RSO (Rick Simpson Oil) typically produces effects that last 4 to 8 hours, making it one of the longer-lasting cannabis products available. But “how long does RSO last” can mean several things: how long the high lasts, how long it stays in your system, or how long the product remains potent on your shelf. The answer depends on which question you’re really asking.
How Long the Effects Last
RSO is a highly concentrated cannabis extract, usually containing 60% to 80% THC. A single 1 ml syringe delivers roughly 600 to 800 mg of THC, which is an enormous amount compared to a typical edible (5 to 10 mg per serving). Because of this concentration, even a rice-grain-sized dose packs a significant punch, and the effects tend to be intense and long-lasting.
How quickly you feel those effects depends on how you take it. Placed under the tongue (sublingual), RSO typically kicks in within 15 to 45 minutes. Swallowed in food or a capsule, onset takes longer, usually 30 minutes to an hour and a half. The sublingual route gets cannabinoids into your bloodstream faster through the thin tissue under your tongue, while swallowed RSO has to pass through your digestive system first.
Once the effects set in, most people feel them for 4 to 8 hours. The peak tends to hit around 2 to 3 hours in and then gradually tapers. Several factors shift this window: your tolerance, body weight, metabolism, whether you’ve eaten recently, and how large your dose was. New users or anyone taking RSO on an empty stomach will likely feel stronger, longer-lasting effects. Because RSO is so potent, starting with an extremely small amount (smaller than a grain of rice) is the standard recommendation.
How Long RSO Stays in Your System
The effects may fade after several hours, but THC metabolites linger in your body far longer. This matters if you face drug testing. Standard urine tests screen for a THC byproduct and flag anything above 50 nanograms per milliliter.
For a casual or one-time user, THC can show up on a urine test for roughly 10 days on average. Regular users typically test positive for 2 to 4 weeks, and frequent, heavy users can test positive for over a month. RSO’s high THC concentration means your body processes a larger load of cannabinoids per dose, which can push detection times toward the longer end of these ranges. Fat cells store THC metabolites and release them slowly, so people with more body fat or slower metabolisms may also test positive for longer.
Blood tests have a much shorter detection window, usually a few days at most. Hair tests can detect THC for up to 90 days, though they’re less commonly used outside of specific employment or legal situations.
Shelf Life and Storage
RSO has an exceptionally long shelf life for a cannabis product. Stored properly, it can remain potent for up to 10 years. That durability comes from its concentrated, oil-based form, which resists degradation much better than dried flower or lighter extracts.
The key to preserving RSO is protecting it from the three things that break down cannabinoids: light, heat, and air. Keep your RSO in a dark glass container, stored in a cool place like a refrigerator or a cupboard away from sunlight. The syringe packaging most RSO comes in already limits air exposure, which helps. If you live somewhere warm, refrigeration is worth it, as heat gradually converts THC into a less psychoactive compound, reducing potency over time.
You’ll know RSO has started to degrade if the color darkens significantly, the texture changes, or the effects feel noticeably weaker than when you first opened it. Even partially degraded RSO isn’t dangerous, just less effective.
Why RSO Lasts Longer Than Other Edibles
People often notice that RSO seems to hit harder and last longer than a standard gummy or brownie, even at comparable doses. Part of this is the full-spectrum nature of the extract. RSO is made using a whole-plant extraction process, meaning it contains not just THC but a broad range of other cannabinoids, terpenes, and plant compounds. These work together in what’s sometimes called the entourage effect, where the combined compounds amplify and extend the overall experience compared to products made with isolated THC.
The thick, oily consistency also plays a role. RSO absorbs more slowly through the gut than water-based or sugar-based edibles, which can spread the onset out and extend the duration. If you take RSO with a fatty meal, absorption slows further, sometimes adding an extra hour or two to the total experience.