RSO (Rick Simpson Oil) is a highly concentrated, whole-plant cannabis extract developed by Canadian activist Rick Simpson in 2003. Made by extracting the entire cannabis plant with ethanol, it retains a full spectrum of cannabinoids, terpenes, and plant compounds. Traditional RSO is high-THC and dispensary-only. Hemp-derived CBD RSO uses the same method on hemp plants, producing a high-potency, full-spectrum CBD oil that's federally legal in all 50 states.
Whether you've heard about RSO from a cancer patient's story, a chronic pain forum, or a late-night search for the strongest cannabis option available — this guide covers everything honestly: what RSO is, where it came from, what it's used for, how to take it, and what legal high-potency CBD alternatives exist for people who can't access dispensary RSO.
What Does RSO Stand For?
RSO stands for Rick Simpson Oil — named after Rick Simpson, a Canadian engineer and cannabis activist. It is sometimes called FECO (Full Extract Cannabis Oil), which describes the same whole-plant extraction method without the brand association.
The name "RSO" specifically refers to the origin story and extraction method popularized by Simpson, not a proprietary formula. Many cannabis companies produce RSO-style products using similar techniques, and the term has become a general descriptor for high-potency, full-spectrum cannabis extracts in syringe form.
The Origin Story: Who Is Rick Simpson?
Rick Simpson is a Canadian engineer who, in 2003, claimed to have successfully treated his own basal cell skin cancer using a homemade cannabis oil he applied topically. After what he described as a successful self-treatment — the cancer spots on his face and neck appeared to heal — Simpson began producing the oil and sharing it freely with other patients seeking relief from serious conditions.
His story gained widespread attention after the 2008 documentary Run From the Cure, which detailed his experience and his distribution of the oil to thousands of people. Simpson has consistently stated he never sold his oil and never profited from it — a detail that gave his advocacy considerable credibility among patients who distrusted commercial pharmaceutical interests.
Simpson suffered a stroke in 2018 and has since been less publicly active. RSO today is produced commercially by numerous cannabis companies and sold in licensed dispensaries across legal cannabis states, bearing little direct connection to Simpson himself beyond the name and extraction methodology.
No clinical trials have established RSO as a treatment or cure for cancer or any other medical condition. Rick Simpson's personal claims remain anecdotal. Current research into cannabinoids and cancer is preliminary and largely conducted on cell lines and animal models. This post is for informational purposes only. Consult your healthcare provider before using any cannabis product, especially alongside medical treatment.
What Is RSO Made Of?
RSO is made by soaking cannabis plant material — flowers, leaves, and stalks — in a solvent (traditionally naphtha or isopropyl alcohol, though food-grade ethanol is now the standard for quality products) and then evaporating the solvent to leave behind a thick, dark, highly concentrated oil.
Because the entire plant is extracted rather than just the flowers, RSO contains:
- High cannabinoid content — traditional RSO is typically 60–90%+ THC; hemp-derived RSO is 40–80%+ CBD
- Minor cannabinoids — CBG, CBN, CBC, CBDV and others from the whole plant
- Terpenes — aromatic compounds like myrcene, limonene, and beta-caryophyllene that enhance the entourage effect
- Flavonoids and chlorophyll — contributing to the dark color and earthy taste
- Waxes and lipids — plant matter that gives RSO its thick, sticky consistency
This whole-plant profile is what distinguishes RSO from standard CBD oil or THC distillate. The end product is typically dispensed in a plastic oral syringe — which is what people mean when they search for an RSO syringe.
What Is RSO Used For?
RSO is primarily sought by patients managing serious, often treatment-resistant conditions where conventional options have provided incomplete relief:
| Condition | Why Patients Try RSO | Evidence Level |
|---|---|---|
| Chronic pain | High-dose cannabinoids modulate pain receptors; THC + CBD + terpenes for full-spectrum analgesia | Moderate — clinical evidence for cannabis and pain |
| Cancer-related symptoms | Pain, nausea, appetite loss, anxiety — cannabinoids address multiple symptoms simultaneously | Good for symptom relief; no proven anti-tumor effect in humans |
| Sleep disorders | High-cannabinoid RSO promotes sedation; CBN component is particularly sleep-supportive | Moderate — CBD and CBN well-studied for sleep |
| Inflammation | CBD, CBG, and terpenes reduce pro-inflammatory cytokines through multiple pathways | Good — CBD anti-inflammatory mechanisms well-documented |
| Anxiety | Full-spectrum cannabinoids regulate cortisol and serotonin signaling | Good — CBD for anxiety has strong clinical support |
| Cancer treatment | RSO as direct anti-tumor treatment — Simpson's original claim | Preliminary only — animal and cell studies only, no human clinical trials |
RSO vs CBD Oil — What's the Difference?
