More information on calculations, Chris B from the Dish asks: I was just wondering what oils/butters you recommend adding to a lotion to make the lotion last longer on the skin? I have tried many of your formulas (love a few of them) but after about two hours, the moisturizing effect is gone and my legs are flaky again. Are there any oils in particular I should be using?
I think there are loads of different opinions on this - and I would encourage you, my lovely readers, to share your thoughts in the comments - but I don't think it's about the type of oils. I think it's about the combination of occlusive ingredients and humectants rather than the oils.
There's a difference between moisturization and hydration. Moisturizing is about creating an occlusive barrier to keep the water we have in our skin in our skin and preventing transepidermal water loss. Hydrating is about binding water to something like a humectant and keeping it on our skin. (Check out this post for way more details!) When we combine the two, we can make something seriously awesome for dry skin!
For dry skin, we want to bring water to the skin, which is why something like an anhydrous or without-water whipped butter, lotion bar, or oils only balm will do nothing for your skin type. We want to use oil-in-water lotions to bring moisturization and hydration to your skin!
If I want to make something for dry skin, I think about adding a humectant like glycerin, sodium lactate, and so on, and an occlusive ingredient to trap in that moisture. So I'd want to make something with cocoa butter, allantoin, or dimethicone - the three approved occlusive ingredients - and a lovely humectant.
Also consider the viscosity of the product you're making. If you make a light lotion, it'll offer less moisturizing than a body butter because the product isn't as thick!
honeyquat, and 2% propylene glycol, for example, - that had some great occlusive ingredients - let's say 10% cocoa butter, 2% dimethicone (cool down), and 0.5% allantoin - combined with some oils that offer great barrier repair properties - anything with linoleic acid, like soy bean oil, rice bran oil, or pumpkin seed oil, to name a few. (You could also try anything with gamma linoleic acid, like evening primrose or borage oil.) I'd add ingredients like panthenol - humectant and wound healer - and perhaps a hydrolyzed protein to offer some film forming.
This body butter with a few substitutions would be very nice, but then again, any of the recipes on this blog using those ingredients would be very nice! (As an aside, the body butter the way I made it stays greasy on my legs well into the next day if I apply it night! It's not too greasy, just enough that I know it's there!)
What is dry skin?
Impaired skin barrier repair mechanisms
Lower hydration levels
What ingredients could we use for dry skin? (Part one)
What ingredients could we use for dry skin? (Part two)