Friday, January 3, 2014

What do you want to know? What's up with myristic acid?

In the What do you want to know? post, Leann asks: I was given some Myristic Acid. I know this is a fatty acid used in medical products and food. It can increase absorption is what I've found in searches but is there any way you could elaborate on its practical uses in formulating bath & body products?

Myristic acid (aka tetradecoanoic acid) is a fatty acid, much like stearic acid. Stearic acid is a saturated fatty acid composed of 18 carbon atoms, and myristic acid is a saturated fatty acid composed of 14 carbon atoms. You can find it in palm kernel (15.7%), coconut oil (18.3%), babassu oil (14-20%), and murumuru butter (not sure). Myristic acid has a melting point of 54.4˚C (stearic acid melts around 69.6˚C). And it's considered a penetration enhancer.

Related posts:
Fatty acids
Hydrogenation (more about saturation here)

Everything I've read suggests using it as you would stearic acid, as a thickener in a lotion or in a situation where you want a little more thickening or stiffness. It is oil soluble, so you can't use it in something like a body wash or a toner.

You might recognize the myrist- prefix from things like isopropyl myristate or myristamine oxide. That means those ingredients are derived from myristic acid. 

I wasn't able to find the HLB value for this ingredient. Sorry. It seems like there's a lot of information on using it for making soap - apparently it has excellent lathering properties and cleansing power, which is why I guess we see a lot of palm kernel oil and coconut oil in soap making - but not a lot about using it in our cosmetic products. Here's a report stating that myristic acid is safe in the amounts used in cosmetics. And here's more information than you ever wanted to know about the chemistry of myristic acid!

Let us know when you use it! We're dying to know about the skin feel and viscosity building characteristics of this fatty acid!


Chrys Rocha said...

26% on Muru Muru butter.

Chrys Rocha said...

And also 26% on tucum√£ butter!

Uri Zadok said...

Strictly speaking (as far as I know), compounds that are ionic (such as sodium lauryl sulfate, or sodium laureth sulfate), or that can be ionized (such as stearic acid, or in this case, myristic acid) do not have HLB values. The HLB system was developed for nonionic surfactants.

Sarah Johnson said...

Ucuuba butter. I found a source that says it's 75% myristic acid.