PCA Skin ExLinea Peptide Smoothing Serum. is a peptide product packed with chirally-correct ingredients that smooth, hydrate and nurture aging skin. Formulated to smooth out existing lines and helps prevent further facial wrinkling, this product also helps your skin retain moisture and provides a plumper, firmer complexion. Its antioxidants suppress free radical damage and help fight the aging process. A study in the International Journal of Cosmetic Science has demonstrated that regular use of the peptide in this product dramatically reduced the depth of existing wrinkles and relaxed the facial muscle contractions that are believed to cause new lines.