Hi  – collagen is a protein, but it’s not a complete protein meaning it doesn’t contain an adequate proportion of all 9 essential amino acids. 

Our body needs 20 different amino acids to grow and function properly but only 9 of them are classified as “essential”.  “Essential” means we can’t make it, but we need it, so it must be supplied by our diet.

Animal products provide complete sources of protein and so do soybean and quinoa in the plant world.

However, bone broth and collagen protein, while not complete, are good additions since they are high in glycine – a non-essential amino acid lacking in today’s diet due to higher consumption of muscle meat vs. consumption of skin, connective tissues, ligaments, cartilage and bones.

Hope that helps clarify the issue.