L-Proline: Skin Benefits, Foods, + More

What Is L-Proline?

L-proline is an amino acid. Amino acids are molecules that, when linked together in chains, form proteins in the body. So, amino acids are like letters of an alphabet used to form words. The specific number and sequence of amino acids determines the shape and function of the protein. Proteins are utilized in all sorts of roles in the body, including those involved in tissue structure and cellular regulation. 

The human body uses twenty different amino acids to function correctly. Nine of these amino acids are called essential amino acids and must be consumed in the diet. L-proline and ten other amino acids can be formed in the body and are termed non-essential amino acids. However, supplying non-essential amino acids like L-proline can provide important support during times of increased need.

What Does L-Proline Do?

L-proline was isolated from gelatin in 1901. Its name is derived from the Greek word “prolos,” which means “before glue” and signifies its sticky nature. It is used in the body primarily to form collagen, whose name also comes from the Greek word for glue. Collagen, along with hyaluronic acid (a sticky mucopolysaccharide) and elastin, forms the ground substance or “intracellular cement” that literally holds the cells of the body together. 

Skin Benefits

L-proline is extremely important to health since collagen accounts for 30% of total body protein and up to 70% of the proteins in our skin and connective tissues, such as tendons, ligaments, cartilage, bone, and blood vessels. 

The primary use of L-proline supplements mirrors the uses of collagen peptides. Specifically, L-proline can help support collagen synthesis to support the health of collagen-rich tissues such as the joints and skin.¹ L-proline may also help promote wound healing.² During the early phases of wound healing, proline levels increase in areas of damage to be used to support the formation of new collagen to help promote healing. L-proline may also help promote improved gut barrier function and immune function.³ 

L-Proline Foods

L-proline is found in collagen-rich foods or supplements. Animal-based sources include meat, bone broth, gelatin, dairy products, and eggs. Good plant-based sources include legumes, soy foods, and nuts. 

L-Proline Dosage

A typical diet generally provides about 5 grams of L-proline per day. To boost L-proline intake, high L-proline foods can be increased. Supplementation with L-proline is generally recommended at a dosage of 500mg two to three times daily.

References:

1. Murakami H, Shimbo K, Inoue Y, et al. Importance of amino acid composition to improve skin collagen protein synthesis rates in UV-irradiated mice. Amino Acids. 2012 Jun;42(6):2481-9. 
2. Barbul A. Proline precursors to sustain Mammalian collagen synthesis. J Nutr. 2008 Oct;138(10):2021S-2024S. 
3. Ruth MR, Field CJ. The immune modifying effects of amino acids on gut-associated lymphoid tissue. J Anim Sci Biotechnol. 2013 Jul 30;4(1):27.