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Gone are the days of harsh cleansers that dried out your skin – everyone’s getting into gentle cleansers! What’s the science behind gentle cleansing, and how do you pick a gentle cleanser? Here’s the scientific background behind this skin-loving trend!
Want more about the science behind choosing and using the right cleansers, moisturiser and sunscreen for your skin? Check out The Lab Muffin Guide to Basic Skincare!
How Cleansing Damages Your Skin
Cleansing is the most damaging thing you do to your skin on a daily basis, but unfortunately it’s necessary to get rid of all the dirt, makeup, oil and sunscreen you’ve accumulated on your skin over the course of the day. These unwanted substances won’t come off with water though! That’s why cleansers usually contain surfactants, magical chemicals which can help the grime dissolve in water and wash away.
Surfactants are the key ingredients in pretty much every single cleanser: foaming cleansers, soaps, body washes, cleansing balms, cleansing oils and micellar water. In fact, the only common surfactant-free cleansing methods I can think of are oil cleansing and using a cloth with just water. (I wrote about how surfactants are in everything in this post on The Toast a couple of years ago).
As amazing and useful as surfactants are at lifting grime, they’re not always good for your skin. The outer layer of your skin (the stratum corneum or SC) consists of dead, protein-rich skin cells filled with water-binding chemicals (your natural moisturising factor or NMF), surrounded by carefully arranged oily lipids (mostly ceramides, cholesterol and fatty acids). It looks a lot like a brick wall, with skin cell bricks and lipid mortar. Together, these form a barrier against water evaporating from the skin into the environment, and against external irritants entering your skin.
When the SC’s structure is disturbed, skin becomes dry, itchy, flaky, red and irritated. Luckily, the SC is pretty hardy and holds up well against most things… but unfortunately, surfactants are VERY good at messing things up! Here’s what a harsh cleanser does:
Removes important stratum corneum components
Surfactants are amazing at removing grime, but they can’t tell the difference between the chemicals that make up your skin and the chemicals that aren’t meant to be there. Surfactants are good at removing lipids (particularly cholesterol) from your SC, which messes up its structure and makes it more susceptible to water loss. They also remove proteins and NMF components from your skin, meaning it won’t be able to hold onto water as effectively. This all leads to dry, dehydrated skin.
Remains in the skin, causing irritation and disruption
After cleansing, most of the surfactant gets rinsed off, but unfortunately not all of it. Some surfactant molecules will bind to proteins in the skin, causing them to denature (change shape) and swell. The more swelling, the greater the irritation. (Interestingly, this interaction with proteins is probably a bigger contributor to the “tight” feeling after cleansing than the loss of oils!) Additionally, surfactants can remain in the lipid “mortar” of the SC, changing its structure. Together, these effects lead to a compromised SC that’s prone to letting water escape and irritants enter.
Changes the pH of skin
Skin is acidic, meaning it has a low pH (around 5). This is important because a lot of the biochemical reactions that occur in skin only work within a narrow pH range. Surfactant-containing cleansers are particularly good at changing skin pH for long amounts of time, meaning that if your cleanser has a particularly high pH, then it’s going to hinder your skin from repairing itself. High pH also makes skin swell and reduces its flexibility.
If you’re acne-prone, there’s more bad news: high pH encourages the growth of acne-worsening Propionibacterium acnes bacteria (more on pH and bacteria in this post from Snow White and the Asian Pear).
Picking a Gentle Cleanser
A good cleanser will clean grime off your face while keeping your skin relatively intact. It’s difficult to tell just from the ingredients whether a cleanser will be gentle, but here are a few things to look out for:
The surfactants a cleanser contains makes the biggest difference in terms of how damaging it is.
Surfactants with small, negatively charged (anionic) head groups and tails 10-14 carbons long are particularly harsh. Larger head groups, uncharged (non-ionic) or neutrally charged (amphoteric/zwitterionic) heads and different tail lengths are milder.
Harsh surfactants with both these characteristics include:
- many soaps (e.g. “sodium XXate” – sodium laurate, sodium cocoate, sodium tallowate)
- sodium lauryl sulfate (aka SLS)
Milder surfactants that are much gentler on skin include:
- sodium laureth sulfate (SLES), especially in combination with cocoamidopropyl betaine (CAPB)
- sodium cocoyl isethionate
- alkyl sulfosuccinates (“XX succinate” in an ingredients list)
- alkyl sarcosinates
There’s also research showing that mixtures of surfactants make for gentle cleansers. Surfactants assemble into spherical micelles in solution. If a micelle is very small, it penetrates more easily into skin, causing irritation. Mixtures of surfactants tend to form large micelles and hence reduce irritation, so look for a bunch of the above names in the ingredients list. (You can read more about this phenomenon on KindofStephen.)
