Cosmetic peptides
Peptides have a wide application in medicine, including dermatology. It is not surprising that these biological molecules have been a target in cosmeceuticals, particularly due to their safety and ease of modification. In cosmetics, peptides have been used to prevent skin aging by targeting the skin growth factors, hence regenerating collagen and restoring the elasticity of the skin. These cosmetic peptides are leading a beauty revolution with their multi-functional properties, including their ability to regulate certain biological functions.

Cosmetic peptides are one of the active components of modern day cosmetic preparation. A cosmetic product has the property of activating the melanogenesis, being an anti-inflammatory, and acting more efficiently. Acetyl hexapeptide-3, Palmitoyl Pentapeptide, Palmitoyl hexapeptide, Palmitoyl Tetrapeptide-3, PAL-GHK are some of the common cosmetic peptides.

Acetyl Hexapeptide-3, a synthetic anti-aging cosmetic ingredient derived from natural proteins. The palmitoyl in palmitoyl pentapeptide, or pal-KTTKS, is derived from interferon-alpha. Palmitoyl Tetrapeptide-3 is a synthetic peptide that is a fragment of immunoglobulin G. Palmitoyl Tetrapeptide-3 was discovered through research to learn how to suppress the body’s production of interleukins (IL6).

Structural Characteristics
Palmitoyl pentapeptide is a derivative of the pro-collagen I pentapeptide, a chain of five amino acid fragments lysine-threonine-threonine-lysine-serine also known as the KTTKS peptide. Palmitoyl Hexapeptide-14 is a short bioactive peptide modified with palmitoyl.
  • The sequence of palmitoyl hexapeptide is Pal-Val-Gly-Val-Ala-Pro-Gly-OH.
  • The sequence of Palmitoyl Tetrapeptide-3 isPal-Gly-Gln-Pro-Arg-OH.
  • The sequence of Acetyl Hexapeptide-3 is Ac-Glu-Glu-Met-Gln-Arg-Arg-OH
Mode of Action
Acetyl Hexapeptide-3 acts as a wrinkle preventative by competing with SNAP-25 for a position in the SNARE complex. This destabilizes the SNARE complex, preventing the vesicle from releasing neurotransmitters efficiently, and therefore attenuating muscle contraction. This causes a reduction in facial muscle contraction, which is believed to help prevent the long-term formation of lines and wrinkles. The second way that Acetyl Hexapeptide-3 acts as a wrinkle preventative is by reducing the release of catecholamines (the overproduction of which is known to induce the formation of wrinkles and fine lines in the skin), specifically adrenaline and noradrenaline.

Palmitoyl Pentapeptide creates a response in the dermis of the skin that stimulates collagen and elastin fibroblasts, developing fibronectin (FN) and glycosaminoglycans (GAG).
Palmitoyl tetrapeptide is believed to work by reducing the production of interleukin-6 (IL-6) by the key skin cells, keratinocytes and fibroblasts. IL-6 is a molecule that promotes inflammation, which, in turn, leads to faster degradation of the skin matrix and thus contributes to the development of wrinkles and loss of skin firmness and elasticity. By reducing the levels of IL-6 and possibly other inflammation mediators, palmitoyl tetrapeptide is thought to slow down the degradation of the skin matrix and may also stimulate its replenishment.

Acetyl Hexapeptide 3 temporarily limits the overproduction and release of neurotransmitters that initiate and control the intensity of facial muscle contractions. At a 10% concentration, Acetyl Hexapeptide 3 has been shown to reduce the depth of wrinkles up to 30% after 30 days of trial use. Argireline is a peptide (acetyl hexapeptide-3) that inhibits SNARE complex formation and catecholamine release, resulting in the reduction of the degree of existing facial wrinkles.

Palmitoyl Pentapeptide stimulates production of dermal matrix components (in particular collagen) which is believed to be involved in its skin activity. Pal-KTTKS is also reported to be involved in thickening of epidermis and reduction in aging skin’s excess production of dermal glycosaminoglycan (GAG).