Rick Simpson Oil (RSO) typically contains 60% to 80% THC, making it one of the most potent cannabis products available. A single 1 ml syringe of RSO delivers roughly 600 to 800 mg of THC, which is enough to produce intense, long-lasting effects even for experienced cannabis users.
RSO Potency Compared to Flower and Edibles
To put RSO’s strength in perspective, standard cannabis flower contains 15% to 30% THC. RSO concentrates that same plant material into an oil that is three to five times stronger by weight. A typical cannabis edible sold at a dispensary contains 5 to 10 mg of THC per serving. A rice-grain-sized drop of RSO, the commonly recommended starting dose, contains 18 to 24 mg of THC. That tiny drop is already two to four times stronger than a standard edible gummy.
Some lab analyses of crude ethanol extracts like RSO place THC concentrations in the 40% to 60% range rather than the higher end, depending on how much plant material (particularly chlorophyll) was pulled into the oil during extraction. This is why RSO has its characteristic dark green or black color. The chlorophyll and other plant compounds dilute the overall cannabinoid percentage but don’t reduce the total amount of THC in the syringe. A darker, lower-percentage RSO simply means more non-cannabinoid material came along for the ride.
What Makes RSO a Full-Spectrum Extract
RSO isn’t pure THC. It’s a full-spectrum oil, meaning it retains a wide range of compounds from the original plant. Alongside THC, RSO contains smaller amounts of CBD, CBG, CBN, CBC, and other minor cannabinoids, plus terpenes and plant waxes. These additional compounds can influence the overall experience, potentially softening or shaping the effects of THC in ways that a pure THC distillate would not.
The solvent used in extraction affects what ends up in the final product. RSO is traditionally made with ethanol, which the FDA considers safe for consumer goods. Ethanol pulls cannabinoids efficiently but also extracts chlorophyll and other polar compounds, contributing to RSO’s dark appearance and slightly bitter taste. Some older recipes called for isopropyl alcohol, which extracts even more chlorophyll and is significantly more toxic if residual solvent remains in the finished oil. Methanol, another alternative, is less efficient at extracting THC and poses serious health risks. For these reasons, food-grade ethanol is the standard for any RSO worth using.
How the Effects Feel and How Long They Last
Most people take RSO orally, either swallowed directly or placed on food. When swallowed, the oil passes through your digestive system and is processed by the liver, which converts THC into a metabolite that crosses into the brain more readily and produces stronger, longer-lasting effects than smoking or vaping the same amount of THC. This is the same mechanism that makes edibles hit harder than flower, but RSO amplifies it because the dose per drop is so much higher.
Onset takes 45 minutes to 2 hours when swallowed. If you place RSO under your tongue instead, effects can begin within 15 to 45 minutes because some of the THC absorbs directly into the bloodstream through the tissue there. Either way, the effects of oral RSO last considerably longer than inhaled cannabis, often persisting for 4 to 8 hours, with some users reporting residual grogginess the next morning at higher doses.
Why Dosing RSO Requires Caution
The standard starting dose is a drop roughly the size of a grain of rice, about 0.03 ml. Even at that small volume, you’re consuming 18 to 24 mg of THC, a dose that would overwhelm most people who don’t use cannabis regularly. For context, many regulated cannabis markets define a single serving as 5 or 10 mg of THC.
Taking too much RSO won’t cause a fatal overdose, but the experience can be deeply unpleasant. Research on high-potency THC products shows that acute effects of excessive doses include confusion, sedation, anxiety, dysphoria, and significant impairment to attention and coordination. These negative effects are dose-dependent, meaning the more THC you consume, the more likely and more intense they become. People who start with RSO as their first cannabis product are at particular risk of overconsumption simply because a small measurement error with a syringe can double or triple the intended dose.
Risks of Regular High-Potency Use
Beyond individual dosing sessions, regular use of high-potency THC products like RSO carries its own set of concerns. Research published in the National Library of Medicine found that higher-potency cannabis is associated with faster tolerance buildup, greater physical dependence, and more pronounced withdrawal symptoms when stopping. One study found that using high-potency products from the start of cannabis use was correlated with four times the risk of developing problematic use patterns within the first year.
Longer-term effects observed in research include mood instability, increased irritability, and depressed mood. There is also a body of evidence linking sustained high-potency cannabis use to elevated risk of psychotic symptoms, particularly in individuals with a personal or family history of psychotic disorders. These risks scale with potency and frequency, which makes RSO a product that rewards careful, intentional use rather than casual experimentation.
Reading RSO Labels at a Dispensary
In regulated markets, RSO sold at dispensaries must undergo potency testing before reaching shelves. Labs analyze the cannabinoid profile and report total THC and CBD content, along with THC-A and CBD-A (the raw, unheated forms of those cannabinoids). The label on your RSO syringe should list total THC for the entire package, and sometimes per dose. If the label only shows a total for the full syringe, divide by the number of milliliters to estimate per-dose strength. A 1 ml syringe testing at 70% THC contains 700 mg total, so each rice-grain drop (0.03 ml) delivers about 21 mg.
Potency can vary meaningfully between batches and brands. Two RSO syringes sitting next to each other on a dispensary shelf might differ by 20 percentage points or more, which translates to hundreds of milligrams of THC per syringe. Always check the lab results on the packaging rather than assuming every RSO product is the same strength.