I want to discuss making a more complex lotion, one with humectants and skin loving goodies in it, but before I can do that, I really feel like you need to understand how lotion works with your skin and also why we use certain ingredients. So yes, this is going to be another long blog post!
The Chemistry of Your Skin (this next part was taken in large from the Point if Interest blog. Kudos to Susan for having done such thorough research).
Healthy skin contains about 10% water. The water in your skin influences elasticity, tensile strength, barrier characteristics, and the appearance of your skin. If you’re running with less than 10% in your skin, you’re too dry and you’ll need to get more moisture in there somehow. You can live in a more humid climate (apparently 60% is ideal, so those of us in Kansas are lucky because the average here is 66%, although the barometer in my house tells me it’s only 50% now that it’s winter), drink more water, prevent further damage, or draw or apply water to your skin.
Our stratum corneum-the outermost layer of your skin-contains a natural moisturizing factor (NMF) of its own. It is a complex mixture of water soluble compounds, such as amino acids, organic acids, urea, and inorganic ions. This NMF makes up about 10% of the stratum corneum. Some major components of the NMF are sodium lactate, urea, and sodium PCA. When we absorb water from the atmosphere (or lotions!), this water dissolves these molecules and they act as humectants in our skin, drawing water in from the atmosphere. But if we live in arid climates, have done some kind of damage to our skin (side note: a week in the desert every year is damaging to your skin!), the NMF gets compromised and doesn’t keep us moisturized. This is where we use our lotions with humectants to help protect and repair the damage.
But water alone isn’t going to quite cut it. It evaporates too quickly to really make a huge difference. This is where our oils and other ingredients come in.
We need three things to moisturize our stratum corneum:
1) Occlusion: We need to reduce water loss (trans epidermal water loss or TEWL), from our skin. So we use oils, film formers, and other ingredients to trap the water in our skin.
2) Humectancy: Humectants will help retain water in the skin and will draw water from the atmosphere.
3) Emolliency: We add moisturizing ingredients so we aren’t bothered by the rough, dry, skin, and to keep it from getting further damaged.
So how do we make products-in this case a lotion, and later a cream-with all this in mind?
There are many emollients you can choose from- oils and butters are the most common. Also known as vegetable triglycerides, they are the main ingredients we use in lotions to soothe and moisturize our skin. Different oils offer different benefits-longer shelf life, lovely vitamins-so you can choose you oils and butters to suit your needs.
Hydrolyzed proteins like oat, wheat, corn, silk, soy, and baobob are film formers and emollients. They contain oligosaccharides and amino acids. They are water soluble, so not appropriate for oil only creations like body butters, but exactly what we can use in a lotion.
They work on your skin by penetrating the outer layers of the stratum corneum and function as moisturizers. They also work as irritant mitigators, which makes them a great addition for facial products. In hair care products, they can penetrate the cuticle into the cortex of the hair, and help reduce cortex damage.
They also help you retain moisture in your skin and hair, so they have some humectant properties.
This is the way we prevent TEWL (trans epidermal water loss) from our skin. We want to trap that water and prevent it from evaporating from our skin, and protect our skin from further damage while it repairs itself.
All the things discussed so far that offer emolliency- oils, butters, proteins-will trap in moisture and do double duty of making the skin feel softer. But there are other ingredients that we can use to occlude the skin called barrier ingredients.
The butters-cocoa, shea, mango-are great barrier ingredients. Each butter has its own benefits, but the key is that they stay on your skin. (Personally I’m very fond of shea butter, I prefer it almost always over anything else).
You can add aloe vera as gel, juice, or powder in about any quantity you want in your recipe. Aloe vera has trace electrolytes that may be beneficial to your skin.
There are other things that are great for occlusion, like beeswax and allantion, but for the purposes of our lotion we don’t need to cover them right now. Just think of everything that might be a physical Barrier on your skin in lotions and creams, body butter and lotion bars.
