Yves Saint Laurent Forever Youth Liberator SerumBeauty by Mrs C - January 3, 2012Yves Saint Laurent's Forever Youth Liberator Serum is a new skincare product which, according to the 'blurb' anyway, is based on on glycobiology.It seems that the sciencey bods at Yves Saint Laurent have discovered that as we get older the number of glycans in our skin diminishes. Apparently this leads to the cells 'locking' and and consequently delays the skin's regeneration. Yves Saint Laurent say