The problem with the recipes (The Witcher 3: Wild Hunt)

Good day ! The problem with the recipes. I wanted to improve the silver sword school of the bear , needed ingredient Nigredo. I read in the Internet one, and where to buy it, went to all herbalists , merchants, and made sure that not one of them sold out alchemical recipes, in sales there are only recipes for runes and glyphs. So, I was wondering, is it a bug in my game or does it depend on the storyline ? Greist and other merchants who need to sell magical alchemical recipes sell only herbs and recipes for runes and glyphs . How to deal with this problem , someone tell me ?