Both are effective. And both can be taken together depending on your goals.  Type II collagen produces a novel effect in the body. It regulates the immune response responsible for inter-cartilaginous inflammation, supporting the overall healing process and helping manage joint discomfort.  Collagen peptides (aka Collagen Protein) are primarily made of Types I and III, which have different mechanisms and effects. They help kick-start the machinery that builds new collagen and optimizes tissue formation.  Type II primarily protects against and helps with inflammation. Types I and III (what's in Collagen Synthesis) primarily serve as building agents.