Glycation is a chemical reaction mainly caused by the excess sugar in the blood, and it is one of the main causes of ageing skin. Wrinkles caused by glycation have a crosshatched-like, complex appearance, unlike the expression lines, which tend to be more horizontal.

In young healthy skin, the collagen and elastin fibres are curled. As you get older, glycation makes the collagen and elastin stick together, and the curl becomes less and loses its flexibility. This becomes more and more pronounced with age. It’s most apparent around the mouth and eyes, where the skin becomes hardened and less flexible. 

If you have high levels of blood glucose, the haemoglobin in your skin tends to darken. The glucose also attaches to proteins in places it doesn’t belong, and your skin produces advanced glycosylation end-products (AGEs). This leads to skin deterioration consistent with ageing.