Facial Chemistry: Exfoliation Issue

As a skincare product category, exfoliators are part of the supplemental skincare routine. Our choice of exfoliation method and product will need to address the current state of our skin. That said, you should strongly consider your skin type as well as thickness of your skin in order to make all the right choices.

Reasons to exfoliate:

The process of cell regeneration slows down as we age. This essentially means that the body is slower to shed skin cells and generate new ones. If dead skin cells are not removed from the surface of the skin, the old skin cells start to pile up which causes clogging of pores and excess oil production. This in turn leads to acne, blemishes and overall dull and rough looking skin.

Proper exfoliation removes the barrier of dead skin cells clogging the skin and uncovers fresh new cells below. When done properly, exfoliation helps to open the way for treatment and moisturizing products to penetrate deep into the skin which makes them more effective.


Exfoliation methods:



What is it?

Exfoliants that use chemicals such as hydroxyl acids (lactic, glycolic, salicylic) and natural enzymes

Any abrasive material or substance that physically removes cells from the skin

How does it work?

Dissolve keratin protein or break apart the bonds between the skin cells

Exfoliating tool / scrub removes dead cells by creating friction between itself and the skin


Chemical exfoliants are less abrasive compared to mechanical ones


Overuse of acids might cause irritation or oily skin

Exfoliating “beads” are uneven in size so they can cause micro tears in the skin which makes it vulnerable to infections and scarring

Acid based solutions, exfoliating pads

Scrubs, skin brush

Starting out the research, I was convinced that mechanical exfoliation is “safer” for the skin. I was very unwilling to consider chemical exfoliation and I researched it only for comparison. Imagine my own surprise when I changed my mind entirely as I read more and more information. Now I made my alliances clear, I will focus this post on chemical exfoliation.

How does chemical exfoliation work?

There seems to be no conclusive information about the mechanism of chemical exfoliation; however, the most common theories of how they work are:

Normalizing cell turnover

Normalizing how quickly cells in the epidermis die and migrate to the stratum corneum, pushing old cells out. In other words, chemical exfoliants upregulate cell division

Unsticking cellular glue

Unsticking cellular glue that holds dead cells together in the stratum corneum

Please do keep in mind that chemical exfoliants are safe and gentle when properly handled and well formulated!!!!


Types of at – home chemical exfoliants:

Leave – on hydroxy acid products



Retinol / retinoid products

Base component(s):


AHA / BHA at higher concentration and power pH



Be aware:

It is rather arguable if retinol is part of exfoliating community but it is here since it does help with cellular turnover


Enzyme based exfoliants

Enzyme Exfoliator

What are enzymes?

Bio active components, most of which are extracted from fruits: papaya, pineapple, rice and pumpkin

How it works?

Enzymes are able to detach and digest dead protein which is exactly what dead skin cells are.

Enzymes cannot over exfoliate since they can digest only the “upper” layer – dead skin cells


–          Very gentle and very effective

–          Anti-inflamatory properties

–          Can be rinsed off completely


–          Enzymes are very unstable!!

If the temperature and pH level are not right, they will not work

They need to be stored in a cool and dark place

Suitable for:

All skin types

Good for sensitive skin that cannot tolerate AHA and BHA treatments. That said, there are PHA products for sensitive skin


Enzyme exfoliant formulations are suggested to be too unstable for now. The tricky part is that there is no way of knowing when / if the product went bad. As such, I would stick to acid based exfoliants at the moment


Retinol and Retinoids

As I mentioned above, retinol is not really an exfoliant; however, it does act as an antioxidant and increases cellular turnover which helps dead skin cells to detach. Retinol is essentially a form of Vitamin A which is available without prescription. Retinoids like tretioin, adapalene and tazaratene are more potent and require prescription.

Retinol products are notorious for causing dry skin as well as visible peeling and flaking due to irritation. As such, it is suggested that retinol products are used once or twice a week but some people use retinol / retinoids nightly.

Do remember to use plenty of calming ingredients and antioxidants in your skincare when using retinol products. Skin irritation contributes to premature aging so please exercise caution and pay attention to your skin’s reaction and needs.


Leave – on hydroxyl acid products

Hydroxy acids (PHA / AHA / BHA) are the most commonly used ingredients in chemical exfoliants. You can read more about hydroxyl acids as well as about how to choose and use them in the post I will reference at the end of this post.

The biggest issue with picking a hydroxyl acid product is pH:

–           If the pH is too high, the acid would not penetrate the skin at a higher concentration;

–          If pH is too low, you run a risk of irritation, chemical burns and long – lasting damage to the skin

There is also an issue with concentration of the acid in the product:

The general rule of thumb for leave – on hydroxy acids is:




Less than 4

Less than 3.5


4- 10%

1 – 2%


Superficial peels are essentially a controlled chemical burn that can improve acne, pigmentation and shallow wrinkles. Repeated treatments are usually needed in order to see significant improvements.

If you decide to use a peel, you should remember that chemical peels are not for the uninitiated skin!!! You should train your skin for a while with increasingly strong leave –on hydroxyl acid exfoliants before you proceed with a peel.

There are peels that you would apply for only a few itchy minutes and there are those that self-neutralize. You have to make sure that read, fully understand and follow the instructions of the products.


Few possible suggestions on frequency of use of chemical exfoliants:

  • There are people who use exfoliating acids on daily basis. My skin is fairly thin so such practice is not for me.
  • There are suggestions to use exfoliation minimum once a week and maximum twice in order to avoid the problem of clogged pores and buildup of dead skin cells. The idea here is that you should not exfoliate already inflamed skin. You should support your skin with maintenance exfoliation so it does not even go into the inflammation stage.
  • Do not use facial acids on daily basis! Research continues to show that when the skin is exfoliated daily, the inflammation created – even if it is not visible – can accelerate the aging process. For the best results, it is suggested that exfoliating acids are used 3 nights on and 3 nights off. For example, during the first 3 nights you could use products with exfoliating acids and follow up with 3 nights of hydration and antioxidant rich products. The idea behind such suggestion is that after 3 nights, when the skin is well exfoliated, use hydrating products to feed the “new” cells with nourishing performance ingredients like fermented ingredients and antioxidants.
If you have not yet had a chance to read, I would suggest looking into the posts about Exfoliation and Acid Mantle and Intro to pH Balance: Skin and Skin Care and Heroin of Cosmetology: Facial Acids.


Thanks for reading,


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