Scientists found that we lose more nitrogen through our skin than previously thought—about three times more. This means the old guidelines for how much protein we need might be too low.

We analyzed the available evidence and found that nitrogen loss through the skin may be about three times higher than previously estimated [1]. This finding suggests that the body might be losing more protein-building blocks through the skin than earlier models accounted for. Based on what we’ve reviewed so far, this could mean that current protein intake recommendations, which were built on older assumptions, might not fully match what the body actually needs. The evidence we’ve reviewed leans toward the idea that skin-related nitrogen loss is a more significant factor than scientists once believed. However, we have not seen studies that directly test whether increasing protein intake based on this new number leads to better health outcomes, muscle retention, or recovery. We also haven’t seen data showing how this loss varies by age, activity level, or climate. While the numbers point to a possible gap in past protein guidelines, we don’t yet know how much more protein, if any, someone would need to compensate. The evidence doesn’t clarify whether this extra loss is easily made up through diet, or if other factors like gut absorption or muscle protein synthesis balance it out. What we’ve found so far opens a question—not a solution. It’s possible that protein needs are higher than we thought, but we can’t say yet how much higher, or if changing your diet will make a difference. More research is needed to connect the dots between skin nitrogen loss and actual protein requirements. For now, if you’re eating enough protein to feel strong, recover well, and maintain your weight, there’s no clear reason to change based on this finding alone.