Chemical vs Physical Exfoliation.
You may, or may not, have heard these two different terms being thrown around in the skincare world. Chemical exfoliation, and physical exfoliation. While the first option sounds rather harsh, it can actually be the gentler of the two options
So, what is the difference between chemical and physical exfoliation?
What is physical exfoliation?
Physical exfoliation is with the use of small grains, a brush, or a scalpel. But not all physical exfoliants are created equally. You will generally notice if a product contains a physically exfoliating ingredient as it will feel gritty and rough on your skin. Most commonly, these ingredients are ground down natural products such as nuts, stones, plants and plant extracts. There was a time when companies the world over used little plastic beads called micro beads. Thankfully due to their awful impact on the environment they have been banned in some countries, a trend that is on the rise.
But don’t go too hard! When you scrub skin with abrasive scrubs, they can put micro-tears into skin. Micro-tears are created by agents that are too sharp or jagged, causing little tears in the skin. Many dermatologists are not fans of physical exfoliants because of how they can result in micro-tears. They make your skin more vulnerable to environmental damage, pollution, and sun damage. The length of time the person scrubs and the amount of pressure applied while scrubbing are two variables that can lead to irritated skin. There’s also the matter of the granules, or the specific grains that make up different scrubs. Large, hard, and sandlike rocks, like the ones in St. Ives’s Apricot Scrub, are the most damaging because they are too abrasive for the face’s thin skin. Part of the reason scrubs may be so popular, despite their insidious long-term effects, is that they’re cheap and the repercussions aren’t noticeable until years, even decades later.
What is chemical exfoliation?
Don't be scared by the idea of putting acids on your face! Chemical exfoliators include low-percentages of gentle acids and enzymes. These ingredients dissolve the glue that hold dead skin cells in place, helping our skin to speed up it’s cell turnover to reveal fresh, dewy, healthy looking skin. Chemical exfoliators come in the form of cleansers, toners, serums and sometimes even moisturizers. Be careful mixing targeted topical treatments that may already be harsh, which could lead to flaking, redness and irritation. Best to consult your dermal therapist or doing your research before purchasing. Chemical exfoliators are a great option for people with sensitive skin, because you can’t really over-scrub. No harsh bits, no over-scrubbing!
Chemical exfoliants like AHAs and BHAs are universally preferred by skin-care experts. Like scrubs, they gently encourage skin-cell turnover, but unlike scrubs, they’re generally very expensive.
What are AHAs and BHAs?
AHA's (Alpha Hydroxy Acids) are a class of chemical compounds derived from natural substances. They occur naturally in fruits, milk, and sugar cane. Although they are called acids they are not to be confused with strong industrial acids such as hydrochloric acid and sulphuric acid. These are best for sensitive and dry skin. AHA’s are a bit more of an all-rounder.
- Glycolic. The most common of all the AHAs, this acid has the smallest molecular structure, which allows it to be the most effectual on the skin but also the most potentially irritating. I recommend looking for it in low concentrations if you are new to AHA products -- 8-10%. Alpha Hydrox is a commonly recommended line of glycolic acid products. Has a mild humectant property.
- Lactic. The second most common of all the AHAs. This is the basis for the beloved St. Ives pads. The molecular structure is larger than AHA but not as large as mandelic. It is highly recommended for sensitive skin types, such as rosacean skin. Lactic acid is also milk derived. It has great humectant properties.
- Mandelic. The least common, but one of the best choices for acne-prones. It has a large molecular structure, meaning it takes longer to work its magic on skin and is thus less irritating. It is also anti-bacterial/anti-microbial. It is derived from bitter almonds. Mandelic also has moderate humectant properties.
BHA's (Beta Hydroxy Acids) are oil-soluble molecules and can get a deeper clean. One of the more popular is Salicylic Acid. It breaks up the cells in the lining of the pores, which helps declog blackheads. This would be better for oilier skin and acne prone skin types.
Salicylic acid is derived from salicin. Because of this, it is not advised to use salicylic acid products if you have an asprin allergy.
Salicylic acid has no humectant properties, and in fact usually causes drying of the skin, though it is usually more gentle than other common acne treatments, such as benzoyl peroxide
So, yes, to some degree, scrubs cause cosmetic damage. The severity of that damage wholly depends on how well your skin is able to repair itself, the kind of scrubs used, and the frequency and intensity of use. Despite their intimidating name, chemical peels are, in fact, less damaging.