My high school had a book series called Big Secrets, Bigger Secrets, and Even Bigger Secrets (or something like that). I remember reading in one of those books what some experts figured out the formula was. There is no way to be 110% certain since it is locked in a vault somewhere, but they were sure that they were right. I would imagine HPLC spectrums would reveal it, or very very close to it, same for supplements.