Few cannabis topics carry a wider gap between what is claimed for a product and what has actually been demonstrated about it.
1. Why This Article Exists
Most people who search this subject are not hobbyists. They have a diagnosis, or they care for someone who does, and they deserve a straight answer rather than mockery or encouragement.
This is an explainer and an evidence review, not a production guide and not a treatment protocol. It gives no quantities, timings or equipment, and no schedule to follow. Nothing here claims this preparation treats any illness.
2. What the Preparation Actually Is
A whole-plant extract, decarboxylated by its own processing
The material called Rick Simpson Oil, often shortened to RSO, is a whole-plant ethanol extract. Plant material is washed in ethanol, which pulls cannabinoids, terpenes, chlorophyll and waxes into solution; the solids are removed and the solvent driven off with heat, leaving a dark, viscous residue that is never refined further.
Raw cannabis carries its cannabinoids mostly in acid form, principally tetrahydrocannabinolic acid. As Radwan and colleagues note in their 2021 review in Molecules, decarboxylation through age or heat is required to form active delta-9-tetrahydrocannabinol, abbreviated THC. The heating that removes solvent does this, so the oil is orally active in a way raw plant matter is not.
How it differs from other cannabis products
| Product type | Key characteristic |
|---|---|
| Whole-plant ethanol extract | Concentrated, unrefined, decarboxylated, flammable solvent |
| Distillate | Distilled down to a narrow cannabinoid fraction |
| Tincture | Alcohol retained, so dilute by construction |
| Solventless concentrate | Resin separated by ice water, heat or pressure |
3. Where the Story Came From
The originator’s own account
Rick Simpson is a Canadian man who began publishing his own account of making and using cannabis oil in the early 2000s. His website, Phoenix Tears, states that he set the site up in 2004, that his home was raided by the Royal Canadian Mounted Police with a final raid in 2009, and that he left for Europe in 2013.
The founding story, that his oil resolved skin lesions and that he then supplied many others, is his own self-published account. It has never appeared in the peer-reviewed medical literature, and no medical record or independent verification has been published. Treat it as widely repeated and unsourced.
Why it acquired the authority it has
It arrived free, with no product to buy, which disarmed the usual scepticism, and it spread through a documentary and open web pages just as health forums became how people researched illness. Repetition is not evidence.
4. Solvents Are a Hazard Question, Not a Method Question
Ethanol, naphtha and what stays behind
Ethanol dissolves cannabinoids efficiently and is at least a substance humans consume, but it is flammable, with vapours heavier than air that travel across a room to an ignition source.
Older and widely mirrored versions of the instructions named naphtha and other light petroleum distillates. That is a serious problem, not a stylistic preference: naphtha is a variable hydrocarbon mixture sold as fuel and industrial cleaner, with no food-grade specification. The hash oil literature also records petroleum ether and chloroform in use. None belongs near something a sick person swallows.
Evaporation is never complete. Residual solvent stays bound in a thick residue, and a home preparation cannot measure how much. That is why residual solvent testing is mandatory in regulated markets.
Fire and explosion
Driving a flammable solvent off a hot surface generates a large volume of ignitable vapour, and this is where people are physically hurt. Bell and colleagues, in the Journal of Medical Toxicology in 2015, reported twenty-nine patients admitted to a Colorado burn centre with injuries from hash oil production between 2008 and 2014: median burn area ten per cent of body surface, sixty-six per cent needing skin grafts. Those cases involved butane, but the mechanism is the same.
| Hazard | Mechanism | Who is exposed |
|---|---|---|
| Fire and flash explosion | Vapour near heat or a spark | The maker and the building |
| Residual solvent | Incomplete evaporation from a thick residue | The patient, repeatedly |
| Petroleum solvent toxicity | Non-food-grade hydrocarbons | The patient |
| Concentrated contaminants | Extraction pulls in what was on the plant | The patient |
| Unknown potency | High concentration, no analysis, no label | The patient and household |
5. Concentration and Accidental Over-Consumption
The National Institute on Drug Abuse reports that tetrahydrocannabinol potency in seized illicit cannabis roughly quadrupled between 1995 and 2022, from 3.96 to 16.14 per cent, and that dispensary flower and concentrates can exceed forty per cent, with hash oil documented as high as ninety per cent. An amount small enough to vanish on a fingertip can carry more tetrahydrocannabinol than a large quantity of flower.
Add an oral route whose delayed onset tempts people to take more before the first amount works, and accidental over-consumption becomes the harm most often reported: severe anxiety, panic, disorientation, vomiting, racing heartbeat and, at the extreme, transient psychotic symptoms. The National Center for Complementary and Integrative Health also lists unintentional poisoning of children among documented cannabis harms.
