Serine is a small-molecule nonessential amino acid, the precursor of Glycine, thus involved in collagen synthesis. It is also a part of essential NMFs (natural moisturizing factors) preventing transepidermal water loss.
L-Serine is an integral component of particular phospholipids (fatty compounds, e.g., Phosphatidylserine) essential constituents of cellular membranes. Phosphatidylserine boosts procollagen production and inhibits collagen destructing enzyme called MMP-1.
In addition, l-Serine, in turn, is needed to produce another amino acid, tryptophan, that speeds up the wound healing process and skin recovery. It's a simple natural molecule involved in numerous processes in the skin, providing optimal hydration, improving dermal fiber contents, and stimulating healing.