- 60–90%+ THC content
- Made from marijuana plants
- Psychoactive — will cause intoxication
- Dispensary-only, varies by state
- Strong, earthy taste — hard to palate
- Grain-of-rice starting dose
- Will fail a drug test
- High CBD content, ≤0.3% THC
- Made from hemp plants
- Non-intoxicating
- Legal in all 50 states, no prescription
- Available in natural or flavored options
- Flexible dosing — drops or half-dropper
- Broad spectrum option passes drug tests
The key question most people searching RSO are really asking is: what's the most potent, whole-plant option I can access legally? If you're in a dispensary state, traditional RSO is available. If you're not, or if you need something legal and non-intoxicating, high-potency full-spectrum CBD oil is the closest legal equivalent — same whole-plant extraction philosophy, without the psychoactive THC.
What Is RSO Syrup?
RSO syrup is a water-soluble or lipid-infused version of RSO dissolved into a liquid base — typically simple syrup, MCT oil, or glycerin — to make it easier to dose and consume. The thick, sticky consistency of raw RSO makes it difficult to measure accurately, and syrup formulations solve this by providing a pourable liquid with a known concentration per milliliter.
RSO syrup is popular for patients who want to add RSO to food and beverages or who find the syringe format difficult to use. The cannabinoid content and effects are equivalent to syringe RSO — the difference is purely formulation and ease of use.
What Is RSO in Gummies?
RSO gummies are edibles infused with RSO rather than distillate or isolate. Because RSO is whole-plant extract, RSO gummies contain a full spectrum of cannabinoids and terpenes rather than just isolated THC or CBD. This makes them more therapeutically complex than standard THC gummies. The onset, duration, and effects are similar to other edibles — 45–90 minutes to onset, 4–8 hours duration — but with the added benefit of the entourage effect from the whole-plant extract.
How to Take RSO
Traditional RSO is extremely potent and requires careful, gradual dosing. Rick Simpson's own recommended protocol for high-THC RSO:
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1–2Weeks 1–2 — Micro-dosing Start with a dose the size of half a grain of rice (approximately 25mg) three times daily — morning, afternoon, and before bed. Most new users experience strong sedation. This is normal — tolerance builds quickly.
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3–5Weeks 3–5 — Gradual increase Double your dose every 4 days as tolerance allows. Continue with three doses per day. Sedation side effects typically diminish significantly by week 3–4 as the endocannabinoid system adapts.
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6+Week 6 onward — Maintenance Reach and maintain your target therapeutic dose. For chronic conditions, patients typically settle into 1–2 grams of RSO daily as a maintenance dose — significantly higher than recreational cannabis use.
Traditional RSO is among the most potent cannabis products available. Starting with too large a dose can cause extreme anxiety, paranoia, rapid heart rate, and intense disorientation. This is not dangerous in a medical sense but can be severely uncomfortable and distressing. Always start with a grain-of-rice-sized amount and wait 2+ hours before taking more.
How to take RSO sublingually
Placing RSO under the tongue and holding for 60–90 seconds before swallowing delivers faster onset (15–45 minutes) than swallowing directly. The mucous membranes absorb cannabinoids into the bloodstream, bypassing first-pass liver metabolism and providing more consistent dosing than oral consumption alone.
How to take RSO topically
RSO can be applied directly to skin — this was Simpson's original use case for his skin cancer. Topical application doesn't produce systemic psychoactive effects (for the high-THC version) because cannabinoids don't penetrate into the bloodstream through intact skin at typical topical doses. For localized pain, inflammation, and skin conditions, topical RSO is a common alternative to oral administration.
How Long Does RSO Last?
| Storage Method | Shelf Life | Notes |
|---|---|---|
| Freezer (sealed) | 2+ years | Best long-term storage. Allow to reach room temp before using — cold RSO is too thick to dispense |
| Refrigerator (sealed) | 1–2 years | Standard storage recommendation. Keep away from light |
| Room temperature, dark place | 6–12 months | Acceptable for daily-use portions. Heat accelerates THC to CBN conversion (increases sedation over time) |
| Room temperature, exposed to light | 3–6 months | Light degrades cannabinoids significantly — keep syringe capped and away from windows |
The "how long does RSO last unrefrigerated" question is common — the answer is 6–12 months at room temperature in a dark location, though refrigeration is always preferred for preserving potency.
Where to Get RSO — and the Legal Alternative
Traditional high-THC RSO is available at licensed dispensaries in states where cannabis is legal recreationally or medically. It is not available for purchase online and cannot be shipped across state lines. If you are in a state without legal cannabis access, traditional RSO is not legally obtainable.
Hemp-derived CBD RSO and high-potency full-spectrum CBD oil are available online and ship to all 50 states. They use the same whole-plant extraction philosophy as RSO — complete cannabinoid and terpene profile in a concentrated format — with CBD as the dominant cannabinoid and trace THC (≤ 0.3%) that won't cause intoxication.
Green Planet's 20,000mg Full Spectrum CBD Oil is the closest legal equivalent to hemp RSO — 333mg CBD per mL, complete whole-plant cannabinoid profile (CBD, CBG, CBN, CBC), terpenes, and trace THC (≤ 0.3%). No prescription required. Ships nationwide. Third-party lab verified every batch. View COAs here.
