From a prominent seller of SAAs:
"This amino acid blend is formed using the free-flow amino acids to replicate the series of aminos that appear in silk. They are not hydrolyzed from silk protein."
As if they weren't overhyped and mis-marketed enough, you aren't even getting actual SAAs, you're just getting a mix of amino acids meant to mimc SAAs.
That means no Sericin-L or Sericin-S polypeptides for you. Which kind of defeats the purpose of SAAs.
Go supplement industry!