Stearyl Citrate for Pearl in Shampoo

What is Stearyl Citrate used for?

Stearyl citrate is a newer type of product that is used to create a opalescent effect.  It is used in shampoos, body wash, or other type of foaming surfactant system.  We chemists like to use these products because they give a really nice effect and make the product look good both in the bottle and in your hand when it is dispensed.  We call products like these “pearlizers” because they make products look like a pearl.  There are other products that do this as well, and the most common are glycol stearate and glycol distearate.  You’ll see these often on any product with a pearly appearance.  We could have used any of these, but the stearyl citrate seemed to have the best look and was easiest to formulate in the product because it came in a blend.

How does Stearyl Citrate work?

Basically, the way it creates the pearl effect is through light refraction which we discussed in our amodimethicone post and provided a link in that article if you want to study it further.  The way it does this is by aligning itself so the molecules slightly bend light as it passes through.  The molecules sort of “stack” facing opposite ways.  I was trying to find a good article on the phenomenon but couldn’t find anything online.  I have these books called the Surfactant Series from CRC press. They go into great detail on all these mechanisms. You can buy the one on pearl agents here.  You can also get all kinds of other information on how different surfactants work.

Is Stearyl Citrate safe?

The CIR reviewed stearyl citrate and found it safe as used, which is the best possible rating.  You can find the report here, and it also goes into a few other ingredients that are citric acid based (including citric acid).