If you have a pulse and/or an internet connection, you’ve undoubtedly heard of “exfoliation” before.  However, not all exfoliation is created equal and it’s easy to become overwhelmed (and supes confused) by the variety of options available. Moreover, it is important to note that while exfoliation can work wonders for your skin, if done incorrectly, it can cause more harm than good.  To help ease the process, I’m breaking down the two types of exfoliation and what you need to know about each so you can incorporate them into your skincare routine.

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Chemical Exfoliation

The word “chemical” gets a bad rap. We’re taught to avoid chemicals in most aspects of our lives—from the food we eat to the air we breathe—so, the last thing we would instinctively do is put chemicals on our face.  But when it comes to skincare, chemicals can work wonders and (as discussed in this post) can sometimes be better for your skin than their “natural” or “organic” counterparts.  Chemical exfoliants work by removing the dead cells on the surface of the skin either through loosening the “glue” that binds old cells to new ones or dissolving the old cells altogether.  In most cases, chemical exfoliation is actually more gentle on the skin than mechanical methods (more on that below).

Acids are the most common type of chemical exfoliation and since incorporating acid exfoliation into my daily routine (details on the products I love below!), I’ve noticed an unbelievable difference.  While there are a variety of acids that you can use, AHAs (alpha hydroxy acids) and BHAs (beta hydroxy acids) are the most widely-used.

 

Alpha Hydroxy Acids (AHAs)

AHAs encourage the shedding of old skin cells by loosening the bond that keeps the cells on the surface of the skin. By loosening that bond, old cells are able to fall away with greater ease.  AHAs primarily work on the skin’s surface (epidermis layer), but with continued, extended use or when administered by a dermatologist in higher concentrations, they can penetrate deeper into the skin.  The most common types of AHAs include Glycolic, Lactic, Tartaric, Citric, Malic and Mandelic Acids.

Because AHAs are water-soluble, it is important that your skin is cleansed and free of as much oil as possible before applying.  They are also best for normal to dry skin because of their humectant properties (ability to draw and hold moisture into the skin).  AHAs are best used at night as they can increase photosensitivity, which also makes it EXTREMELY important to wear SPF during the day (but you’re doing that already, right?).

Beta Hydroxy Acids (BHAs)

BHAs go a step further than AHAs and are excellent for those with acne or acne-prone skin. They also work on the epidermis of the skin, but they are oil soluble which makes them able to penetrate deep into the pore and clean out pore-clogging bacteria. In other words, BHAs clear the “gunk” build-up in a gentle, non-abrasive manner.  The most common type of BHA is salicylic acid, which also has antibacterial and anti-inflammatory properties, making it ideal for treating acne. Those with normal skin types can also benefit from BHAs but if you have dry skin, tread lightly as they can increase dryness and lead to irritation.

Polyhydroxy Acids (PHAs)

Like the other acids, PHAs loosen the “glue” that keeps the old, dead cells attached to the skin. However, PHAs have a larger molecular structure than the other acids, which makes them unable to penetrate past the uppermost layer of the skin. This results in gentle exfoliation with little to no irritation. If your skin is more sensitive, PHAs might be the best chemical exfoliator for you.

Enzymes

Enzymes, or more specifically, proteolytic enzymes, are another type of chemical exfoliant but instead of just weakening the bonds of the cells, these enzymes digest (break down) the proteins within the cell.  The most common types are papain (an enzyme found in papaya) and bromelain (an enzyme found in pineapple). Proteolytic enzymes are activated by water and not dependent on the skin’s PH level like some acids. The level of exfoliation that can be achieved with these enzymes is also limited, which can make them a great and natural choice for gentle exfoliation.

It’s important to note that Retinols and Retinoids (Vitamin A products) also act as chemical exfoliants by promoting cell turn-over, but we’ll cover that in another post.  The four chemical exfoliants detailed above are the most common types that you need to know about. There are endless products that include one or multiple of these chemical exfoliants, and it’s important to make a decision based on your own skin type and sensitivities.  Personally, I use and LOVE the Biologique Recherche P50 every single day and it has made an insane difference in my skin.  Other favorite acid exfoliants include Paula’s Choice Skin Perfecting Salicylic Acid Exfoliant, The Ordinary Glycolic Acid Toning Solution and Dr. Dennis Gross Alpha Beta Universal Daily Peel.

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Mechanical Exfoliation

Mechanical or physical exfoliation refers to the use of abrasive materials (i.e. facial brushes, rough sponges, microdermabrasion, dermaplaning, etc.) or substances (i.e. cleansing products with scrubbing beads) that physically remove dead skin cells.  Despite how pervasive these tools and scrubs are, they are widely controversial among dermatologists because they often do more harm than good. You can achieve the same (or superior) level of exfoliation with gentle acids (chemical exfoliation described above) rather than tools or products that tug and tear at the delicate skin on your face, often causing it to sag and age prematurely.

So, despite what many skincare marketers might lead you to believe, you should tread lightly and mechanically exfoliate infrequently.  As discussed here, you never want to be scrubbing so hard that you’re left red, raw or in pain.  For me, a longtime favorite tool for mechanical exfoliation is the Clarisonic brush which comes with a variety of different heads for every skin type.  However, I only use this device once a week. Similarly, I seldom use harsh scrubs of any kind anymore and when I do, it’s only once or twice (max) a week.  

As always, it’s important for me to note that I am not a dermatologist or a trained medical professional. The information shared in my Skincare Memos is based upon extensive research, reading scientific reports and interviewing board-certified dermatologists, but you should always consult a doctor prior to beginning any new skin regimen.