Board-certified dermatologist Jennifer Herrmann explains why: “Removing the outer layer of dead cells makes the skin look immediately brighter and more youthful, especially because as we age, our cell turnover slows and dead skin cells stay on our skin longer, leading to dullness. By removing the outermost dead cells, exfoliation also allows other active anti-aging ingredients like retinol and growth factors to more easily penetrate deeper skin layers where they are effective.”

According to Herrmann, there are two methods of exfoliation. “Mechanical exfoliation involves using a device or tool—think diamond tip microdermabrasion machines or scrubs with charcoal or gritty salt or sugar to manually remove dead skin cells. Chemical exfoliation uses light acids like salicylic or glycolic acid or enzymes like papaya to gently break down the glue between the outermost skin cells.”

Your skin type is the number one factor in considering which method to use. Sometimes scrubs can cause irritation, so, as Herrmann recommends, “For those with sensitive skin, chemical exfoliation is usually the way to go.”

There are several schools of thought on how to exfoliate your face, especially with regard to frequency. There is no simple answer for this—all is better left up to the instructions on the product you plan to use. Dermatologist Craig Kraffert, MD, explains further: “The ‘old school’ way of thinking was to not exfoliate more than a few times a week, but some types of exfoliant cleansers can be used every day (or even twice daily) and eliminate the need to use both a cleanser and an exfoliating treatment separately.”