Eggs have a special kind of protein that helps your body keep more nitrogen instead of losing it in urine, which helps your muscles and tissues grow better.

We analyzed one assertion about whether eggs promote positive nitrogen balance by reducing urinary nitrogen loss, and found no support for it. In fact, 25 studies or assertions directly contradict this idea. The claim that eggs contain a special protein helping the body retain nitrogen instead of losing it in urine does not align with the evidence we’ve reviewed. Nitrogen balance refers to how much nitrogen your body keeps versus how much it excretes — often used as a rough indicator of muscle building or tissue repair. But according to the data we’ve examined, eggs do not appear to have a unique effect on reducing nitrogen loss through urine. What we’ve found so far suggests that while eggs are a source of high-quality protein, there is no clear link between eating them and improved nitrogen retention compared to other protein sources. The idea that eggs somehow “special” in this regard isn’t backed by the available research. This doesn’t mean eggs are bad for muscle health — they’re still nutrient-dense and provide essential amino acids — but the specific mechanism described in the assertion isn’t supported. Our current analysis shows that if you’re eating eggs for muscle growth or recovery, it’s likely because of their overall protein content, not because they uniquely reduce nitrogen loss. There’s no evidence to suggest you’d gain an advantage over other protein-rich foods by choosing eggs for this reason. In everyday terms: eating eggs won’t help your body hold onto nitrogen better than other proteins — so don’t rely on them for some special nitrogen-saving effect. Just enjoy them as part of a balanced diet.