Cyclic Non-Polar Amino Acid Group (Proline) Proline is one of the amino acid used by organisms as a protein building block. Proline is the most interesting amino acid because its amino group is not free like other amino groups because it has a circular structure with another C atom, thus forming an aromatic structure65 . It can be syhthesized in our body from other compounds through chemical reaction such glutamic acid, it means that proline classified as non-essential amino acid. To increase the proline in human body then it can get through the food such as meat, milk and eggs. Apart from that, food is a source of intermediate proline others are cheese, soybeans, cabbage, bamboo shoots and yougurt, also by consuming supplements that we can get at the pharmacy. Having high proline in our body give more benefit such as production of collagen and cartilage, even keeping muscles and joint flexible, also it can treating sagging skin and wrinkles that caused by the influence of sunlight. Proline is a heterocyclic amino acid obtained from the hydrolysis of casein, and collagen contains a lot of proline and hydroxyproline66 . In cell proline play an important role by breaking down proteins that used in development and maintenance of skin tissue and connective tissue when the skin is injured. Proline also join another type of amino acid called lysine to make hydroxyporline and hydroxylysine to form collagen which used to healing cartilage and provideing protection for bone joints. Proline is not only needed to make cells, but to maintain healthmuscle tissue. The presence of proline in the body affects the strength of muscles to carry out their functions. In general, people usually have Proline enough in their bodies if they consume healthy food. But for those who are in certain conditions, they usually need to increase proline by consuming supplements.The dose required to consume proline is 500-100 mg. Meanwhile, consuming it can have side effects. One of them is causing low blood pressure. Apart from that, proline can also cause nervous disorders, stomach problems and allergic reactions.Consuming too high a dose of proline can also cause the citric acid cycle to become unbalanced, which will force the liver and kidneys to work harder.