Phytosterols are analogs of cholesterol presents in plants, mainly in vegetable oils. Algaes are also a rich source of these materials and contain very specific structures, like our Fucosterol reference material. They are naturally available as aglycones, esters (fatty acids or cinnamic derivatives) or glucosides. There are many heathly benefit claims in nutrition, specially in heart disease prevention. In analytical procedure they are often titrated versus phytosterol standards by GC as volatile silylated or esterified derivatives.