CNP ProGlutamine Powder contains 100% pure l-glutamine, the most abundant amino acid in muscle. Glutamine is an amino supplement Amino acids are the building blocks of protein. Glutamine is flavourless and can easily be added to your favourite protein supplement, formula, or weight gainer or simply with water or juice. CNP ProGlutamine Powder contains 100% pure l-glutamine, the most abundant amino acid in muscle. Glutamine is an amino supplement Amino acids are the building blocks of protein. Glutamine is flavourless and can easily be added to your favourite protein supplement, formula, or weight gainer or simply with water or juice.