6. The Regimen That Circulates Online
The regimen escalates: it starts at an amount described as barely perceptible, increases at fixed intervals, and builds over two to three months toward a daily total far beyond what a regular consumer would take. Sedation is presented as proof it is working rather than as a dose-limiting side effect. This article does not reproduce the figures.
There has been no randomised controlled trial of this preparation and no controlled case series, and no pharmacokinetic characterisation of it as a product. The schedule comes from one person’s account, not from dose-finding work.
7. What the Evidence Actually Shows
Laboratory and animal work
The National Cancer Institute’s professional summary on cannabis in cancer care records that cannabinoids may produce antitumour effects in laboratory models, including cell death and inhibition of cell growth, and that mouse and rat studies showed reduced liver tumour development with tetrahydrocannabinol. It also notes a finding rarely quoted in testimonials: in immunocompetent animals, tetrahydrocannabinol appeared to suppress antitumour immunity and enhance tumour growth.
Why culture-dish concentrations do not translate
A compound applied to cells at a chosen concentration is in a completely different situation from one swallowed: it must survive the gut, pass the liver, and reach the target tissue at a comparable concentration. Most compounds that kill cancer cells in vitro fail somewhere in that chain. Cancer Research UK states it directly: the research so far has been laboratory research with mixed results, so we do not know whether cannabinoids can treat cancer in people.
The human data
It is thin, and it concerns pharmaceutical-grade cannabinoids rather than this preparation. Guzmán and colleagues published a safety pilot in the British Journal of Cancer in 2006: nine patients with recurrent glioblastoma received delta-9-tetrahydrocannabinol, median survival from relapse surgery twenty-four weeks. Twelves and colleagues published a phase 1b randomised placebo-controlled trial in the same journal in 2021, adding a nabiximols spray to temozolomide in recurrent glioblastoma; with twelve patients on nabiximols and nine on placebo, one-year survival was 83 against 44 per cent, and the authors called for an adequately powered trial. That study was far too small to conclude anything, and used a product that is not this oil. The National Cancer Institute states that the United States Food and Drug Administration has not approved cannabis or cannabinoids as a cancer treatment.
Symptoms and tumours are different questions
Whether a cannabinoid helps someone eat, sleep or feel less sick is a question about symptoms. Whether it shrinks a tumour or extends life is a question about disease. The first has supporting evidence. The second does not.
| Question | Evidence status |
|---|---|
| Cannabinoids affect cancer cells in the laboratory | Supported, alongside unfavourable animal findings |
| This extract shrinks tumours in people | No randomised trial, no controlled case series |
| Pharmaceutical cannabinoids extend cancer survival | Not established; small early-phase signals |
| Cannabinoids help chemotherapy-induced nausea | Supported; approved medicines exist |
| Cannabinoids reliably relieve chronic pain | Modest at best; small effect sizes |
| This preparation is safe alongside cancer treatment | Not established; interaction concerns |
8. Why Personal Testimony Misleads Here
Four filters shape what you read. Selection: someone who improves posts, someone who dies does not, so what survives online looks like a success rate and is not one. Concurrent conventional treatment: many testimonials describe people also receiving surgery, chemotherapy or radiotherapy, and the National Cancer Institute notes a study of 13,180 cancer patients in which 33 per cent used cannabis after diagnosis. Spontaneous remission: uncommon, but across millions of patients it happens, and whoever it happens to credits whatever they were taking. Absent follow-up: testimonials are written at the moment of hope; cancer outcomes are measured in years.
9. Documented Harms
Delaying or refusing conventional treatment
This is the most serious documented harm, and it has real numbers behind it. Johnson, Park, Gross and Yu published two analyses in 2018. In the Journal of the National Cancer Institute they matched 281 patients with curable cancers who used alternative medicine instead of conventional treatment against 560 conventionally treated patients: the hazard ratio for death was 2.50 overall, 5.68 for breast cancer, 2.17 for lung cancer and 4.57 for colorectal cancer. In JAMA Oncology the same group found five-year survival of 82.2 against 86.6 per cent among complementary medicine users, and concluded the excess mortality was mediated by their much higher refusal of conventional treatment.
Interactions with cancer treatment
Antoniou, Bodkin and Ho reviewed cannabinoid drug interactions in the Canadian Medical Association Journal in 2020. Tetrahydrocannabinol and cannabidiol are metabolised by cytochrome P450 3A4, tetrahydrocannabinol also by 2C9, and cannabidiol inhibits 2C19 and 3A4/5. Documented consequences include raised international normalised ratio and bleeding risk with warfarin, and threefold rises in a clobazam metabolite and in tacrolimus levels.
