Photo: RNZ/Carol Stiles The grease which is a by-product of wool scouring is used in cosmetics, skincare and medicines. New Zealand wool is high in cholesterol which can then be turned into vitamin D. The vitamin is in Covid-19 vaccines which is increasing demand for wool grease. WoolWorks New Zealand is the only company in the country that produces and exports wool grease. Its chief executive Nigel Hale said with global demand increasing prices were going up too. "There's a growing awareness of the value of wool grease and the products it can be turned into. "The worldwide population of sheep is not increasing, in fact, it's probably decreasing slightly so with worldwide demand for wool grease products growing and the sheep population declining there's obviously going to be a move in price," Hale said.