Friday, March 30, 2012

Formulating for dry skin: Lower hydration levels

In an ideal world, we'd all live in climates with 40% to 60% humidity and a lot of cases of dry skin would go away. (And in that same ideal world, chocolate would be calorie free and people would treat intellectual pursuits the way they do sports, but I digress...) But we don't, so we need to turn humectants and other moisturizers to help our dry skin feel more hydrated.

Our natural moisturizing factor contains amino acids (40%), sodium PCA (12%), lactate (12%), urea (7%), ions (18.5%), sugars (like glycerol - 8.5%), and a few other things. We want to draw water to our skin from the atmosphere, so we want to use humectants like sodium lactate, sodium PCA, glycerin, panthenol, honeyquat, and so on in our products.

If you're heard the claim that using glycerin in a dry climate can draw water from your skin, click here to see the research I've done on the topic. My conclusion: Use glycerin with an occlusive ingredient for awesome moisturizing action.  

Also think about the stratum corneum lipids found between our skin cells. This is where the lovely linoleic acid containing oils can help our skin's dryness levels.

The water soluble natural moisturizing factor is found inside the corneocytes; the lipid soluble stratum corneum lipids are found outside the corneocytes. (I really recommend reading the series on skin chemistry from start to finish if this interests you!) 

What can we do to increase hydration levels in our skin?

1. Live in a more humid climate, or create one with a humidifier. (I'm currently using a lovely one by Sunbeam, a cool mist humidifier that can run for something like 30 hours before it needs refilling. I bought it for about $25 from London Drugs, so it's an affordable one!)

2. Add humectants into your products and add an occlusive ingredient to make sure you trap that water against your skin. And definitely re-apply those products regularly throughout the day.

3. Use only really mild cleansers for our skin and moisturize after cleansing. Ensure our products are pH balanced for skin (for instance, no using really alkaline surfactants like decyl glucoside without modifying the pH) and increase the mildness of those products.

Join me for a little more information about humectants tomorrow before we get into a series of formulating and modifying products for dry skin.

Related posts:
Question: What's the difference between moisturizing and hydrating?
Skin chemistry & types section of the blog
Better crafting through chemistry: Humectants


Ruth said...

I can't hardly wait.
I am needing face moisturizer, (now)
my store bought is about gone.
I sooo want to make my own.
All those lovely sounding ingredients from,
LotionCrafters, and The Herabire, have really been calling me...but I just don't know how to formulate & put them together, in the proper way, to make sure they work
I Love your blog..
It is the first thing I check on,
in the mornings..
When a new post is not there, I am disappointed, but I totally understand, you have a life too..
And you are so gracious to share, when you can.

twobloomsdesignstudio said...

Great information, I look forward to your future posts. If you are wanting to keep your product vegan what can you use to replace Honeyquat?


Susan Barclay-Nichols said...

Look at the other humectants to see what works for you...(and there will be more posts in the next few days). I'm not vegan and I don't know any vegans, so it's not something I've had to consider.

Better crafting through chemistry: Humectants
Questions about humectants

Brandi Yates said...

Ive been adding essential oils to my humidifier. Would it be safe to add dpg and polysorbate to mix and disperse the oils or not necessary?