SLS and SLES in soap: what are they and why does The Highland Soap Company leave them out?

Walk along the shelves of soap and personal care products these days and you will increasingly come across the claim “SLS-free” or “SLES-free” — including on the packaging of The Highland Soap Company. But what exactly are these substances, and why does this Scottish family business deliberately choose not to use them?

What are SLS and SLES?

SLS (sodium lauryl sulfate) and SLES (sodium laureth sulfate) are so-called surface-active agents, or ‘surfactants’. In plain language: they are the substances that make soap, shampoo and shower gel lather nicely and loosen grease and dirt from skin or hair. They are cheap to produce and very effective, which is why they have been found in much of the soap, shampoo and toothpaste on the shelves for decades.

Why do some brands choose to avoid them?

Important to know: at the concentrations used in cosmetics, SLS and SLES are generally considered safe. So this is not about a ‘dangerous’ substance. What the discussion does revolve around is skin sensitivity: precisely because SLS and SLES are so effective at loosening grease and dirt, they can affect the skin's natural protective barrier. With average skin you usually notice little of this, but people with dry or sensitive skin sometimes experience it as extra drying or mildly irritating.

What does The Highland Soap Company use instead?

The Highland Soap Company makes its soap using the traditional cold-process method: a slow, artisanal process in which natural oils and fats react with lye. This method naturally produces glycerine, which — unlike in much industrially produced soap — simply stays in the soap instead of being removed. That glycerine helps keep the skin moisturised rather than drying it out. Combined with natural, partly organic and sometimes locally or wild-harvested Scottish ingredients (such as Hebridean seaweed and bog myrtle), the result is a soap that cleanses without the vigorous foaming action of SLS or SLES.

Who does this make a difference for?

This choice is particularly relevant for people with dry or sensitive skin, for those consciously looking for natural, artisanal care, and for anyone looking for a gift with an authentic story behind it — instead of yet another standard bottle of shower gel.

Curious about the difference?

Discover the handmade soaps, hand creams and care sets from The Highland Soap Company at Mood Company — made in the Scottish Highlands, without SLS or SLES, and full of natural ingredients.