Retinol for tightening enlarged pores?

The pores are small openings located at the end of the pilosebaceous ducts, connecting the sebaceous glands to the external environment. They are essential for the evacuation of sebum but sometimes they dilate excessively and become visible, posing an aesthetic problem and promoting the appearance of imperfections. Pores are generally considered enlarged when their diameter fluctuates between 0.06 and 0.1 mm. There are three main causes of dilation: excessive sebum production, a significant amount of dead cells accumulated in the pores, and natural ageing, the decrease in collagen levels with age tending to cause a relaxation in the structure of the pores.

Maintaining a skincare routine that includes astringent and keratolytic agents can help reduce the appearance of enlarged pores.

The retinol, a derivative of vitamin A, could be particularly helpful. Indeed, when applied to the skin, retinol undergoes two successive conversions to transform into retinoic acid, its biologically active form. This then binds to the nuclear receptors of retinoic acid (RAR) and the retinoid X receptor (RXR), which results in the formation of an activated RAR/RXR heterodimeric complex, responsible for transmitting the retinoid signal in cells. The RAR/RXR complex then binds to retinoic acid response elements (RARE), a specific area of DNA, which allows for normalising cell differentiation. In doing so, the retinol prevents the accumulation of dead cells on the skin's surface, one of the factors involved in pore enlargement. Retinol is also attributed with the ability to regulate sebum production, but, while this property has been widely demonstrated in vitro, clinical studies on this subject are still lacking.

However, there are several clinical studies that have demonstrated the efficacy of retinol and retinoids in general for improving the appearance of pores. One such study was conducted with 568 volunteers and examined the effects of a cream containing 0.1% tazarotene, an acetylenic retinoid, compared to the same formulation without tazarotene. After application for 24 weeks, a significantly greater reduction in pore size was observed by the researchers in the group that received the cream with tazarotene. This was measured using a 5-point scale (0 = barely visible, 1 = very small, 2 = small, 3 = medium and 4 = large).

Finally, we can reference a study conducted with 120 women divided into two groups. The first group received a cream containing 0.2% retinol and 2% jasmonic acid, a compound known for its positive effects on wound healing and tissue regeneration. The second group received a treatment based on 0.025% tretinoin, one of the most effective retinoids but only available on medical prescription. For 84 days, the participants applied one or the other of these creams to their face. A dermatoscope was then used to monitor, among other things, the evolution of pore size. After 84 days, a significant reduction in pore dilation was recorded in both groups. This reduction was on average 30.6% for the volunteers who received the cream with retinol and 37.5% for those who received the treatment with tretinoin. Although better results were obtained in the "tretinoin" group, retinol still demonstrated a good ability to tighten enlarged pores. Furthermore, better skin tolerance and fewer redness were noted in the "retinol" group.

These various results appear to suggest that retinol is a beneficial active ingredient for tightening enlarged pores.

• GIBSON J. R. & al. A multicenter, randomized, double-blind trial of tazarotene 0.1% cream in the treatment of photodamage. Journal of the American Academy of Dermatology (2005).

• ISSA M. C. & al. A double-blind randomized study comparing the association of Retinol and LR2412 with tretinoin 0.025% in photoaged skin. Journal of Cosmetic Dermatology (2015).

• GOLDENBERG G. & al. Enlarged Facial Pores: An Update on Treatments. Cutis (2016).

• MILLER R. A. & al. Oily Skin: A review of Treatment Options. Journal of Clinical and Aesthetic Dermatology (2017).