Exfoliation - Chemical

Welcome to the forth in this mini-series about exfoliation. Today, we're going to look at chemical exfoliants - what they are and how they work, and we're going to learn how to do DIY chemical exfoliating.

You might be wondering why we're looking at delicious looking edibles while talking about chemical exfoliants. The reason is quite simple, as you shall shortly discover.

But first, let's have a super brief historical peek at chemical exfoliation.

It's as Old as The Hills

Chemical peeling is actually not at all new. The Egyptians have references to it as early as 1550 BC. I've tried to discover how it was used by them and in the period between 1550 BC and recent history, but information is exceedingly scarce.

Fast forward several hundred years:
The use of chemical substances to improve various skin conditions surfaced (again) in the 1800's where Austrian physician and dermatologist Ferdinande Hebra entered the scene. Hebra wrote the groundbreaking Atlas of Skin Diseases and helped set the stage for many modern dermatological practices. Among (many) other things, Hebra's medicated soaps were created to 'treat freckles and wash away tan'.

How Chemical Exfoliants Work

Chemical exfoliants work by dissolving the protein binder (or 'glue') of the skin cells which then allows these cells to be shed from the skin.

Using a chemical exfoliant might sound like the harshest thing you could possibly put on your skin, but chemical exfoliants can be quite effective without being harsh.

Acids For Skin

You've probably heard of alpha hydroxy acids (AHA's). Some of the most typical chemical exfoliants are AHA's. AHA's are naturally present in many fruits and foods such as apples, sugar cane, lemons, and limes.

AHA's can also be synthetically made. A quick look in your refrigerator will probably reveal a number of AHA-rich ingredients.

Here's a breakdown of some of the most common AHA's:

Glycolic acid

With excellent skin penetrability, glycolic acid is not only ideal for 'tickling' the cells and making them want to grow, it's also widely used. Natural sources are fruits such as pineapple, sugarcane, sugar beets and (unripe) grapes.

For cosmetic use, glycolic acid is created by nature identical methods (read: they 'copy' nature in a lab environment).

Glycolic acid has the smallest molecule size. It is the concentration of the acid and the pH that makes for its strong effect. A higher concentration will effectively remove a layer of skin. Depending on the pH level, glycolic acid can be a serious skin irritant. Dosed correctly, it's an effective exfoliant.

There are different production methods for this ingredient.  Some result in unwanted extras (such as formaldehyde). For cosmetics use, the purer the final product, the better.

Mandelic Acid

From the German word Mandel (which means almond), mandelic acid is indeed sourced from almonds. It is often combined with other AHA's for chemical exfoliation/peels.

Citric Acid

You've probably already guessed the source of this widely used AHA. Aside from functioning as a pH regulator in many cosmetics formulations, citric acid is also used in combination with other AHA's for various skin treatments.

Lactic Acid

There are many stories of Cleopatra bathing in milk to keep her skin beautiful. They could very well be true, because milk contains lactic acid – an effective chemical exfoliant. But Cleopatra probably wanted max effect out of her milk bath, so she probably the most lactic-acid-rich milk – donkey's milk.

The Plusses

Lactic acid is a natural part of the human body, so it isn't likely to cause allergic reactions. Using Lactic acid for chemical exfoliation helps hydrate the skin, helps stop bacteria production, and even slows down pigment accumulation.

Here's a list of the plusses lactic acid has to offer:

  • good for fighting hyperpigmentation
  • helps reduce fine lines and wrinkles
  • helps unclog pores
  • helps prevent blocked follicles
  • helps prevent age spots
  • helps for sun damage

And For Once, More Really is Better

Percentages matter: a study showed that applying 12% lactic acid twice daily over a period of 12 weeks made a measurable difference in thickness of the skin. Both epidermis and dermis showed improvement.

In the same study, another group used only 5% lactic acid and had less positive results. In this case, more was better. (link to study below)

The best lactic acid sources:

  • buttermilk 
  • sour cream
  • yoghurt

DIY Chemical Exfoliating Face Mask

Natural yoghurt is an effective, inexpensive and incredibly easy face mask. This is mask is mild enough to be done daily, yet effective enough to where you will see a noticeable difference with daily use.

Simply apply natural yoghurt to cleansed skin in a thick layer (or layer it up with many thin applications) and let it sit for as little or long as you please.

Here's a screengrab of a vine I did – checking the texture after half an hour. In this session, I let the yoghurt sit for an entire hour.

To remove: 

Pat dry
Mist an alcohol-free tonic
Finish with face oil or your regular moisturizer

On some days, I'll only have 5 minutes to do a yoghurt mask, but even 5 minutes is better than no minutes. And this method is so easy, quick, cheap, and effective, how can you not want to do it every day?


References, Links, and More Info

Dermatologic Surgery: History of Chemical Peeling
Cleveland Clinic Journal of Medicine: Cosmetic use of alpha hydroxy acids
International Dermail Institute: Glycolic vs lactic acid
Epidermal and dermal effects of topical lactic acid
Glycolic acid production (film by chemical company)
Complications of medium depth and deep chemical peels
Ferdinande Hebra (wikipedia)
Textbook of Bacteriology

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