RSO vs FECO: Understanding the Differences and Benefits
RSO vs FECO: What's the Difference? | Green Health Eugene
If you’ve been browsing our menu on Highway 99 and wondering about the difference between RSO (Rick Simpson Oil) and FECO (Full Extract Cannabis Oil), you are not alone. These are two of the most potent, medicinal-grade concentrates on the market, yet they are often confused.
For our medical patients and recreational customers in West Eugene looking for serious relief from chronic pain, insomnia, or inflammation, understanding this difference is key. While both are full-spectrum, whole-plant extracts, the way they are made—and how you should take them—varies.
Quick Comparison: RSO vs. FECO
Solvent Used
RSO: Traditionally made with Isopropyl Alcohol or Naphtha.
FECO: Made with Food-Grade Grain Alcohol (Ethanol) or CO2.
Color & Texture
RSO: Dark, thick, tar-like black oil.
FECO: Lighter, amber-to-dark oil; often stickier but smoother.
Flavor Profile
RSO: Strong, bitter, plant-heavy (chlorophyll taste).
FECO: Earthy but generally cleaner and less bitter than RSO.
Best Used For
RSO: Heavy sedation, cancer symptom management, deep sleep.
FECO: Daily medical use, oral dosing, sensitive stomachs.
Can You Smoke It?
RSO:NO. (Contains plant fats/lipids—harsh on lungs).
FECO:NO. (Edible/Topical use only).
From the Counter: The Budtender’s Take
"I always tell people: treat these oils with respect. They are not like eating a 10mg gummy. RSO and FECO are 'whole plant' medicine, so you get all the heavy, sedative effects of the plant fats and waxes. Start with a tiny drop—literally the size of a half-grain of rice. You can always take more, but you can't take less!" — Jed, Green Health Team
What is RSO (Rick Simpson Oil)?
Named after the Canadian medical cannabis activist Rick Simpson, RSO is the original heavy-hitter concentrate. Simpson created it to treat his own skin cancer, and it gained a cult following for its reported anti-inflammatory and sedative properties.
How it’s made: Whole cannabis flowers are soaked in a strong solvent (like isopropyl alcohol) to strip the cannabinoids. The solvent is then boiled off, leaving behind a thick, black, tar-like oil.
The Vibe: RSO is famously unrefined. It retains a lot of chlorophyll and plant waxes, giving it a bitter taste but a "heavy" body feel that many chronic pain patients prefer.
What is FECO (Full Extract Cannabis Oil)?
FECO is the modern evolution of RSO. The goal is the same—a potent, full-spectrum oil—but the method is often gentler.
How it’s made: FECO is typically extracted using food-grade grain alcohol (Ethanol) or CO2. Because these solvents are safer for human consumption than isopropyl alcohol, many medical patients prefer FECO for daily oral use.
The Vibe: FECO often retains more of the original terpenes and flavor of the strain, offering a slightly cleaner experience while still delivering that "whole plant" potency.
How to Dose RSO & FECO (The "Rice Grain" Rule)
Because these oils can test upwards of 70-80% THC, dosing is critical.
Squeeze a tiny amount onto a cracker, piece of chocolate, or hard candy.
Size Matters: Aim for a dose the size of a grain of rice (approx. 25-50mg). If you are new to extracts, start with half a grain of rice.
Wait: Like any edible, it can take 90 minutes to 2 hours to kick in.
WARNING: Do not dab or smoke RSO or FECO. These oils contain plant lipids, fats, and chlorophyll that are safe to eat but can be harsh and harmful to your lungs if vaporized.
The Entourage Effect: Why Full-Spectrum Matters
Both RSO and FECO are full-spectrum extracts, meaning they contain the complete range of cannabinoids (THC, CBD, CBN, CBG, CBC), terpenes, flavonoids, and plant waxes found in the original flower. This is important because these compounds work together in what researchers call the entourage effect — a synergy where the combined action of all compounds produces stronger therapeutic results than any single cannabinoid alone.
This is why a 70% THC RSO syringe often feels more sedative and "body-heavy" than a 90% THC distillate cartridge. The distillate has been stripped of everything except THC, while the RSO retains the full plant profile that drives deeper relief.
Does FECO or RSO Get You Stoned?
Yes — both RSO and FECO are extremely psychoactive. A single syringe can contain 600–800 mg of THC, which is the equivalent of 60–80 standard edible doses. Even a grain-of-rice-sized serving delivers roughly 25–50 mg of THC, which is 2.5–5× the standard Oregon recreational dose of 10 mg.
