RSO is a full spectrum plant extract of potent cannabis. It therefore contains very high levels of THC, CBD and other cannabinoids such as CBN and CBG. In 2003, Rick Simpson was diagnosed with basal cell carcinoma and used cannabis oil to cure his skin cancer. Since then he has become one of the biggest advocates for cannabis oil in the US. Rick Simpson does not supply the cannabis oil himself, but has made his techinque available to ensure that everyone is producing the oil properly. Alcohol extraction involves steeping cannabis plant matter in food-grade alcohol until the plant’s active ingredients have transferred into the solution. Cannabis’ active ingredients are called cannabinoids and are situated inside microscopic external plant glands called trichomes. Trichomes have a mushroom shape and waxy coating, and do not dissolve into water. However, trichomes do dissolve into liquids with oil-like properties, including alcohol. Alcohol is an organic compound often created by fermentation, as in common alcoholic beverages like beer, wine and spirits. Typically, alcohol extracts are made by placing raw cannabis plants into a container filled with pure, food-grade alcohol. Over a matter of days and weeks, the cannabinoids dissolve into the alcohol. Forms of light agitation like stirring and turning — as well as heat — are sometimes used to enhance the process. The results of alcohol-based extraction are a tinted liquid alcohol solution containing the active ingredients from the raw plant — the cannabinoids. This alcohol extract can then be further screened for particulates, refined, diluted or distilled.

via sparcsf.org