Why You Won't Find SLS in The Best UK Shampoo Bars!

4 min read 2 Comments

Child with foamy shampoo hair

What is SLS and why should we avoid it?

The most common sulphate shampoo ingredient - Sodium lauryl sulphate (SLS) - has been used in many commercial formulations for years because it is inexpensive, offers good lathering and can even be thickened easily with salt, which is also cheap and in abundance! 

It is an ‘anionic’ surfactant, so it cleans dirt and grease from our hair and is very foaming; this last point is an important consideration as consumers generally associate foaming with cleaning (whether it be for your hair your hands or even your car!), due to its small molecule (micelle) size.

Foamy car wash

However, in the past few years, there has been an increase in demand for SLS-free shampoo and conditioner products.  This is because shampoos with sulphates have developed a reputation in the beauty industry for causing frizzy, dry hair and the fading of applied hair colour. 

Salons offering keratin treatments (a lengthy smoothing treatment that seals the hair cuticle with a coating of protein that eliminates frizz, and adds softness and shine), for example, will now frequently recommend that their clients only use sulphate-free shampoo and conditioners.

Girl with coloured hair

Secondly, SLS has an alkaline pH8-9 which isn’t good for our hair (see more on that here) and isn’t tolerated very well by our skin.  It is considered a harsh surfactant versus almost every other surfactant on the market and the industrial strength version is even used to strip grease from car engines!

As the SLS molecule is small, it can penetrate the skin deeply, irritate it and leave it more exposed to the absorption of other irritants as well.  It also doesn’t rinse off our skin very easily, particularly in hard water areas, which again can lead to skin tightness and further irritation such as dryness, rashes and itching.

Woman itching her scalp

Nowadays, there are far better alternatives on the market that we are able to use in our zero waste shampoo bars that won’t strip the hair or irritate the skin.  We all have to learn to treat our hair like we would a lovely piece of fabric or a cashmere jumper; surely it’s more valuable to us than either of these? 

We wouldn’t use harsh detergents on our most valuable possessions without expecting to see negative results and, ideally, we also wouldn’t apply too much heat to them or stretch them too much when they were wet either - so why on earth would we do that to our hair?

It stands to reason that we should use the best, most gentle ingredients available to keep our hair looking soft, smooth and in top condition for years to come.

Woman with flowing hair

When we create our best shampoo bars in the UK, we still want anionic surfactants, negatively charged, foaming, and bubbly surface cleaning agents that will trap oil and dirt and wash it away leaving our hair lovely and clean.

Most importantly, a lot of people confuse the names of product ingredients and there is a great deal of 'misinformation' flying around as a result of this. Here we are clearly talking about sodium lauryl sulfate otherwise known as SLS. Whereas in our shampoos we use sarkosyl, which is a natural gentle cleansing and foaming agent, is non-irritating and does not strip the hair and it is fully biodegradable and non-toxic to marine life. Not only that but we also use a custom-made palm oil free version to ensure that we are even kinder to the planet.

However, in order to achieve this result we need to choose gentle, more acidic primary surfactants with a larger micelle size with good rinsing qualities. This, combined with other anionic, non-ionic, amphoteric and cationic surfactants will also increase the anionic micelle size and also  increase the overall mildness, all bringing different characteristics to create the best balanced shampoo bar blend.

As a big plus to the above it creates a more eco-friendly shampoo bar as no water is required to make it and less water is required for wash off. 

Water droplets

In order to achieve this wonderfully effective luxury product we include seven different surfactants in our solid shampoo bars.

By then adding protein, cationic polymers and plant-based emollients, these will further increase mildness to the overall blend, add viscosity, increase foam stability and density and overall softness. 

Finally, adding in Pro-Vitamin B5, a humectant that draws water from the atmosphere to your hair and skin, strengthens hair strands and smooths hair by making the cuticle close tighter and increases shine. We then have the perfectly balanced best shampoo bar in the UK that is going to give you the result you all want - fantastic hair!

A shampoo bar and a conditioner bar

Afterall that, don’t forget for the best results to follow your shampoo treatment with our detangling cationic zero waste conditioner bars!

Best wishes,

Rebecca and The Solid Bar Company Team

PS. And while you are here why not check out this essential read on "5 Ways Fake 'Shampoo' Bars Damage Hair!"

2 Responses


May 19, 2020

Thanks so much for your comments and so glad to hear of how the hair care bars are working for you. It’s so nice to hear that and also from others having similar experiences as well as experiencing it myself. It certainly makes all the hard work put in to formulating them worthwhile.

Jules Winter
Jules Winter

May 16, 2020

I wanted a solid shampoo bar and these weren’t my first choice. However, at the point where i was going to give up because my hair felt so awful… i tried these, the woodland shampoo and the woodland conditioning bar. Strangely from the first use my hair felt soft, silky and manageable and with each wash since it has been the same and better. They are now my only choice of shampoo and conditioner.
I have bleached hair that if I didn’t actively condition went like straw; it was frizzy, sort of sticky with a heaviness that never felt right. Now I use a bristle brush and hairdryer and can achieve silky smooth hair with or without its natural wave every single time and the added bonus is that I don’t need to straighten my hair. Before the cuticles of my hair were never flat unless I used straighteners. Just give it a go you really don’t have anything to lose.

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