High-Potency CBD Alternatives to RSO — Green Planet Products
For patients seeking the therapeutic benefits of whole-plant, high-potency cannabis in a legal, non-intoxicating format:
- Full Spectrum CBD Oil 20,000mg (60mL) — 333mg CBD per mL. Our most potent tincture. Full cannabinoid and terpene profile. The legal high-potency option for patients who want RSO-level concentration in a hemp format. Taken sublingually for fastest absorption.
- Full Spectrum CBD Tincture 3,000mg / 5,000mg — 50–83mg CBD per mL. For patients building up to higher doses or maintaining at moderate therapeutic levels. Available in multiple flavors.
- CBD + CBG Pain Salve 5,000mg–10,000mg — topical equivalent for localized pain and inflammation. Same whole-plant philosophy as topical RSO application but in a stable, precisely dosed salve format. CBG component provides enhanced CB1 and CB2 receptor binding for superior local pain relief.
- Full CBD Topicals Collection — roll-ons, creams, salves, and massage lotions for targeted pain relief without systemic effects.
What to Look for When Buying CBD RSO or High-Potency CBD
- Whole-plant extraction method: CO2 or food-grade ethanol — these preserve the complete cannabinoid and terpene profile. Avoid products using butane or harsh solvents
- Third-party COA: Certificate of Analysis from an independent ISO-accredited lab confirming CBD potency, THC content (≤ 0.3% for hemp), and absence of pesticides and heavy metals
- Batch-specific testing: COA batch number must match your product — not just any old COA from the brand
- Full spectrum, not isolate: Isolate-based products miss the entourage effect that makes RSO distinct — look for "full spectrum" and a cannabinoid panel showing multiple cannabinoids
- High stated CBD concentration: Look for products with 50mg/mL or higher for therapeutic-level dosing equivalent to RSO
- US-grown hemp: Subject to agricultural regulations — better quality control than imported hemp
If drug testing is a concern, see our complete guide on CBD and drug tests. Full spectrum products contain trace THC — choose broad spectrum if you are regularly tested.
Frequently Asked Questions
RSO stands for Rick Simpson Oil — a highly concentrated, full-spectrum cannabis extract made by extracting the entire cannabis plant with ethanol. Traditional RSO is high-THC (60%+) and dispensary-only. Hemp-derived CBD RSO uses the same whole-plant extraction method on hemp, producing a high-potency, federally legal CBD oil with trace THC (≤ 0.3%).
RSO stands for Rick Simpson Oil, named after Rick Simpson, a Canadian engineer and cannabis activist who popularized the product after claiming to have treated his own skin cancer with homemade cannabis oil in 2003. RSO is also sometimes called FECO — Full Extract Cannabis Oil — which describes the same whole-plant extraction method.
RSO is primarily used by patients managing serious conditions including chronic pain, cancer-related symptoms (pain, nausea, appetite loss), sleep disorders, and severe inflammation. Rick Simpson originally promoted it as a cancer treatment, but no clinical trials have established RSO as a cure or treatment for cancer. Evidence supports cannabis for symptom management — not as a primary cancer treatment.
Traditional RSO is a high-THC (60%+) cannabis extract — dispensary-only, psychoactive, varies by state legality. CBD oil is extracted from hemp with CBD as the dominant cannabinoid and trace THC (≤ 0.3%) — non-intoxicating and federally legal. Hemp-derived CBD RSO bridges the gap: same whole-plant extraction method as RSO but using hemp, producing high-potency full-spectrum CBD that is legal in all 50 states.
RSO is dispensed in a plastic oral syringe for precise dosing — not a needle syringe. The thick, viscous consistency of RSO makes a syringe the most practical delivery format: you can measure exact gram amounts and dispense tiny starting doses (grain of rice = ~25mg). The syringe format has no medical connotation beyond ease of measuring a very concentrated product.
RSO is typically taken sublingually (under the tongue, hold 60–90 seconds) for fastest onset, orally mixed into food, or applied topically to skin. For high-THC RSO, start with a grain-of-rice-sized amount (approximately 25mg) and wait at least 2 hours before taking more. Increase the dose gradually every 4 days as tolerance builds. CBD RSO and high-potency CBD oil follow the same sublingual method with far more flexible dosing due to non-intoxicating CBD.
RSO stored in a cool, dark place lasts 6–12 months at room temperature, 1–2 years refrigerated, and 2+ years frozen. Heat and light degrade cannabinoids. Refrigerated RSO will be very thick — let it reach room temperature before dispensing. Keep the syringe capped and away from light between uses.
RSO is a whole-plant, high-potency cannabis extract developed by Rick Simpson — made by extracting the complete cannabis plant with ethanol, preserving every cannabinoid and terpene. Traditional RSO is high-THC and dispensary-only. Hemp-derived CBD RSO and high-potency full-spectrum CBD oil deliver the same whole-plant philosophy legally in all 50 states — without the intoxication or legal complexity. If you need RSO-level potency without THC, Green Planet's 20,000mg full-spectrum CBD oil is 333mg of CBD per mL with a complete cannabinoid profile verified by third-party lab testing every batch.
