The Help's Viola Davis looked positively stunning at the 2012 Oscars -- and although she got her makeup done by a pro, there's no mistaking her ageless, radiant complexion peeking out from underneath.

When it comes to nixing dull skin, many think the only option is to slough it off with a face scrub -- a physical exfoliant. And while a gritty formula may be the answer for quicker skin cell turnover, it can be harsh on sensitive skin types.

In the video above, celeb dermatologist and Physician's Formula consulting doc Meghan O'Brien debunks the difference between physical and chemical exfoliants, plus the formula you should be using now.