We’ve all been told about the importance of exfoliation since the days when St. Ives Apricot Scrub was all the rage (a truly age-revealing reference). The perception has always been that you can scrub your way to glowing, baby-soft skin. But physical exfoliation isn’t the only (and sometimes not really the best) way to effectively slough off dead cells and keep skin turnover healthy.
Meet the chemical exfoliants: ingredients that weaken the chemical bonds holding those stubborn, overly attached dead cells and return skin to its smooth, glowing self. Here, we’ll cover the entire exfoliation landscape, and how to rein in chemical exfoliants for your skin’s “Aha!” moment.
Why Should You Exfoliate?
In order for skin to stay healthy and look youthful, it has to constantly shed. But as we get older, this cell-turnover process can start slowing down, leading to dull, rough skin. This is where chemical exfoliants come in to help kick out those old cells that have overstayed their welcome.
Desquamation is the process of fresh skin cells moving up and old cells shedding. This is essentially your skin’s turnover rate. In healthy stratum corneum, the cell-turnover cycle is about two to three weeks. Your entire epidermis turns over in about seven weeks!
Skin’s turnover rate is crucial to its health. Desquamation can slow down due to aging, environmental stressors, and dehydration. When this turnover process slows down, it starts a crappy, vicious cycle of rough texture compromised barrier function dehydration further cell-turnover slowdown. Meaning, your skin becomes rough, scaly, and dull. Eek!
This is where chemical exfoliants come in! Chemical means they are acids that weaken the bonds (proteins called corneodesmosomes, should this ever come up at trivia night) between dead cells that have overstayed their welcome, which helps your skin return to a healthy turnover rate. Shedding the top layer of cells has the short-term benefit of smoothing skin texture. In the long run, some of these ingredients can even help tackle pigmentation, acne, and even—gasp— collagen production! Intriguing, yes? So let’s figure out which one is right for you.
What To Expect From Chemical Exfoliation?
There are three types of chemical exfoliants, all mild acids. They’re divided by their molecular structures, but we’ll save you from this chemistry snoozefest. The good thing is that these categories can also be characterized by their function.
Chemical exfoliants will help slough off those stubborn, past-due skin cells and kick your cell turnover into gear. One cool thing about these ingredients is that they can bring the almost immediate benefit of smoother skin texture. And that’s not to mention all the long-term benefits, like helping with pigmentation and acne! So, let’s take a look at the options.
Alpha Hydroxy Acids (AHAs)
The AHA category includes glycolic, lactic, mandelic, malic, and tartaric acids. These are water-soluble, weak acids. Of these acids, we’ll only focus on three: glycolic, lactic, and mandelic. The main difference between these three is their molecular size, which can help you choose which one to be your AHA soulmate. These have quite a long history of proven skin benefits for pigmentation, collagen production, and fine lines and wrinkles.
Beta Hydroxy Acid (BHA)
Really, the only chemical exfoliant in this category is salicylic acid, which has the unique characteristic of being slightly oil soluble. This unique trait allows salicylic acid to exfoliate down to the pore level. Add in the fact that it’s also an antimicrobial and anti-inflammatory ingredient, and you’ve got an ideal candidate for inflamed, acne-prone, oily skin
Gentle Polyhydroxy Acid (PHA)
Who dat? Yep, polyhydroxy acids are the new kid on the block. PHA typically refers to two molecules: lactobionic acid and gluconolactone, with gluconolactone being the much more common one in skincare. It’s said to be an ultragentle chemical exfoliation experience, and even acts as a humectant, keeping hold of water and hydrating skin. In fact, it’s so gentle that it doesn’t even make your skin sun sensitive, unlike the others. (Okay—seriously, though, let’s still play it safe and wear that sunscreen!)
There’s even data on gluconolactone’s potential to treat acne, and there will be more data to come. All in all, this is an ideal candidate for those who struggle with dry skin, sensitive skin or just haven’t had a lot of luck with the other exfoliants.
What To Expect From Physical Exfoliants?
Chemical exfoliants loosen up dead skin for that smooth, smooth glow. But as you age, your skin can get stubborn and refuse to let go of those old corneocytes, even with chemical exfoliation. Use a gentle physical exfoliant to mechanically buff those loose skin cells off.
Something as gentle as a soft, bristled cleansing brush or konjac sponge works great. Say no to 50-grit, sandpaper-worthy, apricot-seed or walnut-seed scrubs. It doesn’t have to be that way anymore!
Enzyme peels typically use bromelain, an enzyme found in pineapples, or papain, from papayas, instead of AHAs, BHAs, or PHAs. Enthusiasts say they get all the efficacy of the chemical products with none of the irritation.
There’s a study out there that claims 1% papain is superior to 5% lactic acid. We even found one claiming that roe extract (yes, you heard that correctly—fish eggs) is better tolerated and more effective than 4% glycolic acid. These studies are few and far between, so most of the “data” behind enzyme peels comes from manufacturers and product marketing. But, if your skin enjoys a glycolic peel, there’s no need to ditch it for salmon-egg essence.
Gommage, or gel, peels were all the rage in the early 2000s. Remember those overly enthusiastic mall-kiosk workers rubbing a miracle gel onto your skin to produce gross little balls of “dead skin cells”?
While some gommage peels do have low levels of AHAs, they are actually primarily physical exfoliants. The little balls are thickening fibers (usually cellulose) that help roll off loose dead skin in the most gentle way. As far as physical exfoliants go, this is as gentle as it gets. (Read: So gentle that they’re not super effective.)
How To Choose Exfoliants?
