The ability of topical retinoic acid, also termed tretinoin, to improve photoaging changes in skin Topical retinoids are the mainstay of treatment of patients with mild to moderate photoaging.

Retinoids are a class of naturally occurring or synthetic compounds related to vitamin A, also known as retinol. Retinol is naturally converted in the body to its most biologically active form,retinoic acid, as well as to its other derivatives, retinaldehyde and retinyl ester. Various natural and synthetic retinoids increase collagen production, induce epidermal hyperplasia, and decrease keratinocyte and melanocyte atypia. they reduce the appearance of fine lines, improve skin texture, correct tone and elasticity, and slow the progression of photoaging.

Topical retinoids may cause irritant reactions, such as scaling, redness, burning, and dermatitis, limiting patient compliance. Retinoids should be initiated at the lowest effective dose to minimize adverse effects.

Alpha-hydroxy acids (AHA) are compounds derived from dairy products (lactic acid), fruit (malic acid and citric acid), or sugar cane (glycolicacid).

Topical treatment of photodamaged skin with AHA has been reported to improve wrinkling, roughness, and dyspigmentation within months of daily application.

Free radicals have long been studied as a contributor to aging and disease processes. Endogenous production of radicals from cellular metabolism and exogenous sources from ultraviolet radiation and pollution can damage the skin on the cellular and tissue levels.

Although the body possesses an elegant defense system to prevent radical damage,this innate system can be overwhelmed and lead to a state of oxidative stress or immunosuppression and can even trigger carcinogenesis. Antioxidants can provide additional protection to neutralize reactive oxygen species from both endogenous and exogenous sources.

It reduces pigment darkening by inhibiting tyrosinase and maintains hydration by protecting the epidermal barrier of the skin . Application of topical L-ascorbic acid has been shown to have photoprotective effects including the reduction of erythema, sunburn cell formation, and immunosuppression.

Vitamins C and E work in conjunction in an elaborate network of redox reactions to stave off oxidative stress.