I started taking this after reading that L-Proline is good for the skin. In the few short weeks I have been taking this supplement, I have noticed that my skin is slightly firmer and softer. I cannot say at this point if it is due just to the L-Proline, but before I was tacking C and L-Lysine. The result has not been as good without this product. I take a 1000 mg daily, and will continue to do so. It seems to be working. Great stuff. Give this product a try!