RSO, or Rick Simpson Oil, is a full extract cannabis oil. It is made by soaking cannabis plant material in a solvent, then evaporating the solvent. The result is a thick, dark oil with high THC content. RSO is not a standard product. Potency, color, and texture change from batch to batch. In the US it is sold in state-licensed cannabis stores, not in pharmacies. No cannabis product is FDA approved to treat cancer.
RSO Syringe Strength and Effects: What to Check Before You Buy
What "Full Extract" Means
Most cannabis oils sold in vape cartridges use distilled THC. Distillation strips out plant compounds and leaves a clear, high-purity oil. Full extract oil keeps more of the plant. The solvent pulls cannabinoids, terpenes, waxes, chlorophyll, and other molecules. That mix is why the oil looks dark green or black and tastes bitter. THC content in tested RSO samples runs from about 50% to 90% by weight. CBD, CBG, and other cannabinoids appear at lower levels, based on the starting plant.
How RSO Is Made
- Dry and grind cannabis flower.
- Soak the plant material in a solvent. Common solvents: ethanol, isopropyl alcohol, naphtha.
- Strain the liquid from the plant matter.
- Evaporate the solvent with low heat or a vacuum chamber.
- Heat the remaining oil to activate THC through decarboxylation.
Solvent choice changes the final product. Ethanol is the most common solvent in licensed US production. Naphtha and isopropyl alcohol carry higher residue risk when the purge step is incomplete. State labs test for residual solvents, pesticides, and heavy metals. Ask for a batch test report.
How People Use It
- Oral: swallow the oil, or place it on food.
- Sublingual: hold it under the tongue.
- Topical: rub it on the skin.
RSO is not made for vaping or dabbing. It contains plant waxes and possible solvent residue. Heating it for inhalation adds risk.
Dosing
RSO is strong. A single drop can hold 25 mg of THC or more. Start with a dose the size of a grain of rice, cut in quarters. That is about 5 mg to 10 mg of THC. Wait two hours before taking more. Oral cannabis takes 30 minutes to 2 hours to peak. Effects last 4 to 8 hours. New users should start below 5 mg. THC can cause anxiety, rapid heart rate, and impaired coordination. Do not drive after a dose.
Legal Status in the US
Cannabis is illegal under federal law. It sits on Schedule I of the Controlled Substances Act. As of 2024, 38 states and the District of Columbia allow medical cannabis. 24 states allow adult use. RSO is sold inside those state programs. Rules on THC limits, packaging, and possession differ by state. Crossing state lines with RSO is a federal offense. Do not carry it on a plane.
What Research Shows
Lab studies show cannabinoids can kill cancer cells in dishes and in mice. Human trials have not shown that cannabis cures cancer. The National Cancer Institute states there is no evidence that cannabis or cannabinoids cure cancer in people. The FDA has not approved any cannabis product to treat cancer, and it has sent warning letters to companies that make that claim. Approved cannabis-related drugs include dronabinol and nabilone for chemotherapy-induced nausea, and cannabidiol for certain seizure disorders. All three are prescription drugs. None is RSO.
Storage and Safety
Keep RSO in a glass syringe or a sealed glass jar. Store it in a cool, dark place. Heat and light degrade THC over time. Keep it away from children and pets. A child who swallows RSO needs emergency care.
What to Check at Purchase
- Batch test results for potency and solvents.
- Total THC and total CBD in milligrams per gram.
- Harvest and packaging dates.
- State compliance label.