Introduction: Skin photoaging is a multifactorial process mainly influenced by UVA and UVB radiation, UVB directly affects cells and extracellular components, UVA exerts its harmful effects mainly through active oxides. Active oxides destroy lipids and proteins in sebocytes, the extracellular matrix of the skin. It can cause erythema, inflammation, collagen damage, elastic fiber deformation and other phenomena. Photoaging skin manifests as: roughness, sagging and wrinkles. Retinoids can promote the generation of fibroblasts, reduce the degradation of collagen, increase and improve the amount of collagen in the skin, and are widely used in the prevention and treatment of skin photoaging. Retinoids include vitamin A and a range of other metabolites, such as retinol , retinaldehyde, retinyl esters, retinoic acid, and some syntheic derivatives, but retinoids will bring certain adverse reactions, such as dryness, erythema, desquamation, etc. Therefore, how to effectively and safely resist skin photoaging is very important. In this study, topical retinol combined with soy isoflavones was used to observe its efficacy and safety in resisting facial photoaging.

Methods: Select 30 subjects and use cream containing 0.1% retinol + 0.02% soy isoflavones on the face. After a 28-day observation period, the subjects' skin dryness, skin elasticity, dermis thickness and local wrinkle were evaluated, and safety assessment was evaluated through human patch test and consumer questionnaire test.

Results：The skin dryness, skin elasticity, dermal thickness and local wrinkles of the 30 subjects were improved, and there were no adverse reactions in the subjects during the test.

Discussion and Conclusion: External application of retinol combined with soy isoflavones can improve skin photoaging, which is safe and effective.