What is Full Spectrum Oil? Full Spectrum Oil, also known as FSO, is a concentrated cannabis extract that is similar to most distillates. The difference lies in the refinement process and the final product. Most distillates go through a complicated refining process that strips the plant material down to one or two active cannabinoids (typically THC & CBD) and a formulated terpene profile. FSO, on the other hand, is processed in a way that keeps the plant’s natural profile intact. While your average distillate will contain all of the cannabinoids and terpenes that make a strain or formula beneficial, FSO contains those plus the flavonoids, fatty lipids, phenols and other naturally occurring components found in the cannabis plant. The end result is an extract that is thicker, darker and more potent than a refined distillate, and packed full of the same potential whole plant benefits that you could expect from more traditional products like smokable flower.