A protein that has already been broken down, usually by enzymes, and is a mixture of free-form, di-peptide, and tri-peptide amino acids.
Hydrolyzed Protein is protein that has been hydrolyzed or broken down into its component amino acids. While there are many means of achieving this, two of the most common are prolonged boiling in a strong acid or base or using an enzyme such as the pancreatic enzyme to stimulate the naturally-occurring hydrolytic process.