Updated: Mar 9
Exfoliants are meant to help remove the accumulation of superficial skin cells, keratin, and sebum from the skin. Read more...
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What is an exfoliant?
When I discuss exfoliants I find it best to first take a step back and understand what an exfoliant actually is to better understand the different types and the role they can play in your skincare routine.
Our skin is dynamic- it is constantly renewing itself. During this renewal process, "dead skin cells", sebum or oil, and keratin, a protein from our skin, are accumulating at the surface. These naturally will shed or exfoliate on their own. However, it has been shown that sometimes they will linger and sometimes accumulate in our pores or on the surface of our skin. This can result in the potential for acne or just a ‘dull’ overall appearance of the skin.
Exfoliants are meant to help remove the accumulation of superficial skin cells, keratin, and sebum from the skin to give the skin a ‘glow’ by revealing the skin hiding behind this layer.
What types of exfoliants are there?
There are two types of exfoliants: physical and chemical.
What is a physical exfoliant?
Physical exfoliants are products that work by manually removing the excess by the abrasive or gritty quality. This can be through the addition of granules, sugar, seeds, or nutshells to a cleanser or devices such as loofahs or brushes. The goal is to help shed or remove the buildup on our skin directly.
What is a chemical exfoliant and how does it differ from a physical one?
Chemical exfoliants are products that use ingredients such as alpha hydroxy acids, beta hydroxy acids, or enzymes to dissolve the fats or lipids in the superficial layers of skin to help shed these cells and the by-products of these cells such as keratin and sebum or oil. The process does not involve abrasive substances or manually abrading the surface making it potentially less traumatic to the skin.
Which skin types should use a physical exfoliant and why?
If you have oily or dull-appearing skin then manual exfoliation may be a better way to go. I realize there are a lot of devices and loofahs and skin brushes on the market I’m not a fan of tools. The amount of bacteria that have been shown to build up in loofah sponges alone in studies is enough proof that these may not be a great idea- unless you are meticulous about constantly cleaning these in a bleach solution. I have had cases where patients have been so aggressive with facial scrubbing brushes and mechanical devices that they actually developed impetigo (an infection with staph bacteria) as a result. To get a simple wash, just use your hands. After all, once you have soap and water on them- they are clean! If you would like to use a gentle exfoliative then stick with ones that wash down the drain and are not reused. Sugar scrubs, apricot scrubs, etc. all work well for this purpose.
Loofahs have been shown to grow Pseudomonas, Klebsiella, Enterococcus, Staphylococcus, and more. If you couple the fact that the bacteria are trapped in the fibers of the loofah and that these sponges are used to exfoliate the skin, the risk of infection is much higher.
Towels are considered to be a fomite that can transmit disease as well. Not only can they hold bacteria, but viruses are also known to be transmitted by contact as well. Molluscum is a type of virus that can cause small papules on the skin and last for over a year in some cases. Its spread amongst families has sometimes been linked to shared towel use.
Our hands can be easily cleaned. I recommend avoiding devices for our skin as the ability to effectively clean these after each use is limited. If you are seeking some exfoliation that these can provide, try using scrubs that rinse down the drain. Sugar scrubs, apricot scrubs, or any kind of gritty cleanser can achieve the same results. The benefit is that these are not reused as they rinse down the drain!
Which skin types should use a chemical exfoliant and why?
Choosing an exfoliant that’s right for you really depends on your skin type and the outcome you are hoping to achieve. If you have an underlying issue with your skin that you are actively trying to treat or address then chemical exfoliants will likely serve you best. Acne and anti-aging regimens tend to be best suited for this category.
Which ingredients should one look for in a physical and chemical exfoliant?
Physical exfoliants are products that work by manually removing the excess by the abrasive or gritty quality. This can be through the addition of granules, sugar, seeds, or nutshells to a cleanser or devices such as loofahs or brushes.
Sugar scrubs. I personally am a big fan of sugar scrubs for multiple reasons. I will put them in the physical exfoliant category simply because the gritty texture of sugar before it dissolves allows us to manually remove dead skin cells and oil. What is nice about sugar scrubs is that they do not tend to be too harsh or abrasive in their quality and dissolve nicely. I find some of my patients get aggressive with scrubs. I have seen dyspigmentation in the pattern of a scrubbing technique. It's hard to go overboard with sugar because it naturally dissolves and the abrasive quality goes with it. The added bonus that most people do not realize is that glycolic acid, an alpha hydroxy acid or chemical exfoliant, is also derived from sugar! There is an added bonus of a little chemical exfoliation in this process. Lastly, sugar does tend to hold onto moisture and hydrate as it exfoliates.
