Thread by @LabMuffin

🗣️ SULFATES 🗣️ AREN'T 🗣️ EVIL 🗣️ A Thread!

Historically, sodium lauryl sulfate could be quite harsh, but in modern cleansers it's been made much gentler.

The most common way: combining different surfactants into the one product. This is pretty much every cleanser these days!

This encourages SLS molecules to get into clusters (micelles) that are too big to penetrate the skin - it's when individual SLSes go off on their own and dig into skin that you get irritation.

Tech version: mixed micelles lower the critical micelle concentrations (CMC).

🧪Special polymers can also be used to stop SLS molecules from wandering off alone

🧪 Anti-irritant ingredients (polymers, emollients, glycerin, antioxidants, hydrolysed proteins) can also be added to cleansers to decrease irritation

So just seeing SLS on a cleanser's ingredient list doesn't mean it'll be irritating!

But what about other sulfates - especially SLES (sodium laureth sulfate)?

SLES is quite a lot less irritating than SLS, even without irritation-reducing strategies. I think it just got this reputation because its name is pretty similar (I have memories of being called "Michael" a lot because there were three Michaels before me on the class roll 😑).

There's an older experiment that tested the irritancy of a bunch of surfactants - SLES turned out to be the mildest, beating:

SLS
TEA-lauryl sulfate
ammonium lauryl sulfate
disodium cocoamphodiacetate
sodium lauroamphoacetate
sodium methyl cocoyl taurate

doi.org/10.3109/014805…

And remember, even SLS (the most irritating in this study) can be made gentle by the formulation!

🗣️ LEAVE 🗣️ SLES 🗣️ ALONE 🗣️

More on cleansing myths in my latest blog post/video: labmuffin.com/are-you-washin…

A previous thread on foaming vs non-foaming cleansers:

https://twitter.com/LabMuffin/status/1417659320464904195?s=20