Cannabinoids prevented chemo nausea better than placebo but have not been tested against modern treatments
A meta-analysis of 26 RCTs found cannabinoids superior to placebo for CINV prevention but no advantage over active comparators, with nearly all studies predating modern antiemetic regimens.
Quick Facts
What This Study Found
Cannabinoids superior to placebo for overall CINV control (RR 2.65, 95% CI 1.70-4.12); no difference vs active comparators; 23 of 26 studies published before 2000; one recent trial showed THC:CBD promise as adjunctive therapy.
Key Numbers
26 RCTs; 23 before 2000; cannabinoids vs placebo RR 2.65 (1.70-4.12, I2=0%); no difference vs active comparators; nearly half had bias concerns.
How They Did This
Systematic review and meta-analysis of 26 RCTs from inception to March 2024; random effects meta-analysis by endpoint; subgroup analyses by control and design.
Why This Research Matters
Despite decades of interest, almost all evidence predates modern antiemetic protocols, leaving a critical gap for current oncology practice.
The Bigger Picture
The cannabis-for-chemo-nausea narrative is based on decades-old trials. Whether cannabinoids add value to modern triple/quadruple regimens remains unanswered.
What This Study Doesn't Tell Us
23 of 26 studies pre-2000 with dated comparators; heterogeneous designs; insufficient evidence for modern adjunctive use including olanzapine.
Questions This Raises
- ?Does THC:CBD add benefit when olanzapine is included?
- ?Are pre-2000 results still relevant?
- ?What trial designs are needed?
Trust & Context
- Key Stat:
- Cannabinoids were 2.65x more effective than placebo, but 23 of 26 trials predate 2000
- Evidence Grade:
- Clear placebo superiority but nearly all evidence predates current standard of care, severely limiting applicability.
- Study Age:
- Published 2025, search through March 2024
- Original Title:
- Efficacy of cannabinoids for the prophylaxis of chemotherapy-induced nausea and vomiting-a systematic review and meta-analysis.
- Published In:
- Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer, 33(3), 193 (2025)
- Authors:
- Chow, Ronald, Basu, Anna, Kaur, Jagdeep, Hui, David, Im, James, Prsic, Elizabeth, Boldt, Gabriel, Lock, Michael, Eng, Lawson, Ng, Terry L, Zimmermann, Camilla, Scotte, Florian
- Database ID:
- RTHC-06222
Evidence Hierarchy
Combines results from multiple studies to find an overall pattern.
What do these levels mean? →Frequently Asked Questions
Do cannabinoids help with chemo nausea?
They beat placebo clearly (2.65x), but this evidence is almost entirely from trials before modern antiemetic regimens existed.
Should oncologists prescribe cannabinoids for nausea?
Evidence for adding cannabinoids to modern triple or quadruple regimens is insufficient. One recent THC:CBD trial showed promise, but more trials are needed.
Read More on RethinkTHC
- CBD-oil-quality-guide
- anxiety-medication-after-quitting-weed
- cannabis-chemotherapy-nausea
- cannabis-chronic-pain-research
- cannabis-epilepsy-CBD-Epidiolex
- cbd-anxiety-research-evidence
- cbd-for-weed-withdrawal
- cbd-vs-thc-difference
- medical-benefits-of-cannabis
- quitting-weed-before-surgery
- quitting-weed-medication-interactions
- quitting-weed-pregnancy
- quitting-weed-pregnant
- seniors-older-adults-cannabis-risks-medications
- weed-breastfeeding-THC-breast-milk
Cite This Study
https://rethinkthc.com/research/RTHC-06222APA
Chow, Ronald; Basu, Anna; Kaur, Jagdeep; Hui, David; Im, James; Prsic, Elizabeth; Boldt, Gabriel; Lock, Michael; Eng, Lawson; Ng, Terry L; Zimmermann, Camilla; Scotte, Florian. (2025). Efficacy of cannabinoids for the prophylaxis of chemotherapy-induced nausea and vomiting-a systematic review and meta-analysis.. Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer, 33(3), 193. https://doi.org/10.1007/s00520-025-09251-w
MLA
Chow, Ronald, et al. "Efficacy of cannabinoids for the prophylaxis of chemotherapy-induced nausea and vomiting-a systematic review and meta-analysis.." Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer, 2025. https://doi.org/10.1007/s00520-025-09251-w
RethinkTHC
RethinkTHC Research Database. "Efficacy of cannabinoids for the prophylaxis of chemotherapy..." RTHC-06222. Retrieved from https://rethinkthc.com/research/chow-2025-efficacy-of-cannabinoids-for
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.