The "high" from RSO and FECO feels different from smoking flower or eating a gummy. Because these are full-spectrum oils with high concentrations of plant waxes, CBN, and myrcene-heavy terpenes, the effect is typically:
- Heavy body sedation within 60–120 minutes
- Pronounced couch-lock and drowsiness
- Deep, uninterrupted sleep (the most common medical use)
- Strong appetite stimulation
FECO tends to feel slightly "cleaner" than RSO because the ethanol extraction preserves more terpene diversity, but both will absolutely produce strong psychoactive effects. Do not drive or operate machinery after taking either product.
Is RSO Stronger Than Other Concentrates?
It depends on what you mean by "stronger." In terms of raw THC percentage, RSO (60–80% THC) is actually lower than live resin (70–90%), shatter (80–95%), or distillate (85–99%). But in terms of felt intensity and duration, RSO and FECO often hit harder because:
- They are eaten, not smoked — oral THC converts to 11-hydroxy-THC in the liver, which crosses the blood-brain barrier more efficiently and lasts 4–8 hours instead of 1–2
- The full-spectrum plant profile amplifies the entourage effect
- Plant waxes and fats slow absorption, creating a longer, deeper experience
So while a dab of live resin might test higher on paper, a rice-grain of RSO taken orally will usually produce a longer, more sedative experience. For chronic pain patients, this sustained release is exactly the point.
Solvent Safety: Why Extraction Method Matters
This is where RSO and FECO diverge most sharply, and it is the single most important factor for medical patients choosing between them.
RSO (Isopropyl Alcohol / Naphtha)
Rick Simpson's original method calls for soaking cannabis in isopropyl alcohol (IPA) or naphtha — industrial solvents that are effective at stripping cannabinoids but are not food-grade. If the purge process is incomplete, trace amounts of these solvents can remain in the final oil. In Oregon, OLCC-licensed producers must test for residual solvents, but traditionally made RSO (especially out-of-state or homemade) may not meet these standards.
FECO (Ethanol / CO₂)
FECO is extracted using food-grade grain alcohol (ethanol) or supercritical CO₂. Both solvents are recognized as safe for human consumption by the FDA. Ethanol extraction also preserves a broader terpene profile because it can be performed at lower temperatures, reducing heat degradation.
⚠ Safety Warning: Never attempt to make RSO or FECO at home. Both isopropyl alcohol and ethanol are highly flammable. Home extraction has caused fires, explosions, and serious injuries. Always purchase lab-tested products from a licensed Oregon dispensary.
When to Choose RSO vs. FECO
Choose RSO If You:
- Need maximum THC for severe pain or cancer symptom management
- Prefer a heavy sedative effect for deep sleep
- Have experience with high-dose edibles and know your tolerance
- Are following a specific RSO protocol (e.g., the "Rick Simpson Protocol")
Choose FECO If You:
- Want a cleaner extraction method with food-safe solvents
- Prefer a balanced cannabinoid profile (CBD + THC ratios available)
- Are using cannabis for daily medical maintenance (inflammation, anxiety, appetite)
- Have a sensitive stomach or are new to concentrated cannabis
Storage and Shelf Life
Both RSO and FECO are shelf-stable oils, but proper storage extends potency and prevents degradation:
- Store in a cool, dark place — a medicine cabinet or refrigerator is ideal
- Keep the syringe capped — oxygen exposure degrades THC over time
- Avoid heat — do not leave in a car or near a window
- Shelf life: 6–12 months at room temperature, 12–18 months refrigerated
If the oil develops an off smell, changes color dramatically, or becomes grainy, it may be past its prime. Expired RSO/FECO is not dangerous but will be less potent.
Oregon Pricing: What to Expect in 2026
RSO and FECO syringes in Oregon typically range from $15–$40 per gram depending on the brand, cannabinoid ratio, and extraction method. At Green Health Eugene, we carry options across that range, including Siskiyou Sungrown RSO in THC, CBD, and 1:1 ratios. On Tuesdays and Saturdays, all extracts, carts, and concentrates are 15% off — making it the best day to stock up on RSO or FECO.
Local Pairings: The "West Eugene" Wellness Routine
Since RSO and FECO are often used for deep relaxation or pain relief, we recommend low-energy, high-comfort pairings near our Highway 99 dispensary.
The Nature Walk: Once your dose settles in, head to the West Eugene Wetlands (just a few minutes from the shop). The flat, paved paths are perfect for a gentle walk to get some fresh air without strenuous hiking.
