RSO oil is a thick, dark cannabis extract made by soaking cannabis plant material in a solvent and then evaporating the solvent to leave a concentrated resin. It gets its name from Rick Simpson, a Canadian who popularized the method in the 2000s. Most RSO carries high levels of THC, which separates it from the CBD oil sold in mainstream US stores.
What Is RSO Oil?
RSO is a full-extract cannabis oil, not a single isolated compound. The process pulls out cannabinoids, terpenes, waxes, and other plant compounds together, which gives the finished product a tar-like texture and a strong plant taste.
Marijuana RSO Oil: What It Is and How It Compares to CBD
- Also called: Rick Simpson Oil, RSO, Phoenix Tears.
- Appearance: Thick, sticky, dark green to near-black.
- Main cannabinoids: THC in most batches, with smaller amounts of CBD and other cannabinoids.
- Strength: Concentrated, often well above the THC level of dried flower.
How Is RSO Oil Made?
The traditional method uses a solvent to strip cannabinoids from the plant. The solvent is then evaporated, and gentle heat converts acidic cannabinoids into their active forms in a step called decarboxylation.
- Cannabis buds are dried and sometimes ground.
- Plant material is soaked in a solvent such as ethanol or naphtha.
- The liquid is strained away from the plant matter.
- The solvent is evaporated, leaving a thick oil.
- Gentle heat finishes the extract and activates the cannabinoids.
Rick Simpson's original instructions used naphtha, a petroleum solvent that is hard to remove without lab equipment. Home production with flammable or toxic solvents is dangerous and can leave residue in the final oil. Producers who follow state rules use closed-loop equipment and test each batch for residual solvents.
Understanding Cannabis RSO: A Comprehensive Guide
RSO Oil vs CBD Oil: What Is the Difference?
RSO and CBD oil sit at opposite ends of the cannabis spectrum. CBD oil comes from hemp, holds no more than 0.3% THC under federal law, and does not cause a high. RSO comes from high-THC cannabis and does cause intoxication.
- Source plant: CBD oil comes from hemp. RSO comes from high-THC cannabis.
- THC level: CBD oil stays at or below 0.3%. RSO can run far higher.
- Legal status: Hemp CBD is legal at the federal level. RSO is not.
- Effect: CBD is non-intoxicating. RSO produces a strong high.
Some shoppers search for an "RSO CBD oil" that carries no THC. No standard product by that name exists. If a label sells an RSO-style oil with zero THC, it is a different extract, and the label deserves a close read.
Does RSO Oil Have Medical Uses?
Research on cannabis extracts exists, but it centers on cannabinoids in general rather than on RSO as a defined product. The FDA has approved no RSO product for any condition, including cancer. Claims that RSO treats or cures cancer are not supported by clinical trials in humans.
What studies do look at is symptom relief:
- Nausea and vomiting from chemotherapy.
- Appetite loss and weight loss in some conditions.
- Chronic pain, including nerve pain.
- Rare childhood epilepsy syndromes, though the approved drug for this is a purified CBD product, not RSO.
Because RSO batches vary in THC and other compounds, dosing is hard to repeat. A patient who gets a different batch gets a different dose.
Is RSO Oil Legal in the US?
Under the federal Controlled Substances Act, cannabis with more than 0.3% THC is a Schedule I drug. That makes RSO illegal under federal law in every state. Many states allow it through medical cannabis programs, and some allow it for adult use as well.
Hemp-derived CBD with no more than 0.3% THC is legal at the federal level under the 2018 Farm Bill. Crossing state lines with RSO remains a federal offense even when both states allow cannabis. Buying RSO from an unlicensed seller also skips the lab testing that state programs require.
How Do People Use RSO Oil?
RSO is swallowed, placed under the tongue, or rubbed on the skin. The classic Rick Simpson routine builds from a dose the size of half a grain of rice up over several weeks, though no standard dose exists.
- Start with a small amount and wait at least two hours before taking more.
- Take it with food if it upsets your stomach.
- Do not drive or use machinery after a dose.
- Talk to a clinician first if you take prescription drugs or have a heart condition.
Risks and Side Effects of RSO Oil
RSO can cause strong intoxication, drowsiness, anxiety, fast heartbeat, and confusion. These effects hit harder in people who do not use THC. Oil and edible doses also take longer to peak than inhaled cannabis, so it is easy to take too much.
Two other risks matter. Poorly made RSO can carry residual solvents, pesticides, or mold. THC can also interact with blood thinners, sedatives, and other medications. Pregnant people, children, and anyone with a history of psychosis should avoid THC-heavy extracts.
FAQ
Is RSO oil the same as CBD oil?
No. RSO comes from high-THC cannabis and causes a high. CBD oil comes from hemp, holds no more than 0.3% THC, and does not intoxicate.
Does RSO oil get you high?
Yes, in most cases. The THC level in RSO is high enough to produce a psychoactive effect.
Can you buy RSO oil online?
Not from a licensed US seller. Federal law bars shipping high-THC cannabis products across state lines. Products marketed as RSO on random websites are often mislabeled or hold no THC at all.
How should RSO oil be stored?
Keep it in a cool, dark place in a sealed container. Heat and light degrade cannabinoids and turn the oil harsh.
What should I check on a lab report?
Look at the THC and CBD percentages, the solvent residue panel, and the pesticide and microbial results. A certificate of analysis from an accredited lab covers all of these. Lab-tested CBD products should meet the same standard, and any seller who cannot show a report is one to skip.