Oral THC:CBD capsules tripled the rate of complete response for chemotherapy-induced nausea and vomiting in a randomized trial

THC:CBD improved complete response rate (no vomiting, no rescue medication) from 8% to 24% (absolute difference 16%, 95% CI 4-28, p=0.01) during the first chemotherapy cycle. Similar improvements were seen for absence of significant nausea, reduced rescue medication use, and quality of life. Adverse events included sedation (18% vs 7%), dizziness (10% vs 0%), and transient anxiety (4% vs 1%). No serious adverse events attributed to THC:CBD.

Randomized, double-blind, placebo-controlled, two-stage phase II/III trial. 147 evaluable participants (of planned 250) with refractory nausea/vomiting during moderately or highly emetogenic chemotherapy despite guideline-consistent antiemetics. THC 2.5mg + CBD 2.5mg capsules three times daily, days -1 to 5.

Despite modern antiemetics, many cancer patients still experience nausea and vomiting. This trial demonstrates that low-dose THC:CBD can meaningfully improve outcomes when standard treatments are insufficient, using a product that is standardized and tested rather than ad hoc cannabis use.

This is one of the strongest RCT evidence bases for cannabis in cancer care. The standardized dosing (2.5mg THC + 2.5mg CBD, TID) provides a clear protocol that could be implemented in clinical practice, unlike variable cannabis products.

Enrolled 147 of planned 250 participants. Background antiemetic regimens varied. Additional sedation and dizziness may limit use in some patients. Drug availability, legal status, and cultural attitudes may affect implementation. Cost-effectiveness analysis pending.