The amino acid L-Proline, while famous for its power to heal all connective tissue injuries, also strengthens the heart, in addition to the joints, tendons, and cartilage. Because it’s an essential component of collagen, L-Proline is critical for maintaining youthful skin and helping repair muscle, connective tissue and all forms of skin damage thus minimizing the effects of aging. Without an adequate supply of L-Proline, joints and tendons will not function properly, nor will the heart muscle be as strong as it should be. Taking L-Proline along with Dr. Dane’s Super C Complex is a fantastic way to promote healthy connective tissue. 60 Capsules.