The Surfactant
System

What SLES actually does to the scalp

Sodium Laureth Sulfate is found near the top of the INCI list in the majority of commercial shampoos — including many priced above €40. It is effective, cheap, and produces dramatic foam. It is also indiscriminate in what it removes.

SLES strips sebum effectively — but sebum is not simply unwanted oil. It is the medium through which the scalp maintains its acid mantle: the protective film that keeps the scalp’s pH between 4.5 and 5.5. Strip it too aggressively and you disrupt both the barrier and the microbiome that lives within it.

For many people, the result is a cycle: over-cleansing leads to dryness, which triggers increased sebum production as compensation, which leads to more frequent washing — and more SLES. The product creates the condition it claims to treat.

SCI + CAPB: effective and selective

Sodium Cocoyl Isethionate (SCI) and Cocamidopropyl Betaine (CAPB) are both derived from coconut oil. SCI is an anionic surfactant that lifts dirt and sebum with a significantly milder interaction with the skin protein structure than SLES. It is used extensively in baby and sensitive-skin formulations for this reason.

CAPB is an amphoteric surfactant that reduces the irritation potential of the primary surfactant, improves foam stability, and helps maintain the mildness of the overall system. Together, SCI + CAPB achieves effective cleansing while respecting the scalp’s acid mantle and microbiome environment.

Why this matters for Bồ Kết

Bồ Kết saponins function as a secondary surfactant alongside the SCI + CAPB base. They contribute natural cleansing activity and authentic botanical character — but they do not produce the stable, controllable foam that a modern formula requires on their own. The combination delivers mild, effective, microbiome-respectful cleansing with the full botanical character of the Vietnamese tradition.