Are skin boosters effective for internal dryness?

I heard that it is more effective for inner dryness than for the surface skin.

Since I have tightness deep inside, my outer skin must be dry too, so I guess it's basically the same thing...

There are quite a few reports that skin tightness has decreased after washing, so I am very interested in this procedure, wondering if the moisturizing effect is significant.

Are skin boosters effective for inner dryness rather than outer skin?