Products derived from the Tripterygium wilfordii Hook F (TwHF) plant in the form of extracts are provided that are useful in preventing, treating, or ameliorating a symptom of an inflammatory disorder or an immune disorder, such as an auto-immune disease. Also provided are methods of freeze-drying a TwHF root and/or root portion, methods of debarking a freeze-dried TwHF root and/or root portion, methods of preparing and/or refining extracts in freely flowable solid form from freeze-dried debarked TwHF roots and/or root portions, and methods of using freely flowable solid extracts of TwHF in preventing, treating or ameliorating a symptom of an inflammatory disorder and/or an immune disorder.
