The development for the treatment of photodamaged skin has been enormous in the last decades. New concepts and better understanding of the aging process caused huge changes in the way dermatologists can treat their patients. Better equipments of lasers and lights, radiofrequency, ultrasound, 3D rejuvenation and volumization, botulinum toxin and their new targets, lifting sutures, and collagen enhancers among others are new tools always being renewed and reinvented. But one procedure remains unchanged, always the same since ancient times. Peelings actually have been increasing in number as a procedure in the last years. According to the Plastic Surgery Statistic Report (2014) of the American Society of Plastic Surgery, 1.2 million chemical peelings were performed in 2014 in the USA with an increase of 7% from 2013 to 2014. It is becoming more and more popular. It can renovate layers of cells and cause neocollagenesis. Superficial peels can bring back bright and clear skin in just few days. They are relatively simple procedures and inexpensive for dermatologists. Best results are achieved with a series of applications at short intervals.

Retinoic acid or tretinoin has been used for the treatment of acne for many years because of its comedolitic effect. It was been used for the treatment of actinic comedones (Kligman et al. 1971), for naevus comedonicus (Decherol et al. 1972), and for acne aestivalis (Mills and Kligman 1975). In 1983, Cordero published the first South American paper after observing unexpected improvement of periorbital wrinkles in patients that were been treating actinic comedones (Cordero 1983). The dosages he used at that time were 0.005–0.01%, with good and reproducible results and without the so-called “retinoic effect” that became so popular years after. In 1986, Kligman published the histopathological evidences of its rejuvenating effects in an article and in a special supplement of our Blue Journal, the Journal of the American Academy of Dermatology (Kligman et al. 1986). It became the best and the most popular agent for rejuvenation of the skin and for the treatment of solar damage, and it is still the best agent for those treatments. In the 1990s, it began to be used as a peeling agent when associated with 35% trichloroacetic acid medium peel resulting in a more uniform frosting of the skin and shortening the post-peeling recovery time (Brody et al. 2000). At that time emerges the retinoic acid peels for various indications.

“The mechanical action of the peeling, even when limited to the epidermis, is able to stimulate regeneration via pathways in the dermis that are not totally understood” (Fischer et al. 2010)

We do know that the mechanism of action is characterized by thinning and compression of the stratum corneum, reversal of epidermal cells atypias, dispersion of melanin in the epidermis, stimulation of dermal deposition of collagen, increased deposition of glycosaminoglycans, and neovascularization (Yokomizo et al. 2013).

Retinoic acid has the property of making neocollagenesis and cellular renovation accelerating the cellular turnover of keratinocytes. It is comedolitic and a depigmenting agent, as it inhibits tyrosinosis and TIRP-1. There are also other mechanisms associated with the activation of nuclear retinoic acid receptors (RARα, RARβ, and RARγ) (Baldwin et al. 2010).