The present invention provides a granule powder product containing a minimum of 25% Hydroxytyrosol, and a method of making such a product. The product is made from cultivated olive leaves. Because of unique production and purification technology provided by the present invention, Oleuropein present in the olive leaf extract is essentially completely transferred into Hydroxytyrosol by a biotransformation process. As a result, essentially no Oleuropein residue is present in the final product.
