Rick Simpson Oil (RSO)
Definition: Rick Simpson Oil (RSO) is a thick, dark, highly concentrated cannabis oil made by soaking whole cannabis flower in a solvent and evaporating the solvent off. It’s usually very high in THC and taken by mouth in tiny, rice-grain-sized doses. It’s named after Rick Simpson, a Canadian who popularized it in the early 2000s and claimed it treated his skin cancer.
How Is RSO Made?
Traditional RSO soaks ground cannabis in a solvent such as ethanol or, in Simpson’s original method, naphtha. The plant material is strained out and the solvent is evaporated with low heat, leaving a tar-like full-extract oil. Because the heating also decarboxylates it, RSO is active when eaten. Home production is risky: these solvents are highly flammable, and poorly evaporated solvent can remain in the oil. Licensed versions, often sold in oral syringes, are lab-tested.
How Strong Is RSO?
Very. RSO is a whole-plant concentrate that keeps most of the plant’s cannabinoids, often with high THC. Because it’s usually swallowed or placed under the tongue, it behaves like an edible: slow to kick in and long-lasting. Start with a very small amount and wait at least two hours before taking more.
Does RSO Cure Cancer?
There’s no reliable evidence that it does. According to the National Cancer Institute, no studies of cannabis as a treatment for cancer in people have been found, and cannabis has not been approved to treat cancer. Lab and animal studies on cannabinoids and tumor cells exist, but they don’t show that RSO cures cancer in humans. The FDA has approved cannabinoid drugs like dronabinol and nabilone only to manage chemotherapy-related nausea and vomiting. Anyone with cancer should not delay or replace proven treatment with RSO and should talk to their oncology team before using cannabis.
Related terms: Concentrates, Canna Oil, MMJ, Edibles
Sources: National Cancer Institute: Cannabis and Cannabinoids (PDQ); NIDA: Cannabis Concentrates DrugFacts.
This entry is for general education and isn’t medical advice.
