Leshen Resin
Leshen resin is the sticky sap left behind when a leshen falls. The Witcher 3 lists it as an alchemy ingredient, but no formula actually calls for it, so its real value is what you get when you break it down.
Where to get it: Looted from leshens, including the ancient leshen, Kernun and the Woodland Spirit, and from spriggans in Blood and Wine.
Used to craft: Nothing. No potion, oil, bomb or diagram uses it.
Dismantles into: resin and monster blood.
Keep one as a reminder of a hard fight if you like, and dismantle or sell the rest.
How to obtain
Dropped by: Ancient Leshen, Leshen and Spriggan.
Keep exploring
Plan a Remastered build: skill trees, mutagens, gear and a shareable build image.
Pick a potion, decoction or bomb and see every ingredient you need.
Answer the key choices and find out which Witcher 3 ending you will get.
Every location, quest and monster in the first region on one map.
The Wolf School's hidden valley: the keep, the Bastion, caves and treasure.
Tick off every school gear diagram and crafted piece, with diagram locations.
Search any monster and see the right oil, Signs and bombs.