Interestingly, more foam doesn’t necessarily mean a harsher cleanser! Traditionally, foaming cleansers were made with irritating SLS, but there are a few methods of formulating cleansers to foam while still being gentle. For example, in some tests, low-foaming cleansers were more drying than foaming cleansers containing moisturising emollient ingredients.
As discussed above, high pH cleansers are more damaging, so look for cleansers with a low pH (less than 6). Unfortunately, most cleansers don’t tell you their pH, so you’ll have to do a bit of Googling or buy some pH test strips (universal indicator strips like these are very cheap, multi-square strips like these are a bit more precise though).
To preserve the pH of your skin, you’ll have to avoid soap. Soaps don’t work at pHs lower than about 9.5, which means they’ll never be truly mild, no matter how natural they seem.
Cleansers often incorporate moisturising ingredients like oils and humectants to replace what’s been stripped from the skin during cleansing. Look for oils like sunflower oil and mineral oil, fatty acids like stearic acid and humectants like glycerin and sorbitol in your cleansers.
Other tips for gentle cleansing
Use cooler water: I know it’s hard in winter, but hotter water increases the ability of surfactants to penetrate the skin and increases the stripping of lipids, proteins and NMF from your skin.
Use less cleanser: The less cleanser that touches your skin, the less damage you’ll get.
Don’t let it soak: The longer the cleanser stays in contact with your skin, the more time it’ll have to penetrate into your skin. Don’t let it stay on your skin for too long.
Cleanse less frequently: If you wash your skin with cleanser more than once a day, see if you can cut down. In the morning, if you’ve cleansed sufficiently the night before, you can just splash water on your face and pat it off.
Remove surfactant from your skin afterwards: Wipe-off products (e.g. micellar water, cleansing wipes) contain mild surfactants that can be left on the skin, but it’s still better to remove them. If you don’t want to do a full rinse, following your cleanser with a damp tissue will reduce irritation.
Follow up with moisturiser: Add water, emollients and humectants back into your skin with a moisturiser.
My gentle cleansing routine
Since I have oily skin, I tend not to worry too much about what cleansers I use in summer. In winter, however, my skin is very prone to dehydration (read about what dehydrated skin means here), so I have the annoying task of trying to find gentle cleansers that can effectively remove all my makeup and sunscreen without making me itchy. Here are the gentle cleansers I’ve been using to try to limit the damage:
QV Gentle Wash
QV is a brand that a lot of doctors recommend for sensitive skin, and QV Gentle Wash is one of their star products. The packaging and scent are boring, but it’s extremely gentle, with 15% glycerin to keep your skin hydrated, and a blend of mild surfactants that won’t dry out your skin. It also contains some polymers, which I’m guessing are there to help reduce skin penetration of surfactants. I found that it left my skin feeling clean but not tight, and the itch I usually get from winter showers has disappeared.
If you’re into bulk savings, a 1.25 kg bottle of QV Gentle Wash is only $18.99 at Chemist Warehouse. QV also has an Intensive Moisturising Cleanser which has a whopping 60% glycerin for even gentler cleansing.
- Lots of water-restoring glycerin
- Mix of gentle surfactants
- Fragrance free
- Handy hygienic packaging
- Budget-friendly ($18.99 for 1.25 kg)
- A bit boring
- No emollients to replace lost oil-based skin components
Ingredients: Aqua (water), Glycerin, Sodium Lauroyl Sarcosinate, Disodium Cocoamphodiacetate, Lauryl Betaine, Sodium Cocoyl Isethionate, Acrylates/ C10-30 Alkyl Acrylate Crosspolymer, Styrene/Acrylates Copolymer, Aminomethyl Propanol, Methylparaben, Propylparaben.
Dove Beauty Cream Bar
My other favourite body cleanser is Dove’s Beauty Cream Bar. It’s 1/4 cream, with lots of oily moisturising ingredients like stearic acid and lauric acid, which are good at sticking to skin and won’t rinse off. It does have a bunch of soaps in the ingredients list (sodium palmitate/stearate/palm kernelate), but since the pH of the bar is 7, they’ve probably been converted back into the fatty acids which will moisturise rather than strip skin. The other main surfactants (sodium lauroyl isethionate, sodium isethionate, cocamidopropyl betaine) are well known for being gentle. I found that my skin felt more moisturised than with QV Gentle Wash, but since I’m pretty clumsy, I kept dropping it and knocking it out of my soap dish.
