They have alchemy as a self employed career. My sim had the opportunity to join the alchemy career. She went to the court house and registered and she has been listed as self-employed, open work hours. She is supposed to make elixers to sell (amount wasn't note) and I am not sure about the rest of the requirements. I'll check in the careers and see what it says.
I think they need to do that with all of the self-employed careers, authors, artists, gardeners and fishing.