Clean Without the Squeak: How to Build a Truly Gentle Cleanser
For decades we were taught that clean skin should feel "squeaky". Today we know that squeak is the sound of skin being stripped of the lipids that keep it comfortable. A great cleanser removes dirt, sunscreen and excess oil, and leaves your barrier alone. Here's how to build one.
How surfactants work (in 30 seconds)
Surfactants are molecules with a water-loving head and an oil-loving tail. They surround oily grime and let water rinse it away. The catch: they can't always tell the difference between "dirt" and "your skin's own lipids and proteins", and some are much more aggressive than others.
The harsh benchmark: SLS
Sodium Lauryl Sulfate (SLS) cleans and foams brilliantly. It's so reliably irritating that dermatology researchers use it as a standard model for testing how skin reacts to irritants (Oosterhaven et al., British Journal of Dermatology, 2019). It still has uses (some rinse-off hair and body products, and it's milder in clever blends), but it's not the hero of a gentle face wash.
What makes a cleanser mild
1. Choose milder surfactants. In an independent study of eight surfactants on 105 patients, Sodium Cocoyl Glutamate, Sodium Lauroyl Oat Amino Acids and Disodium Cocoamphodiacetate were the best tolerated (Corazza et al., Dermatitis, 2010). Other gentle favourites:
- Amino-acid surfactants: Sodium Cocoyl Glycinate, Sodium Cocoyl Alaninate
- Glucosides: Coco Glucoside, Decyl Glucoside
- Isethionates and taurates: Sodium Cocoyl Isethionate, Sodium Methyl Cocoyl Taurate
- Amphoterics: Cocamidopropyl Betaine, Sodium Cocoamphoacetate
2. Blend them. Surfactants are gentler in teams. A review of mild cleansers notes that synthetic detergents ("syndets") are less irritating than alkaline soaps, and that synergistic combinations of surfactants improve mildness (Ananthapadmanabhan et al., Journal of Drugs in Dermatology, 2019; one author works for a major personal-care company). Another review explains that adding amphoteric co-surfactants or polymers makes surfactant systems less aggressive, partly by forming larger micelles that penetrate skin less (an industry-authored review: Walters et al., 2012).
3. Mind the pH. Healthy skin sits around pH 4.7, and soaps and even tap water push it upward (Lambers et al., International Journal of Cosmetic Science, 2006). Aim for a face cleanser around pH 5–6 (our pH guide shows how).
4. Put something back. Glycerin, panthenol or a light oil help skin feel comfortable after rinsing.
A gentle gel cleanser blueprint
- Primary mild anionic: sodium cocoyl glutamate or sodium cocoyl glycinate
- Amphoteric partner: cocamidopropyl betaine or sodium cocoamphoacetate
- Non-ionic helper: coco glucoside (adds mildness, a creamy feel and helps stabilise foam)
- Keep the total active surfactant modest. Check each supplier's "% active" and use range (for example the sodium cocoyl glutamate entry), and remember face washes need less cleaning power than body washes.
- Care: Glycerin and Panthenol
- Thickener: Xanthan Gum or Sclerotium Gum
- pH adjusted to about 5–5.5 with Citric Acid, plus a preservative that works at that pH
Even gentler formats: a cleansing milk (a light emulsion with very little surfactant), a cleansing balm for the first step of a double cleanse, or a powder-to-foam cleanser like the ones in our waterless beauty post.
The "is it too strong?" test
After rinsing and patting dry, wait five minutes without applying anything. Skin should feel comfortable, not tight, itchy or shiny-taut. If it feels tight, lower the surfactant level, swap in a milder primary surfactant, or add more glycerin.
Shop Surfactants & Cleansing Agents, Cleansing Agents and Cleanser & Face Wash Ingredients.