According to the NIH Office of Dietary Supplements, primarily found in animal-based foods such as meat, fish, eggs, and dairy which is why reduced intake of these foods may gradually affect consistency over time
Unlike other growth hormone secretagogues, it appears to selectively promote growth hormone release without markedly affecting prolactin, TSH, ACTH, LH, or cortisol
Intrigued, I started researching
(To learn more about building healthy bones and where to get these nutrients on a Paleo diet, check out this article.) As for joint health, lubrication by GAGs is the key to a full range of motion, whereby part of one bone can slide smoothly and painlessly over part of another
[General protein/peptide stability reference] Lam XM, et al
Reactive oxygen as modulator of TNF and fas receptor-mediated apoptosis in vivo : studies with glutathione peroxidase-deficient mice