feeding conditions studied. A muscle-protein-synthesis result is informative, but it is not a direct forecast of months of training progress.

Buy for the outcome you want

Do not assume a collagen product can replace any other protein source merely because both contribute grams of protein. Read what the supporting research measured and choose in the context of your meals. This study addresses muscle synthesis; it is not a verdict on every other claim made for collagen.

Putting it into perspective

Someone buying collagen for a different reason may notice its protein content and assume it covers a muscle-related goal too. The study suggests that this substitution deserves scrutiny. Read the intended use and the outcome separately: one product can contain protein without being interchangeable with the comparison sources in this experiment.