Force alchemy, better known as Sith alchemy, was a science that referred to a number of areas under the Sith. It encompassed any power or technique which used the Dark side of the Force to permanently alter an item or living being. It is rejected by the Jedi as an act of treason against the Force’s will.
«Alchemy should have no part in a Je’daii’s experience. It is a dark force, arcane and dangerous. It has the power to upset balance. There are other ways.» ―Je’daii Temple Master Vor’Dana, 26,032 BBY.
A power related to elemental manipulation and metallurgy, Force alchemy was an ability practiced by some members of the Je’daii Order on the planet Tython. Taught at the Temple of Science, Anil Kesh, practice of alchemy required leaning into the dark side of the Force, but was deemed a permissible skill for study by the Je’daii Council. Despite this, some Je’daii questioned its practice and found it to be perverse or heretical. Je’daii Master Dam-Powl viewed her student Lanoree Brock‘s talent to genetically manipulate cells from her own body and create life, a skill called the alchemy of flesh. This skill could be used on any bit of flesh and used to manipulate other flesh, such as when Ranger Brock used skin particles to sear the memory of another person, erasing their memories by pushing the skin dust up into his brain.
At Anil Kesh, the Je’daii carried out alchemical experiments on wild beasts captured in the Abyss of Ruh, a pit deep in the heart of the Riftlands. The genetical manipulation of these animals was not done in a way that hurt or damaged the beasts, but the Je’daii believed that it was the true wish of their natural evolution that was being forwarded. Aside from alteration to living flesh, the Je’daii also used alchemical metallurgy to alter weapons both traditional and Force-based tools. Transmutation of chemicals and the restricting of solids were related abilities.