The Munchies: You will get hungry. We recommend stopping by Burrito Amigos (also on Hwy 99 N) for a heavy, comfort-food burrito that hits the spot perfectly after a sedative session.
Location: Hwy 99 N, Eugene.
Stop by the shop — Hours, Deals & Directions — 607 Hwy 99 N, Eugene — open daily 9 AM–9 PM with Visa and Mastercard accepted.
Where to Find RSO & FECO in Eugene
At Green Health Eugene, we carry top Oregon brands known for their clean extraction methods, such as Om Extracts, Siskiyou Sungrown, and Farmer's Friend Extracts.Check Our Menu: See what’s in stock on our Live Menu Here.
Ask Questions: Not sure which one is right for your pain level? Ask Jed or any of our staff when you stop by.
(Disclaimer: This article is for educational purposes only. Cannabis is not a substitute for professional medical advice. Do not operate a vehicle or machinery under the influence of this drug. For use only by adults twenty-one years of age and older. Keep out of the reach of children.)
Frequently Asked Questions
What is the difference between RSO and FECO?
The main difference is the extraction solvent. RSO (Rick Simpson Oil) is traditionally made with isopropyl alcohol or naphtha, while FECO (Full Extract Cannabis Oil) is made with food-grade grain alcohol (ethanol) or CO₂. FECO is generally considered safer for oral consumption because ethanol is an FDA-recognized food-safe solvent. Both produce full-spectrum, highly potent cannabis oil.
Does FECO get you stoned?
Yes. FECO is extremely potent — a single gram syringe can contain 600–800 mg of THC, which is the equivalent of 60–80 standard edible doses. Even a grain-of-rice-sized serving (25–50 mg) will produce strong psychoactive effects including body sedation, drowsiness, and appetite stimulation. FECO tends to feel slightly "cleaner" than RSO due to its terpene-preserving extraction, but it is absolutely psychoactive.
Is RSO stronger than other concentrates?
In raw THC percentage, RSO (60–80%) is actually lower than live resin, shatter, or distillate. However, RSO often feels stronger because it is taken orally — the liver converts THC to 11-hydroxy-THC, which crosses the blood-brain barrier more efficiently and lasts 4–8 hours instead of 1–2. Combined with the full-spectrum entourage effect, a rice-grain of RSO typically produces a longer, more sedative experience than smoking higher-THC concentrates.
Is there anything stronger than RSO?
In terms of sustained intensity, RSO and FECO are among the strongest cannabis products available. Distillate tests higher in THC percentage (85–99%) but lacks the full-spectrum plant profile that makes RSO hit so hard. THCA diamonds (95%+) are the most potent single-cannabinoid product, but they are dabbed rather than eaten. For oral, full-body, long-duration effects, RSO and FECO remain the most powerful option.
Does RSO get you more stoned than FECO?
Not necessarily. Both contain similar THC levels (60–80%). RSO may feel heavier due to higher chlorophyll and plant wax content, which some patients describe as a more "body-forward" sedation. FECO's ethanol extraction preserves more terpenes, which can produce a more balanced, nuanced effect. The perceived difference is subtle — strain selection and THC/CBD ratio matter more than the extraction method.
Can I smoke or dab RSO or FECO?
No. You should not smoke or dab RSO or FECO. These oils contain plant waxes, fats, and chlorophyll that are safe to eat but can be harsh and harmful to your lungs when vaporized. They are designed for oral dosing (on food or under the tongue) or topical application only. If you want to dab, choose a concentrate made specifically for inhalation, like live resin, badder, or rosin.
How much RSO or FECO should I take?
Start with a dose the size of a grain of rice — approximately 25–50 mg of THC. If you are new to cannabis concentrates, start with half a grain of rice. Place it on a cracker, piece of chocolate, or under your tongue. Wait at least 90 minutes to 2 hours before taking more. RSO and FECO are extremely potent, and overconsumption can cause anxiety, dizziness, or prolonged sedation.
Where can I buy RSO and FECO in Eugene, Oregon?
Green Health Eugene carries RSO and FECO on our concentrates shelf, including Siskiyou Sungrown RSO in THC, CBD, and 1:1 ratios, plus FECO options from Om Extracts and Farmer's Friend Extracts. We are located at 607 Highway 99 N in Eugene, open daily 9 AM – 9 PM. We accept Visa and Mastercard with no fee — the only Eugene dispensary that does. Extracts are 15% off every Tuesday and Saturday.
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