Sue’s shampoo supposition…Do shampoos that don’t contain silicones also leave buildup in the hair over time? If so, what is it that builds up? I’m wondering specifically about LUSH solid shampoos. I’ve read reviews in which users complain of buildup — but of what?

The Right Brain’s reply:

In general, modern liquid shampoos don’t create a buildup problem. That’s a popular belief, but there’s very little scientific evidence to back it up. But could LUSH‘s solid shampoos cause buildup? Theoretically, yes. Let’s take a look at the key ingredients in their Godiva shampoo that make this product a solid.

LUSH ingredients

Sodium Lauryl Sulfate, Cocoa Butter, Cetearyl Alcohol, Glycerl Stearate & Peg – 100 Stearate, Cetearyl Alcohol, Stearic Acid

What does this mean? Some of these ingredients like SLS, you would find in a typical liquid shampoo. But the others are waxy type ingredients that are added only to allow the shampoo to be made into a solid bar. Being waxy type materials, they are not water soluble (if they were too water soluble, the bar would fall apart in the shower the first time you used it.)

Now, since these ingredients are not water soluble, they may not rinse completely from the hair, thus causing the buildup that you mentioned. Regular liquid shampoos would not have this problem since they don’t use these kinds of ingredients. Is that bad? Wouldn’t this waxy stuff also condition your hair? Maybe, but there are much more effective conditioning materials for shampoo systems.

The Beauty Brains bottom line

Lush Shampoo Bars are very cool products – they smell great and they’re fun to use. But if you notice build up when you use them, it’s probably because of the ingredients used to make the bars solid.