Injectable non-crosslinked hyaluronic acid formulations in <i>dermal biorevitalisation</i> : a molecular and clinical evaluation

Injectable non-crosslinked hyaluronic acid-based formulations are widely incorporated into aesthetic treatment algorithms to improve dermal quality without providing structural volumisation. Two principal formulation strategies exist: (1) hyaluronic acid combined with broad metabolic cofactors, and (2) hyaluronic acid combined with defined structural amino acid complexes. This paper critically evaluates their molecular mechanisms, including cluster of differentiation 44 signaling, mitogen-activated protein kinase activation, phosphoinositide 3-kinase and protein kinase B pathways, transforming growth factor beta signaling, nuclear factor kappa B modulation, integrin cross-talk, mechanotransduction, lysyl oxidase regulation and collagen fibrillogenesis sequencing, and discusses current limitations within the clinical evidence base.