Granules. Many products use rough granules to achieve exfoliation. Common products include crushed walnut shells, almonds, barley meal, bean powder, etc. These physical exfoliants work by manually exfoliating. The granules tend to maintain their shape and not dissolve easily. These products have a niche and can provide a nice ‘buffed’ look that is great before putting on makeup or if you just feel like you have added buildup on your skin and need to get a little more aggressive. I caution against using these days because once you have physically removed every last trace of a dead skin cell or oil, chances are it will take a few days to come back! If you scrub this aggressively day to day chances are you will start to abrade your own skin underneath and feel pain, burning, stinging, or rawness. Also, I caution people using acne products should avoid these scrubs. Acne products tend to contain alpha and beta hydroxy acids. You are already getting a chemical exfoliant. Coupling this with a physical exfoliant will be very very uncomfortable.
Devices. I caution against the use of brushes or devices to achieve manual exfoliation. If you are aggressive about cleaning your device after every use then it's possible these will work for you. I do not recommend them on acne–prone skin. They will aggravate and worsen the appearance of acne. I routinely see cases of impetigo, discoloration, and severe irritation. These devices give people the impression that they are ‘buffing’ out wrinkles in their skin like buffing out scratches on a car. It doesn’t work that way.
Chemical exfoliants are products that use ingredients such as alpha hydroxyl acids, beta hydroxyl acids, or enzymes to dissolve the fats or lipids in the superficial layers of skin to help shed these cells or by-products of these cells such as keratin and sebum or oil.
Alpha hydroxy acids such as glycolic acid, citric acid, and lactic acid break apart superficial skin cells by breaking apart the adhesions that hold them together. They are found in higher concentrations in chemical peels meant to treat acne, discoloration, and aging. In lower concentrations, they will often be seen in cleansers and topicals. These can be a bit aggressive depending on the concentration of a product.
Beta hydroxy acids such as salicylic acid are milder than alpha hydroxy acids but work in a similar way. Salicylic acid is a common ingredient in acne washes and spot treatments. It can also be found in moisturizers or creams for psoriasis to help shed or peel excess flaking or dryness of the skin.
Enzymes are even milder and are essentially fruit extracts such as papaya that are known to help exfoliate but not too aggressively. I often apply these after microdermabrasion to further assist in exfoliation afterward but are not too effective alone. If you have very sensitive skin, however, this is a good option to play with.
What are some best practices for using a physical exfoliant?
Physical exfoliants are best used when needed, but not more often than once a week or every other week. These can be harsh for many skin types so they should be used with caution. Also, our skin has an interesting tendency to “thicken” in response to excess friction – perhaps an attempt to protect itself. This tendency is called lichen simplex chronicus. Thickening and discoloration of the skin with accentuation of the skin marking lines can happen after repetitive friction or trauma to the skin. Psychologically, I see so many instances of people sincerely feeling as though they are ‘scrubbing’ their acne away or ‘buffing’ out their wrinkles. I think it's important to know what can happen if you find yourself in this position! If you do plan to use a device, it is important to clean this after every use with a bleach solution.
What are some best practices for using a chemical exfoliant?
Chemical exfoliants come in a number of varying strengths. I find it best to start with an enzyme exfoliant or beta hydroxy acid such as salicylic acid and then increase the strength gradually as your skin can tolerate the alpha hydroxy acids. The plant-based enzyme exfoliants work well and are relatively mild.
If your underlying concern is acne, then consider beta hydroxy acid-based exfoliants since these tend to be well tolerated. Be careful to avoid using too many different versions of exfoliants at the same time. I often find my acne patients are using a salicylic acid cleanser, a retinoid, and a scrub all at the same time. They are wondering why their skin is so red, raw, and sensitive all the time. I even find at some point people are more bothered by the redness than the acne itself! Looking at a regimen like this, there are 2 chemical exfoliants and a physical exfoliant being used simultaneously. Some people need this and some people can tolerate it. Not everyone can get away with a combo like this!
Look at your products, the ingredients, and the claims. If there are too many products focused on exfoliation as their primary mechanism of action, it is worth substituting one for an acne product that treats acne with a different approach to get the best results. Examples of these include anti-inflammatory topicals that have anti-acne properties such as rosewater-based products, azelaic acid (this is not an alpha hydroxy or beta hydroxy acid, it’s a dicarboxylic acid. It has antibacterial and anti-inflammatory properties. Its made by a natural yeast on our skin), topical antibiotics or oral medications with the help of your dermatologist.