Monday, March 16, 2015

Weekday Wonderings: How to make a longer lasting lotion?

In this post, 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!

So what would I suggest? I'd make something filled with humectants - say 3% glycerin and 2% sodium lactate or 3% glycerin, 2% 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!)

Related posts:
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)

7 comments:

beckster said...

Here, here! I agree completely with your assertion that it is about hydration more than moisturization. I have very dry skin, and I find that lotions and butters only work well if I use them straight out of the bath or shower when my skin is already plumped up with water. Otherwise, there is nothing for the occlusive layer to hold in.

Susanna Originals said...

Susan, can you use glycerine in an anhydrous recipe? For instance, if you were making a body bar could you replace 2 or 3% of the oil with glycerine?

ChrisB from the Dish said...

Hi Susan, I don't have dimethicone or allantoin, but will make a thick butter with glycerin, sodium lactate, cocoa butter, soy bean oil, evening primrose oil, and hydrolyzed oat protein. Keep your fingers crossed!

Thanks!

melian1 said...

i also use several humectants like glycerin, sodium lactate, and so on along with cocoa butter and dimethicone as occlusives. but i also like to add 1% beeswax. i accidentally discovered it makes the lotion last thru several hand-washings. i immediately added that to the formula for my winter cream and i love it.

Elisabeth said...

I've had very good results with Bohunk's much-lauded body mousse from the Soapdish Forum. There's quite a bit of glycerin in the formula, and the stearic acid gives it staying power. I used BTMS as an emulsifier, which I imagine also keeps the product sticking to the skin. With aloe vera and allantoin in the water phase and some light oils (I splurged on borage and pomegranate seed oils for skin repair, plus rice bran and macadamia as generals) I may be set for life.

Susan Barclay-Nichols said...

Hi Beckster! My skin is getting drier as I get older, and I'm finding that using a sugar scrub in the tub in the morning and lotions on damp skin at night really is the best for keeping the waer in my skin!

Hi Susanna! I think you saw that I answered your question as a Weekday Wondering. Short answer: No.

Hi Chris! I'm crossing my fingers!

Hi melian! Using beeswax can keep lotion on skin for longer. I should have thought of that as my favourite hand protectant contains it!

Hi Elisabeth! I love that lotion! I think it's the stearic acid that makes it longer lasting, too!

melian1 said...

susan, your comment about exfoliating is absolutely spot-on. i found with myself (dry skin in all seasons and super-dooper dry in winter), my father (85 at the time) who suffered from itchy skin especially on his back and my mom (83 at the time) who has seriously flaky skin on her legs and arms - that a nice sugar scrub or an application of a chemical scrub (refer to your series about this a couple of years ago or so) did amazing things. followed by a lovely lotion packed with humectants and occlusives, and the flakies and the itch were history. it kept all our skin in great shape.