- Lots of emollient moisturisers
- Gentle surfactants
- No parabens (only a problem if you’re allergic)
- Budget-friendly (4 bars for $7.99)
- Can feel a little heavy
- pH is a bit high
- Bar is less hygienic than liquid
Sodium Lauroyl Isethionate, Stearic Acid, Sodium Palmitate, Lauric Acid, Aqua, Sodium Isethionate, Sodium Stearate, Cocamidopropyl Betaine, Sodium Palm Kernelate, Glycerin, Parfum, Sodium Chloride, Zinc Oxide, Tetrasodium EDTA, Tetrasodium Etidronate, Alumina, Alpha-Isomethyl Ionone, Benzyl Alcohol, Butylphenyl Methylpropional, Citronellol, Coumarin, Hexyl Cinnamal, Limonene, Linalool, CI 77891.
Nivea Soothing Cleansing Mousse
Nivea Soothing Cleansing Mousse is currently my go-to face wash. It comes in a self-foaming pump which is perfect for my laziness, plus I find that it makes the product last longer than if I doled it out myself. It contains a lot of humectant sorbitol and glycerin, as well as emollient sweet almond oil to moisturise the skin, though it doesn’t feel like it leaves a residue. The surfactants are super gentle. I was quite surprised at how effective it was, even though it felt super mild – one pump was enough to get rid of all my everyday make-up.
- Lots of humectants and emollient moisturisers
- Gentle surfactants
- Handy self-foaming pump
- Doesn’t feel heavy
- Reasonably priced ($9.99 for 150 mL)
- May not be strong enough for heavy make-up
- Scented (but very mildly)
Aqua, Sorbitol, Glycerin, Decyl Glucoside, Disodium Cocoyl Glutamate, Glyceryl Glucoside, Prunus Amygdalus Dulcis Oil, Panthenol, Propylene Glycol, Polyquaternium-10, PEG-40 Hydrogenated Castor Oil, PEG-200 Hydrogenated Glyceryl Palmate, Sodium Sulfate, Sodium Chloride, Citric Acid, Sodium Benzoate, Butylphenyl Methylpropional, Benzyl Alcohol, Geraniol, Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde, Parfum.
Antipodes Hallelujah Lime & Patchouli Cleanser
I’ve been using the relatively fancy Antipodes Hallelujah Lime & Patchouli cleanser for heavy make-up removal. It’s a cream cleanser that’s very effective for dissolving make-up. It contains glycerin, plus a bunch of beneficial plant oils (avocado, macadamia, jojoba) high up in the ingredients list. I’ve been using it before the Nivea cleanser when my make-up is particularly heavy, but a few times I’ve been lazy and simply wiped it off, and it was fine. I’m sure there are cheaper products out there, but this is a nice indulgence.
- Very low surfactant content
- Smells good
- Handy pump bottle
- Effective at removing make-up
- Lots of glycerin and oils for moisturising skin
- Scents may be irritating to sensitive skin
- Feels a little heavy on skin if you don’t wash it off
- Relatively expensive ($38.99 for 200 mL – not sure why it’s so expensive on Amazon)
Aqua (Water), Glycerin, Persea Gratissima (Avocado Oil), Macadamia Ternofolia (Macadamia Oil), Buxus Chinensis (Jojoba Oil), Wheat Straw Glycosides, Cetearyl Alcohol, Daucus Carota Sativa (Carrot Oil), Macropiper Excelsum (Kawakawa Leaf), Citrus Nobilis (Mandarin Oil), Citrus Limetta (Lime Oil), Pogostemon Cablin (Patchouli Oil), Tocopherol (Vitamin E), Gluconolactone, Sodium Benzoate, Calcium Gluconate, Citrus Grandis (Grapefruit Seed Extract), D-Limonene, Linalool, Citral.
If you enjoyed this article, you might be interested in The Lab Muffin Guide to Basic Skincare. It’s an all-in-one guide with everything you need to build the foundations of a science-based skincare routine.
These products were provided for review, which did not affect my opinion. This post also contains affiliate links – if you decide to click through and support Lab Muffin financially (at no extra cost to you), thank you! For more information, see Disclosure Policy.
HA Epstein, Anatomy of a skin cleanser (open access), Skinmed 2005, 4, 183-185. (reposted on Medscape)
RM Walters, G Mao, ET Gunn & S Hornby, Cleansing formulations that respect skin barrier integrity (open access), Dermatology Research and Practice 2012, doi:10.1155/2012/495917 (authors affiliated with Johnson & Johnson, Neutrogena)
BL Kuehl, KS Fyfe & NH Shear, Cutaneous cleansers (open access), Skin Therapy Lett 2003, 8, 1-4.
KP Ananthapadmanabhan, DJ Moore, K Subramanyan, M Misra & F Meyer, Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing, Dermatol Ther 2004, 17 Suppl 1, 16-25. (authors affiliated with Unilever who make Dermalogica, Dove, Lux etc.)
HC Korting & O Braun-Falco, The effect of detergents on skin pH and its consequences (pdf link), Clin Dermatol 1996, 14, 23-27.