Guide to chemical exfoliants: What are they, how to use them and how much is too much?
Smooth and silky
Alright, skincare enthusiasts—today we’re talking exfoliants. Specifically, exfoliants of the chemical kind. An often misused and intimidating ingredient, we’ve taken the opportunity to show you how to make the most of them, maximising their benefits and troubleshooting some common issues.
From how often to use them, to the best chemical exfoliant for each skin type, this tell-all guide is your one-stop shop for any and all of your burning questions.
What are chemical exfoliants?
There are three types: AHAs, BHAs and PHAs (we’re not getting into enzymes...yet).
Alpha Hydroxy Acids are tiny water-soluble molecules that are able to dissolve the intercellular glue holding your superficial skin cells together, which thus promotes your skin’s natural shedding process. In addition, they also stimulate collagen production in the skin to improve skin elasticity and moisture content.
As they are lipophobic (oil-repellent), their action is mainly focused on the surface of the skin, so they do not penetrate as deeply as BHAs do.
In addition, they can improve the moisture content of your skin, which makes them perfect for an array of skin types (we’ll get to that later). They are also derived from natural sources; here are a few AHAs you may be familiar with:
|Glycolic acid||Sugar cane|
|Mandelic acid||Bitter almonds|
|Malic acid||Apples and pears|
|Citric acid||Citrus fruits|
Note: Citric acid and malic acid can behave like either AHAs or a BHAs, depending on how it is formulated. However, they act as AHAs more often.
Beta Hydroxy Acids are oil-soluble, meaning that they penetrate deeper into your skin as they can get through the sebaceous oil in clogged pores. They act to gently push out dead skin, bacteria, sebum and other pore-clogging debris. In addition, they also have many anti-inflammatory and anti-bacterial properties, which makes them suited for an array of particular skin types.
You’re probably familiar with one particular BHA: Salicylic acid. It’s one of the most ubiquitous ingredients, found in all types of spot creams, toners and other cosmetics.
Much lesser-known, but also the most gentle of all chemical exfoliants, Polyhydroxy Acids are the holy grail for more sensitive skin types (including conditions such as eczema or rosacea). They work in the same way as AHAs do, only slower and less penetrating (because their molecules are larger). PHAs, like AHAs, are humectants, so they attract moisture to improve skin hydration.
Like BHAs, they also have anti-bacterial and anti-inflammatory properties. Some examples of PHAs that you may have encountered are gluconolactone, galactose and lactobionic acid.
Why do I need to exfoliate?
Exfoliation (when done right) is a great way to restore skin health by promoting cell turnover and blood flow. Plus, removing that layer of dead skin cells improves the absorption of the rest of your beauty products by your skin.
Your skin is made up of many, many layers; and the outermost of it is called the Stratum corneum of the epidermis. It is a resilient layer of keratinised cells that shed regularly to balance out skin cell production. It has a bunch of physiological functions, including protecting the underlying tissue from dehydration and infection. Its thickness varies throughout the body, with the thickest areas being on the feet and hands (naturally) and the thinnest being in areas such as the face.
Fun fact: when your skin looks dull, it’s because your Stratum corneum has thickened too much, warranting a much-needed exfoliation session.
Which one should I use?
It all comes down to your skin type—ahead, here's a very general guide to finding the right kind of exfoliant for your skin.
Oily, Acne-Prone Skin
Salicylic acid (BHAs) are the best option for oily and acne-prone skin as it target clogged pores and has anti-inflammatory effects. Further, they reduce oil production which is ideal for oily skin (if you're not oily, just make sure to follow up with a good moisturiser!)
Believe it or not, some acids actually have wonderful hydrating properties, such as glycolic and malic acid. Further, they can exfoliate dead skin cells and brighten dull skin.
As we mentioned PHAs are best suited for those with sensitive skin thanks to their humectant properties.
Good news! With normal to combination skin, the world is your oyster! Go forth and play with any kind of formulation, because chances are that your skin can handle it.
Obviously, this isn't a one-size-fits-all science, so definitely shop around and experiment with different formulations. Plus, keep in mind that a lot of chemical exfoliants on the market are blends of more than one acid; for example, Dr Dennis Gross' Alpha Beta Extra Strength Daily Peel incorporates a blend of AHAs and BHAs into its formulation. The key is to scan the ingredients list before you invest in a product and make sure that it suits your skin!
Is there anything I shouldn’t use with my chemical exfoliants?
It’s always imperative to check the ingredients in your skincare products! Look out for retinoids, vitamin C and benzoyl peroxide as these can all interact badly with your chemical exfoliants.
Why do I need SPF?
It's true—there has been no evidence (so far) to suggest that BHAs like salicylic acid have any photosensitisation effects on skin after use. Interestingly, it was actually shown to have protective effects on the skin from UVB rays. In fact, some derivatives of salicylic acid such as octyl salicylate are common ingredients in sunscreen, that help to absorb UV light and prevent skin damage.
That said, with AHAs, it's a different story. Think about it this way: you’re putting a product on your skin that essentially strips your skin of it’s topmost protective layer. Yes, it doesn’t get rid of the whole layer (otherwise, ouch) but studies (of which there are a very limited number, to be fair) have shown that AHAs increased skin photosensitivity. Specifically, the results found that UV exposure 24 hours after AHA application caused symptoms of increased redness, DNA damage and sunburn cell production in human skin.
Either way, regardless of whether you're using chemical exfoliants or not, it's always a good idea to stay on the safe side and layer up on the sunscreen–especially in Malaysia’s eternal summer.
How much is too much?
As good as silky smooth skin can feel post-treatment, it's easy to get carried away and go overboard. Yes, over-exfoliation is a real thing. You’ll know that you’ve gone a little bit too far when you start experiencing a few of these things:
- Redness and irritation
- Dryness and flakiness
- Shiny, thinning skin
- Increased breakouts
- Increased oil production
At this point, you’re going to want to cut way, way back on the exfoliation, and focus more on hydration. Also, skip the foaming cleansers—your already dehydrated skin doesn’t need anything else sucking the moisture out of it. Instead, opt for cleansing lotions, which are far more gentle on the skin, and opt for moisturisers that are fragrance-free and alcohol-free.
You can introduce exfoliation back into your routine again once your skin is recovered; just make sure that you’re doing so gradually, sticking to once every fortnight and slowly increasing the frequency to three times a week at most.
So, there you have it! All your questions about chemical exfoliants: answered.