Collagen stimulants in facial rejuvenation: a systematic review

Ageing is a multifactorial process that affects different layers of the anatomy leading to, at the deepest level, bone resorption and remodelling, resulting in overlying fat redistribution compounded by fat loss, muscle atrophy and, at skin level, dermal ageing through collagen loss. Collagen synthesis stimulants are, therefore, very attractive solutions to the dermal aspect of this complex ageing process (Rohrich and Pessa, 2007; Mendelson and Wong, 2012). Initially, these agents will always cause a foreign body reaction when first injected into the host tissue (Strawford, 2020). Collagen stimulation results as part of the normal healing response of the body. After the inflammatory phase, initially producing type III collagen, microparticles of the filler become encapsulated as part of a natural protective mechanism (Strawford, 2020). This mechanism produces a stable capsule of mainly type I collagen and lasts as long as the biomaterial is present within the tissue (Strawford, 2020).