Powder Cleanser and Exfoliant Review: Dermalogica, Farmacy, Alpha-H, Ella Bache, Ausceuticals

Powder Cleanser and Exfoliant Review: Dermalogica, Farmacy, Alpha-H, Ella Bache, Ausceuticals

Here’s a skincare trend I’ve been really getting into: dry powder products. These are cleansers and scrubs that come in a jar. You shake them out, mix with water, and you get a cleanser or exfoliant. They’ve been around for a while, and hark back to ancient times when people would mix up their own cosmetics from ground pigment (I’ve …

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How to Exfoliate 2: All About Chemical Exfoliants

aha-exfoliants

Here’s Part 2 of this skincare series on exfoliation. Part 1 was on physical exfoliating tools and scrubs, this time we’re tackling the more complex chemical exfoliants, before moving onto picking the right exfoliation routine for your skin in Part 3. For a simpler overview, you can head to this exfoliation basics post, and for a more user-friendly version check out my free exfoliation guide.

What’s exfoliation again?

Your skin is covered in a thin protective layer of dead cells (the stratum corneum) which naturally shed over time in a process called desquamation. Sometimes this layer gets too thick, resulting in dull, rough skin. Exfoliants help the shedding along, resulting in more even, “glowier” skin.

What’s chemical exfoliation?

Chemical exfoliants help cells shed in a more indirect way than physical exfoliation, which works using friction between the tool or scrub and the skin. The mechanism of how chemical exfoliants work aren’t always obvious, but the most common theories and methods of how they work are:

  • by normalising cell turnover – that is, how quickly cells in the epidermis die and migrate to the stratum corneum, pushing old cells out. Exfoliants do this by travelling to living cells under the dead layer and telling them to change how they behave – in more technical terms, they act on receptors to upregulate cell division. (Technically, any ingredient that does this is a drug, but regulations around these “cosmeceuticals” is pretty iffy.)
  • by unsticking the cellular glue (desmosomes) holding dead cells together in the stratum corneum.

Chemical exfoliation is touted to be gentler than physical exfoliation, mostly because it’s less prone to user error. However, how well it works depends largely on the formulation of the product. A poorly formulated product might not work, or it might work so well that it irritates your skin and causes uneven pigmentation and chemical burns.

Product categories

Click on each heading to jump to that section.

Leave-on Hydroxy Acid Products

Hydroxy acids are the most common ingredients in chemical exfoliants. There are two main types:

  • Alpha hydroxy acids (AHAs), which includes ingredients like glycolic acid, lactic acid, malic acid and mandelic acid. Glycolic and lactic acids are most common in skincare, and the vast majority of scientific studies on AHAs are based on the action of glycolic acid.
  • Beta hydroxy acids (BHAs), of which salicylic acid is the only one commonly used in skincare (I’ll be using the terms “BHA” and “salicylic acid” interchangeably).

A few ingredients are technically both alpha and beta hydroxy acids such as citric acid, which acts more like an AHA.

It’s not 100% clear how AHAs and BHAs work to exfoliate the skin – it’s likely to be a combination of the two actions described at the beginning: increasing cell turnover at the epidermis and unsticking stratum corneum cells. As well as just removing build-up of skin, they can also improve hyperpigmentation and reduce the appearance of wrinkles.

There are a few key differences between AHAs and BHA/salicylic acid:

  • Solubility: The commonly used AHAs (glycolic acid, lactic acid) are water soluble, while salicylic acid is oil soluble. Theoretically this means salicylic acid is better for treating oily skin and clogged pores because they can penetrate through sebum and sebum plugs, but there’s a lot of variation between people’s experiences. You’ll generally find AHAs in products for dry, ageing skin, and BHA in products for oily, acne-prone skin.
  • Sun sensitivity: Glycolic acid is documented to cause sun sensitivity for a while even after you finish using it, while salicylic acid isn’t. Salicylic acid has a UV protective effect while on the skin, due to the benzene ring in its structure which lets it act as a chemical sunscreen. You need to wear sunscreen while you use alpha hydroxy acids, and for at least a week after you finish – otherwise, you can actually cause more wrinkles and uneven pigmentation and sagginess than you started off with! And you should use sunscreen with salicylic acid anyway.
  • Other effects: Salicylic acid can have some anti-inflammatory action, depending on whether enough gets through the skin – it’s actually one of the active forms of aspirin. Glycolic and lactic acids are humectants that act to slow down the evaporation of water from the skin.

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How do enzyme exfoliants work?

pineapple-skin-care

pineapple-skin-care

You’ve heard of physical exfoliants and chemical exfoliants – now meet their less famous cousin, enzyme exfoliants! You’ll find them in a whole bunch of popular products, like Mario Badescu Enzyme Cleansing Gel, Jurlique Fruit Enzyme Exfoliator, MUAC Triple Enzyme Peel and DIY pumpkin, kiwi, papaya or pineapple masks.

What’s an exfoliant?

If you need a refresher, an exfoliant is a product which helps detach the outer layers of the skin. Physical exfoliants do this by buffing away at the surface like sandpaper, and chemical exfoliants do this by breaking apart the glue holding the cells together (read more about AHAs and BHA here). Enzyme exfoliants are a bit more like regular chemical exfoliants, but there are some key differences.

What’s in an enzyme exfoliant?

Enzymes are proteins which perform a specific job. The enzymes used for exfoliation in skincare are protease (or proteolytic) enzymes, which break down other proteins, including those keeping your older, outer layers of skin stuck on. In particular, they’ll usually be bromelain (from pineapple, often listed as Ananas Cosmosus (Pineapple) Fruit Extract), papain (from papaya, often listed as Carica Papaya Fruit Extract), pumpkin enzyme (listed as Cucurbita Pepo (Pumpkin)) or Bacillus bacteria.

(Interestingly, these enzymes’ proteolytic action is also why pineapple and papaya make great meat tenderisers! They break down some of the protein, which makes the meat less tough. Also, canned pineapple and papaya don’t work – the heating process denatures (screws up the shape of) the enzymes.)

What’s so great about enzymes?

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