Generally, aging process begins from 25 years old. Before 20s, skin color returns rapidly after the summer suntan. But those over 25 need more recovery time and melasma and freckle appears. Therefore whitening treatment is recommended for those who are around 25 years old. Conventional method of whitening was decreasing activity of melanocyte by blocking sun or making pigment dimmed. Recently, new method has been introduced that removes pigment producing cell.

In the skin exposed to ultraviolet, protein changed to brown color by combined with unnecessary glycogen. This phenomenon called glycation makes skin dark yellowish color and rough. Recently whitening procedure blocks denaturalization of protein to brighten skin.