Hi Dr Pickart and all,
I'd like to know if it is still necessary to apply an emu oil barrier if one is using a CP cream instead of serum? 
Also can squalane be used instead of emu as a barrier in general? 
Thanks.

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The cream itself will act as a barrier.

Oh, excellent!

What about Squalane as a barrier for serums? As it is a lighter oil, is it a good enough barrier?

Squalane will also work. Oils that penetrate the skin tend to stay there for a time and will block other materials from entering the skin.

Dr Pickart,

I understand that uncoated zinc oxide (I'm referring to non-nano ones of above 100nm particle size) is better because coated ones slip into the skin. However, I am concerned about the uncoated ones generating more free radicals and inflicting more damage on the skin than the coated ones. What's your advice on this?

The problem with the coated products is that they build up in the lower levels of the skin. They uncoated ones penetrate less and stay more on the skin's surface.

Free radicals on the skin's surface cause little damage since the surface is just dead protein but within the skin they can damage the sensitive cells of the skin.