When it comes to choosing your acids, size matters. The smaller the molecule, the more aggressive yet effective. But if you’ve never used chemical exfoliants before, jumping right into that 30% glycolic peel is like trying to unicycle before you’ve taken the training wheels off your bicycle.
Chemical exfoliants are super popular, and you can find them in all sorts of products. They are most commonly found in cleansers, toners, serums, creams, wipes, and masks. Wait—that covers just about every product type out there! Right off the bat, we wouldn’t recommend incorporating acids through your cleansers. Just not the most effective way of getting that chemical exfoliating power. For all the other product types, there are three things you need to consider:
Concentration: Ah, yes! Like a broken record, we’ve hit our favorite Chemists’ Commandment again: Make sure you’re hitting those percentages. And for AHAs, these concentrations are pretty high. In fact, concentration is so key here that if you find products that don’t disclose the concentration of acids, just walk away. It ain’t worth the time.
The product’s pH: For AHA/PHA products, the lower the pH, the better it works. But of course, it shouldn’t just be as low as can be. There’s a balance between “good efficacy” and “Holy hell it burnnns!” For most people, there’s little chance of irritation if the pH is around 3.5, and you still reap the exfoliation benefits.
Support ingredients: Of course, every great formula needs a great supporting cast to really shine! Here are two ingredients you’ll want to look for:
- pH adjusters: These ingredients—which include sodium hydroxide, potassium hydroxide, and triethanolamine, among others—are crucial. Without them, your AHA pH can be really low. I’m talking a pH of 1 or even lower. So, if a product doesn’t use any adjuster, that’s pretty sketchy. Our advice? Don’t walk, run! Leave those products for dermatologists and aestheticians to use.
- Soothing ingredients: Some products include “soothers” to mitigate skin reactions and make your AHA experience more enjoyable. If you want to add some soothing assistance, look for ingredients such as bisabolol (German chamomile extract), calendula, and Centella asiatica.
How Do I Incorporate Exfoliation into My Routine?
Now you’re ready for your skin’s AHA moment! (Teehee.) Here are just a few Chemists’ guidelines for your exfoliation journey:
Apply in the right order: Chemical exfoliant acids are usually in heavily water-based formulas. That means that your AHA wipe, toner, or serum (pick one!) should fall into either step 1 or 2 of your nighttime routine, right after cleansing. Products with a concentration of under 10% AHA can be used daily. If you’re sensitive to even a lower concentration, use it on alternate nights.
Consider a high-concentration mask: A great way to elevate your exfoliant game is to add a high-level (20% or more) product to your skincare arsenal. These higher-concentration AHA products should be used as rinse-off masks no more than once a week.
Certain products you may already have can enhance your chemical exfoliation routine. The big three are listed below:
Clay masks and alcoholic toners: Since these products remove excess oil from your face, they can be ideal before your acid product. Excess oil and grime can prevent these acids from penetrating, so by using a clay mask or toner beforehand, you can boost your AHA efficacy without having to reach for a higher concentration. Just don’t leave the clay mask on for too long; a good five to ten minutes is all you need.
Petrolatum and balms: If you have a dry patch, a small cut, or just a slightly sensitive area, you can use petrolatum or a balm on those trouble spots before applying your treatment. That way, the acid won’t reach those sensitive patches.
Sunscreen: Last but not least . . . remember sunscreen! Most of these acids can make your skin more susceptible to sun damage. Of course, whether or not you’re using chemical exfoliants, you should always practice good sunscreen habits anyway.
What works best for my skin type?
The right exfoliation technique will minimize your chances of irritation and help you achieve the best results.
The skin of a normal person is clear and not easily irritated. Those with “normal” skin can try any exfoliating technique or product without experiencing adverse effects. Personal preference ultimately determines what works for you.
Shiny and greasy skin is a sign of oily skin. Oily skin types often benefit from stronger chemical and physical exfoliators, such as motorized brushes. Additionally, you can make your own scrubs or buy store-bought ones.
Flaky, rough skin is a sign of dry skin. Your moisturizer will be able to hydrate your new skin cells more effectively if you use an AHA such as glycolic acid.
Skin that stings or is otherwise irritated after using new products is considered sensitive. Chemical and physical exfoliants are typically more irritating than BHAs.
Combination skin consists of oily and dry sections. Each area should be treated individually, and products should be alternated as necessary.
An oily area may need a chemical exfoliator or scrub one day, and a dry area may need a low-level AHA the next.
Try products that contain retinoids, salicylic acid, or glycolic acid if you’re prone to breakouts.
Chemical Exfoliant FAQs
Q: This got really complicated! So, where should I start?
A: A good general starting point is 5% glycolic acid.
Q: What does a chemical burn do to your skin, anyway?
A: It’ll feel a lot like a sunburn—red, stinging, itchy, just all-around irritated skin. In more serious cases, you end up with discolored, rough-textured skin.
Q: If you had to pick just one to always use, would it be physical exfoliation or chemical exfoliation?
A: Go chemical. These ingredients not only buff the stubborn cells on the surface but also come with extra benefits to brighten skin and reduce fine lines and wrinkles
Q: So, if they’re acids, how come they eat away at the bonds attached to cells that need to go, rather than cells that should still be there?
A: Great question! In a nutshell, they don’t penetrate deep enough to eat away at the bonds that are supposed to be there. And this is how you over-exfoliate too. If you go too crazy on your chemical exfoliants, they will get to the cells that are supposed to be there. That’s how you end up with irritated skin.
Q: Is there such thing as too much chemical exfoliation?
A: Of course! Some signs of going too far are flaking, prolonged stinging, and redness.