General Info


L-Proline is readily absorbed from within the small intestine.

Dietary Origins

L-Proline is produced by glutamic acid within the body. It can also be found in natural sources of meat, dairy and eggs.


Proline is one of the twenty common amino acids that forms proteins and is the only cyclic amino acid. The “L” in front of its name denotes the active form of proline. Amino acids are essential to life and the human body is reliant on proper dietary intake to survive. The underlying cause of many diseases not associated with infection results from a problem with protein assimilation. It is contained within cartilage, and is essential for proper maintenance of collagen.

In studies done in vivo and vitro, L-proline was found to be the only amino acid that was involved in the stimulation of DNA synthesis. Further epidermal growth factor (EGF) elicited no response without the addition of L-proline. L-proline deficient media such as Leibovitz’s L-15, Eagle’s minimal essential did not induce DNA synthesis. However, using media such as Williams E, McCoy’s 5A and Ham’s F-12, which are rich in L-proline, there was DNA synthesis and marked proliferation.

Toxicities & Precautions


There are no known toxicities or precautions associated with proline.

Side Effects

There are no known side effects related to the use of proline in supplemental use.

Functions in the Body


Proline and lysine, another amino acid, are both needed to make hydroxyproline and hydroxylysine, two amino acids that form collagen. Improper production of collagen has been linked to genetic disorders that result in joint and spine problems.

Cell Health

Helps the body break down proteins for use in creating healthy cells throughout the body.

Immune System

It is a necessary amino acid for a healthy immune system.

Symptoms & Causes of Deficiency

Proline is naturally produced within the human body. As the human body grows older levels may become diminished, resulting in debilitating bone and joint disorders. A deficiency of proline within the body may result in a weakened immune system, joint and spine disorders, and increased cell death.