Bar-Sela and colleagues reported in Cancers in 2020 a prospective study of 102 patients with advanced cancer on immunotherapy: the 34 who also used cannabis had shorter median time to progression, 3.4 against 13.1 months, and shorter median survival, 6.4 against 28.5 months. It is observational and confounded, but it is a reason to tell the treating team.
Contamination, concentrated
Extraction concentrates whatever was on the plant. Park and colleagues, in Frontiers in Pharmacology in 2020, catalogued it: 84 per cent of analysed cannabis samples contained pesticide residues, with up to 24 agents; Aspergillus and Fusarium produce mycotoxins, and the review describes a lung cancer patient who died of invasive pulmonary aspergillosis nineteen days after diagnosis following cannabis use during chemotherapy; cannabis hyperaccumulates cadmium, lead and mercury from soil; and 69 per cent of 84 cannabidiol products were mislabelled.
Ruchlemer and colleagues made the point in Supportive Care in Cancer in 2015: microorganisms carried on cannabis leaves and flowers risk opportunistic lung infection, primarily from inhaled moulds, in patients whose immunity is compromised.
10. Laboratory Testing and the Certificate of Analysis
A certificate of analysis is what a licensed laboratory issues for a specific batch. California’s Department of Cannabis Control requires testing across eight categories, with a pass or fail for each substance. Six matter most for a concentrate.
| Test category | Why it matters for a concentrate |
|---|---|
| Cannabinoids and terpenes | Concentration drives accidental overexposure |
| Residual solvents | The core hazard of a solvent extract, invisible without testing |
| Pesticides | Extraction concentrates residues rather than removing them |
| Heavy metals | Taken up from soil, then concentrated by extraction |
| Microbial impurities | Directly dangerous to immunocompromised patients |
| Mycotoxins | Heat-stable, not removed by evaporation |
An unlabelled oil is uniquely risky for an immunocompromised patient: none of these failure modes can be detected by looking, smelling or tasting.
11. The Legal Position in Thailand
Cannabis flower was removed from Thailand’s narcotics list in June 2022, but extracts containing more than 0.2 per cent tetrahydrocannabinol remained Category 5 narcotics. A concentrated whole-plant extract is far above that threshold.
That flower is now controlled by name. The Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis), B.E. 2568 — signed 23 June 2025, published in the Royal Gazette on 25 June 2025 (Vol. 142, Special Part 229 Ngor) and in force the following day — makes the inflorescence a controlled herb: sale for medical purposes only, against a prescription written by one of the recognised practitioner groups and covering no more than thirty days, with commercial advertising and online sale prohibited. Extracts are governed separately: the Ministerial Regulation on Cannabis or Hemp Extracts B.E. 2569, in force from 26 April 2026, restricts licences for extracts above 0.2 per cent THC to Thai juridical persons that are not “foreign” under the Foreign Business Act, to state agencies, and to the Thai Red Cross. Nothing in either instrument makes a home-made or informally supplied concentrate lawful. Policy has moved repeatedly since 2022, so confirm the current position before acting on it.
12. What a Patient or Carer Can Actually Do
Tell the treating team. Oncologists are not trying to police what patients take; they are trying not to be blindsided by an interaction, an infection or a liver result they cannot explain.
Ask about interactions, naming any cannabinoid product, and whether it affects anticoagulation, immunotherapy or any drug using the enzymes above. Ask a hospital pharmacist if the oncologist is uncertain. A prescribed product has a known composition, a tested batch and an accountable professional; an unlabelled jar has none of that.
Keep the two questions separate. Whether a cannabinoid might help with nausea, appetite, sleep or pain is a legitimate conversation with a treating team. Whether an unregulated concentrate should replace or delay cancer treatment is a different question, and the survival data answers it. The National Center for Complementary and Integrative Health puts it simply: do not use cannabis or cannabinoids to postpone seeing a health care provider about a medical problem.
If you are living with a serious illness, or caring for someone who is, and you have looked into this preparation, tell us below what you were told, what you were promised, and what actually happened. Honest accounts, including the ones that did not go well, are the most useful thing this community can give someone searching at two in the morning. But a forum thread is not a second opinion, and nothing here replaces the doctors, nurses and pharmacists who know your case. Tell them what you are taking.
This article is part of the Asiannabis Community educational series on extraction and post-harvest processing. It is general information, not medical advice. Content is for educational purposes within jurisdictions where cannabis processing is legally permitted.