The Pilgrim Apothecary

At the request of God, a Japanese salaryman, Toudo Yuuki was transported into another world as practice for the actual Hero’s summoning. And now, he lives as the herbalist, Shin. Making use of his past knowledge, he concocts powerful potions and travels the world selling them. However, due to its potency, he was drawn into a certain country’s conspiracy. But, they did not know. That despite his outward appearance of a good-willed person, he in fact held the strength to slay even a dragon.
Source: AlphaPolis