Humectants: What are humectants? They are hygroscopic ingredients that can draw moisture from the atmosphere to your skin. Ideally, we use them at 2-5% in lotions to make skin feel more moisturized. Currently there is some debate if using humectants in a non-humid climate such as the desert states is effective. It’s interesting for sure!
My favorite humectants are:
Glycerin-cheap, easy to use, and plentiful. It helps thicken your lotions a little. If you use it in surfactant based systems like shampoo, it’s fantastic as it’s actually will increase bubbles. Use at up to 5% is what she has written here, although Susan goes ont to recommend 2-3% as feeling “less sticky” and I’ve always used at around 10% with no problems. To each their own, I guess.
Silk peptides: Silk molecules are the same size as the protein molecules in your skin and hair, which allows silk to replace areas of damage and strengthen those areas. It makes your skin and hair silky soft and smooth with very little use. Use at about 2-3%
Propylene glycol: readily available, but I’ve never tried it. A lot of people don’t like it because it has a negative image as being a harmful chemical, although it’s actually very safe.
Sodium Lactate: derived from beets, this product is used to harden soap bars so I always have it around. At 3%, it has exfoliating properties as well as humectant properties. Win win! It also has some anti-acne properties, if that’s a concern for you. Works great in water based products like toners. It’s been my new favorite ingredient and I find I’m putting it in everything.
So what will we use this time? Just silk and glycerin.
Modified “First” Lotion with Humectants
15% oils (liquid oil, like olive, sweet almond, sunflower)
5% shea butter
6% Ecomulse or other complete emulsifer
2% silk peptides
Cool down phase
1% fragrance or essential oil
0.5%-1% preservative, as indicated on bottle
Weigh out your water phase ingredients, making sure to tare the scale inbetween each one, in a heat proof container such as a pyrex measuring cup and cover loosely with foil. Measure out your oil phase ingredients, making sure to tare the scale in between each addition, and place both cups into a saute pan that contains about 1″ of water. Bring water phase ingredients to boil then simmer for 20 minutes. Oil phase ingredients should melt during this time and need to be stirred occasionally. When 20 minutes is up, combine both cups in a heat proof container and whisk. Voila! Lotion! Mix with stick blender for a few seconds until light and fluffy, then whisk a little more. Let cool until contents are just warm to touch. Add cool down phase ingredients and whisk again until well incorporated. Decant to pump bottle.
The best way I know to get lotion in a pump bottle is to use a funnel and a flexible silicone spatula for smashing it around in the funnel so it goes down. Susan at Point of Interest recommends putting your lotion in a piping bag, like icing goes in, and squirting it in the bottle that way. I haven’t tried it, yet, but if my lotion ever thickens up on me a lot before I can get it in the bottle I will keep that in mind for sure.
I’m sure you’re curious how to make a thicker lotion, like a cream, to use on elbows and feet. Here’s a recipe:
10% oils (Olive oil is a great choice here, as it’s thick and rich with vitamins A, E, and D)
10% shea butter-you can use any butter like shea, mango, sal, or even cocoa butter.
8% coconut oil (Extra virgin kind, that’s solid at room temperature. NOT the fractionated coconut oil!)
7% Ecomulse or other complete emulsifier
3% silk peptides
Cool down phase
1% essential or fragrance oil
The directions are the same as for a lotion, except you mix it with the stick blender a little more and decant it into a jar instead of a bottle. A small, 4 oz Bell jar would work, or even a small jelly jar although there would be extra room at the top. If you want to get fancy and make this an awesome foot cream, add 5% (approx 5 grams for a 100g product) menthol crystals to the oils phase (keep your face out of the steam to avoid irritation) and you’ll have a nice tingly foot cream when it’s all done. Menthol crystals are easily available on Amazon or from Brambleberry and Bulk Apothecary. Lotioncrafters has started carrying them, too. You can also just increase the amount of essential oil up to 5% and use peppermint and camphor (if you have camphor).
That’s all I have for lotions… Be sure to ask questions if you have any!