It’s no secret that the skin is the largest organ in the body and requires care and protection to keep it looking healthy and glowing.

If you’re eager to turn dry and dull into dewy and radiant skin, having an understanding of our skin’s biology and structure is so important. After all, it not only enables us to appreciate the magic of our skin’s tiny cells, but also see the importance of skincare. 

The skin’s biology

The skin has three layers – the epidermis, dermis, and the hypodermis¹. The role of the epidermis is to maintain good barrier function. That is, to protect your body from bacteria and environment stressors caused by the sun and wind. It also helps keep moisture (water) in².

As we go about our day and sleep at night, the skin is constantly undergoing regeneration, but this process takes time. Skin cells of the epidermis take, on average, between 28 and 40 days in adults to regenerate³. The new skin cells begin in the stratum germinativum, which is the deepest layer of the epidermis³, and continue up to the surface. This process, which includes the production of keratinocytes in the deeper layer of the epidermis and their shedding as corneocytes (dead skin cells) from the surface of the skin, is known as the epidermal turnover⁴.

As we age, our skin undergoes many changes. Most notably, the epidermis thins out and our skin turnover rate slows significantly to 40 days and up to 60 days⁵ ⁶. This is one of the reasons why babies and young children have fresh, glowing skin – their skin turnover rate is much faster³.

How we can help encourage skin cell turnover

So what can we do? Well, exfoliation is one of the most important skincare steps for helping to promote radiance and increasing skin cell turnover. There are several ingredients that can help remove dead skin cells, visibly improve rough skin and promote cellular renewal, to reveal a more fresh, glowing complexion. 

Alpha-hydroxy acids (AHAs) include glycolic acid, lactic acid, malic acid, tartaric acid and citric acid. They help exfoliate the skin and remove dead skin cells, while helping with cellular renewal⁷. However, excessive exfoliation doesn’t equal a faster skin cell turnover rate. In fact, it can damage the skin’s barrier, leaving it red and inflamed, so be careful not to overdo it. 

AHAs can also visibly improve the firmness and elasticity of skin, helping to reduce fine lines and wrinkles⁸.