Proline is an amino acid that helps collagen to form. Proline is well-proven to improve skin health and appearance. Besides its anti-aging effects and ability to repair damaged skin, other functions of proline include supporting the immune system, improving antioxidant status, improving gut health and nutrient absorption, supporting the metabolism, and protecting the cardiovascular system. People with poor skin health, slow healing, joint pain, gastrointestinal problems, and a high risk for heart disease can likely all benefit from getting more of this amino acid.