Elana inquires: Just wondering – if all sorts of cones + glycerine are up in the ingredients list and then followeb by other ingredients like vitamins, peptides, natural oils etc., won’t they prevent the later from penetrating the skin, thus not making any positive effect by staying on the surface? I have this perception (maybe the wrong one) that silicones sort of coat skin surface, not letting anything in or out. Then if they are on top of the list, other ingredients should be useless… I looked through your wonderful site but only seem to find info about silicones in the context of hair products. But hair is dead and skin is a live organ, so the effect of cones on it might be different? Please correct me if i am wrong. why i am asking… I color my hair at home using brown or dark brown shades. They stain skin around my hair line. I experimented with applying all sorts of moisturising creams near the hair line beforehand and SURPRIZE – those with cones (like Olay) work the best in keeping stains away. Sooooo, if you stuff a cream with all sorts of goodies for the skin and then go generous on cones for better feeling and gliding application, won’t they prevent all the goodies from absorbing, just like they prevent hair color sinking in the skin?… hmmm
The Right Brain responds:
I haven’t seen a definitive technical answer for this but here’s what I THINK happens:
Silicone forms a barrier
When you apply a cream containing “goodies” along with silicones, the cream hits the face all at once, the ingredients that will penetrate have time to sink into the skin before all the water evaporates and the silicones set up an occlusive film. When you apply a silicone cream FIRST and then sometime later apply another product (like a hair color) the silicones have had time to set up as a film and so they do a better job of keeping stuff OUT of the skin. Hence, no staining.
Image credit: http://13thstreetstudio.typepad.com/
{ 10 comments… read them below or add one }
Interesting read. I always wondered this myself
I kinda like the Cosmetic Cop’s assessment that cones are like “tea bags” which let beneficial ingredients “seep” through.
Anyhow, I never noticed a negative impact on the activity of the niacinamide & glucosamine in my DIY cream after I started adding dimethicone to it. (I know that’s an anecdotal example, but still!)
Does that mean that if you apply a serum with a high silicone content, then a moisturiser, it will prevent the moisturiser from penetrating the skin?
@SK: Yes, that’s possible. But that doesn’t mean the moisturizer won’t work. Most moisturizing ingredients work at the surface anyway.
I like your assesment, Brains, though it would be cool if someone could make the scientific research on this one. Also, if ingredients hit skin all at once, they need to be very quick runners to upbeat cones, since i notice cone shield forms fast!
do all sorts of ingredients have the same absorbation time?
Also, why do they need to put cones to make an emulsion feel soft and pleasant? why not put, say, hyaluronic acid (or sodium hyalurobate)? it also feels good to skin, forms a layer and gives additional moisture…
@Elena44 I’d love if Beauty brains could answer your question because you brought up a great point!
Please answer Beauty Brains!
@Chi and Elena44: Hylauronic acid does not form the an occlusive shield like dimethicone does. Therefore it will allow more water to evaporate through the skin.
Do we really need this occlusive shield if we consume enough liquid throughout the day?
what about natural oils instead of silicones?
It doesn’t matter how much water you drink if you’re losing too much moisture through your skin. Natural oils help they’re just not as good as silicone or petrolatum.
Hm… Maybe if i live in Sakhara for too long, i’d agree. In other cases skin has to manage this by itself, hasn’t it? After all, we have oil coming out and use blotting sheets