HealthWise® L-Proline is 100% pure pharmaceutical grade amino acid powder. L-Proline is the amino acid necessary for the production of collagen and cartilage. Proline is actively involved in the body's production of glutamic acid and also helps prevent build-up of atherosclerotic deposits. Did you know? Virtually all of the proteins in the human body contain L-Proline. Plants also use proline to generate tissues such as pollen.