Rick Simpson Oil (RSO) typically stays detectable in your system for 3 to 21 days in urine, depending on how often you use it. RSO is a highly concentrated cannabis extract with very high THC levels, so it delivers a larger dose of THC per use than most other cannabis products. That said, drug tests don’t look for RSO specifically. They detect the same THC byproducts that any cannabis product leaves behind, and the detection window depends on the type of test, your usage pattern, and your body composition.
Why RSO Takes Longer to Clear Than Smoking
When you eat or swallow RSO, your liver processes the THC before it reaches your bloodstream. This creates a potent metabolite that is more active than THC itself and takes longer for your body to break down. Smoked cannabis bypasses much of this liver processing, which is why edible forms tend to produce longer-lasting effects and leave detectable traces for a longer period.
RSO compounds the issue because of its concentration. While a typical cannabis flower might contain 15 to 25 percent THC, RSO is a full-extract oil designed to pack as much THC as possible into a small dose. More THC going in means more metabolites your body needs to eliminate, which stretches the clearance timeline.
Your body excretes roughly 80 to 90 percent of a THC dose within five days, according to CDC data. About 20 percent leaves through urine and 65 percent through feces. But the inactive byproduct that urine drug tests detect can linger in your system well beyond that five-day window, especially with repeated use.
Detection Windows by Test Type
Each type of drug test has a different sensitivity and looks back over a different time period. Here’s what to expect:
- Urine tests: The most common screening method. A single use is typically detectable for 3 to 4 days at the standard cutoff level, and up to 7 days at a more sensitive cutoff. Chronic users can test positive for up to 21 days after stopping, even at low cutoff thresholds. With a high-potency product like RSO used regularly, you should plan for the longer end of that range.
- Saliva tests: These detect THC for up to 24 hours after use. Saliva testing has a short window and is generally used to identify very recent consumption rather than habitual use.
- Blood tests: THC itself clears the bloodstream relatively quickly, usually within a day or two for occasional users. However, the metabolites can persist longer, particularly after oral ingestion, because the liver processes THC more slowly when it comes through the digestive system.
- Hair follicle tests: Hair testing can reveal a pattern of repeated drug use going back up to 90 days. This is the longest detection window of any standard test, and frequent RSO use would almost certainly show up within that timeframe.
How Your Body Stores and Releases THC
THC is fat-soluble, meaning it dissolves into your body’s fat tissue rather than washing out quickly through water-based fluids. Each time you use RSO, a portion of the THC gets stored in fat cells. Over time, that stored THC slowly releases back into your bloodstream, where your liver breaks it down into the metabolites that drug tests detect.
This creates an important and sometimes surprising effect: stress and food deprivation can temporarily increase THC levels in your blood. Research has shown that anything triggering your body to burn fat, including fasting and stress hormones, enhances the release of stored THC back into circulation. In animal studies, this was significant enough that researchers described it as a kind of “reintoxication,” where THC levels rose without any new cannabis use.
This is why people with higher body fat percentages tend to retain detectable THC levels for longer. There’s simply more storage space for the compound to accumulate, and it takes more time for the body to cycle through all of it.
Factors That Affect Your Personal Timeline
No two people clear THC at the same rate. The biggest variables are:
- Frequency and quantity of use: Someone who takes RSO daily for weeks will carry metabolites far longer than someone who tried it once. Daily users should expect to test positive for two to three weeks after their last dose.
- Body fat percentage: More fat tissue means more THC storage and a slower release curve. Leaner individuals generally clear THC faster.
- Metabolism and eating habits: A faster baseline metabolism processes and eliminates THC byproducts more quickly.
- Exercise: Physical activity can release stored THC from fat cells into the bloodstream. A 2013 study confirmed that exercise causes measurable increases in blood THC levels as fat is burned. This means working out could temporarily make you more likely to test positive, even though it helps clear THC from your body over time.
Because RSO delivers such a concentrated dose, the “quantity of use” factor carries extra weight here. Even occasional RSO use delivers more THC per session than most other cannabis products, so your body has more metabolites to process after each dose.
What This Means for Drug Testing
If you’re facing a urine test and you’ve used RSO once or twice, a window of 4 to 7 days is a reasonable expectation, though some people clear it in 3 days. If you’ve been using RSO regularly, plan for at least 21 days. Some heavy, long-term users of high-potency cannabis report positive tests beyond that range, though clinical data suggests 21 days is the upper boundary for most people at even the most sensitive cutoff levels.
For hair tests, the math is different entirely. Since hair grows about half an inch per month and labs typically test the most recent 1.5 inches of growth, any regular RSO use within the past 90 days is likely to show up. There is no reliable way to speed up this particular detection method.
Exercising in the days immediately before a urine test is worth thinking about carefully. While staying active generally supports faster metabolism, the acute release of stored THC during a workout could raise your metabolite levels right before the test. If you’re cutting it close on timing, intense exercise the day before a screening could work against you.