• Hydrolysed collagen and collagen peptide formulas are available in the form of pills or powder, and can be derived from porcine, bovine or marine animals. The differences in the AA content of various animal and human collagen sources are presented in Table 1. Recent research has shown there is no significant difference in plasma availability of key AAs after the consumption of various collagen protein sources.¹⁶ Therefore, the source of collagen is unlikely to influence its’ effectiveness.
• Collagen in the form of gelatin is considered as a food product, and therefore, does not require batch-testing for use in athletes., Where access and/or budget is a consideration, gelatin may be a preferential option, especially if made into more palatable jellies or jubes.
• Some collagen formulations include ascorbic acid, due to its role as a cofactor in collagen synthesis.¹⁷ However, whether there is benefit beyond dietary sufficiency of ascorbic acid for collagen synthesis remains to be determined.
• Unfortunately, Australian food databases do not contain information on the collagen content of foodstuffs (measured as hydroxyproline), and therefore, it is not possible to determine collagen intake through food sources. Further, research has indicated that the AA content of collagen in bone broth, is too variable to use as a therapeutic source of collagen.²⁷

Table 1: Amino acid composition of the 5 major mammalian collagens and gelatin

Amounts given in grams per 100 grams of dry ash-free Protein. Adapted from.²⁸