Peptides are short sequences of amino acids. Amino acids are also the building block of proteins, but proteins consist of much longer sequences of amino acids, usually fifty or more. Peptides are much shorter in length, as little as two or three amino acids linked together. Peptides are found naturally in the human body where they serve a variety of functions. Some peptides alter bodily functions by serving as hormones while others act as signaling molecules, allowing cells to communicate with one another. Peptides are also increasingly being used in cosmetic and skin care products for their skin anti-aging benefits.
Peptides act as signaling molecules in skin just as they do in other parts of the body. One type of peptide called palmitoyl oligopeptide signals cells in the dermis of the skin called fibroblasts to produce collagen. Collagen is the primary protein that gives skin its support and youthful firmness. Collagen levels decline with age and with sun exposure, and this accounts for the loss of firmness and skin wrinkling that appears as people age. Palmitoyl oligopeptide also appears to increase the amount of hyaluronic acid in skin so that skin retains more water. That's why palmitoyl oligopeptide is an ingredient in some moisturizers and anti-aging products formulated for more mature skin.
Boosting collagen production isn't the only skin care benefit that peptides have. Some types of skin peptides called neuropeptides have benefits similar to Botox, an injectable protein used to treat dynamic wrinkles, those which are visible with facial movement, by relaxing the underlying muscles involved in forming the wrinkles. The problem with Botox is it has to be injected underneath the skin by a professional to have benefits, and this can be expensive. A neuropeptide called argireline appears to be absorbed through the skin where it reaches the muscle and exerts a Botox-like effect on the muscle. This reduces the appearance of dynamic lines and wrinkles, creating a more youthful-looking face without the requirement for needles or injections. Argireline is currently available in some wrinkle creams.
Some of the oldest skin peptides are copper peptides. Copper peptides consist of a peptide with a copper molecule attached. Peptides are short sequences of amino acids and are therefore small in size. This means they can easily penetrate the skin and carry copper along with it. Copper peptides have several benefits when they reach the dermal layer of the skin. They promote wound healing, act as antioxidants, reduce inflammation and stimulate the production of collagen. Delivering antioxidants to the dermis may help to offset damage due to sun exposure and increased collagen production increases skin firmness and reduces the appearance of lines and wrinkles. Copper peptides can be found in facial moisturizers, eye creams and other anti-aging products.