What is the typical daily intake of cannabis CBD (cannabidiol) isolate for an adult patient with a chronic condition, such as cancer, following the RSO (Rick Simpson Oil) protocol?

RSO Protocol and CBD Isolate Dosing

There is no established "RSO protocol" for CBD isolate in evidence-based medicine, and I cannot recommend following this unvalidated approach. The Rick Simpson Oil protocol lacks scientific validation and is not supported by any major medical guideline or regulatory body.

Critical Evidence on CBD Dosing in Cancer Populations

The highest quality evidence from cancer populations shows that CBD doses of 300 mg/day or more carry significant hepatotoxicity risk without proven efficacy for symptom management. 1

Specific Dosing Data from Clinical Trials

• In a phase IIb randomized controlled trial of adults with advanced cancer receiving palliative care, the median patient-selected dose of CBD was 400 mg per day total (titrated from 0.5 mL once daily up to a maximum of 2 mL three times daily of 100 mg/mL CBD oil) 1

• This trial showed no significant benefit on the primary outcome of total symptom distress score, despite patients using this substantial dose 1

• The 2024 ASCO guideline explicitly recommends against using 300 mg or more per day of oral CBD outside clinical trials due to lack of proven efficacy and risk for reversible liver enzyme abnormalities 1

Hepatotoxicity Risk Threshold

No cases of liver injury were reported in adults using total CBD doses below 300 mg/day. 1

• A meta-analysis found a nearly 6-fold increase in liver enzyme elevation and drug-induced liver injury with CBD use 1

• The pooled proportion of elevated liver enzymes was 0.07 (95% CI, 0.05 to 0.12) 1

• Dose-related, reversible transaminase elevations typically occur in the first 2 months after CBD initiation, with 13% reaching three times the upper limit of normal 1

Why the RSO Protocol Lacks Medical Support

The RSO protocol is not mentioned in any major oncology guideline, including the comprehensive 2024 ASCO guideline on cannabis and cannabinoids in adults with cancer. 1

Evidence Limitations

• Evidence remains insufficient to recommend for or against cannabis/cannabinoids for managing cancer treatment-related toxicities or symptoms (including cancer pain) outside specific contexts 1

• Limited high-quality clinical evidence exists on using cannabis/cannabinoids for management of cancer treatment-related toxicities, palliation of cancer symptoms, or improvement of quality of life 1

• Commercial CBD products show inconsistent labeling and vary largely from their label claims, making dosing unpredictable 2

Safer Evidence-Based Alternatives

If considering cannabinoids for cancer-related symptoms, the evidence supports specific FDA-approved products for specific indications only:

For Chemotherapy-Induced Nausea and Vomiting (CINV)

• Adults with cancer experiencing refractory nausea/vomiting despite guideline-concordant antiemetic prophylaxis may augment with dronabinol, nabilone, or quality-controlled oral 1:1 THC:CBD extract 1

• A randomized trial used oral THC 2.5 mg:CBD 2.5 mg three times daily (1-4 self-titrated capsules) from the day before chemotherapy to 5 days after 1

General Dosing Principles

• Start low and go slow: Products should be started at a low dose and slowly increased until the desired effect is achieved, particularly in older adults and those naïve to cannabis 1

• THC total daily dose-equivalent should generally be limited to 30 mg/day or less, preferably in conjunction with CBD, to avoid psychoactive sequelae and development of tolerance 3

• Dose titration should be undertaken slowly over a period of as much as two weeks 3

Critical Safety Warnings

Cannabis use carries well-documented harms that must be weighed against unproven benefits:

• Cannabis use is associated with increased risk for developing depressive disorders and may exacerbate psychiatric disorders in vulnerable individuals 1, 4

• Approximately 10% of adults with chronic cannabis use develop cannabis use disorder 1, 4

• Daily inhaled cannabis use is associated with increased risk of coronary heart disease, myocardial infarction, and stroke 5

• Cannabis users are more than twice as likely to be involved in motor vehicle crashes 4, 6

• High-dose cannabis use can lead to cannabinoid hyperemesis syndrome after long-standing use (>4 times per week for over a year) 1

Clinical Recommendation

I strongly advise against following the RSO protocol with CBD isolate. If you are considering CBD for cancer-related symptoms, consult with your oncology team about evidence-based options, stay below 300 mg/day total CBD dose, monitor liver enzymes if using CBD, and consider FDA-approved cannabinoid medications (dronabinol, nabilone) for specific indications like refractory CINV instead. 1