Tretinoin is the chemical name for one member of a family of compounds called retinoids, which are related to vitamin A. Vitamin A acts at the cellular level to encourage both the secretion of mucus between the cells and normal cell development. It is uncertain how tretinoin specifically affects the biological function of skin cells, although it is thought to thin the top layer of the skin and to increase its blood supply. This accelerates the rate at which the skin is renewed. Tretinoin is also thought to improve the alignment of collagen in the dermis, preventing it from clumping up, as occurs with sun related wrinkling.

Much of the initial improvement seen with tretinoin is likely caused by the swelling of skin due to irritation. Fluid shifts occur with inflammation, and this temporarily smoothes out the fine wrinkles. Subsequently, the collagen realigns itself and a more permanent reversal of wrinkling occurs.

Research has shown two additional benefits of tretinoin. It has proven effective in reducing or eliminating precancerous, sun damaged spots. it also changes the skin's ability to retain water by increasing its mucus levels. By raising the water content of the skin, wrinkles swell and become less obvious.

Tretinoin is available by prescription in products such as Stieva A, Retisol A, Vitamin A Acid Retin A, Rejuva A, and Renova. It is the variation in concentrations and vehicles in which the tretinoin are carried that differentiate between these products. For example Stieva A and Retin A are carried in gels, creams, and liquids in concentrations which vary from 0. 0 1 % (low) to 0. 1 % (high).

Retisol A is carried in a moisturizing cream which also contains a PABA free broad spectrum sunscreen which protects against UVA and UVB rays of light. The moisturizing base is noncomedogenic so it does not aggravate acne prone skin. It can be obtained in concentrations varying from 0. 0 1 % to 0. 1 %. For the busy individual who does not want to fuss with a lot of different creams this is an excellent option.

Rejuva-A and Renova contain mid level concentrations of tretinoin. Like Retisol A these products marry the benefits of tretinoin and noncomedogenic moisturizers. The goal is to control the redness and irritation that is problematic with higher concentrations of tretinoin.