2025 | Germany | Phase 3 randomized trial
Karst M et al. Nature Medicine. 2025;31:4189-4196.
Methods: A multicenter trial enrolled 820 adults to compare the standardized full-spectrum extract VER-01 with placebo during a 12-week blinded phase. Subsequent phases included open-label treatment and a randomized withdrawal comparison.
Findings: The extract reduced pain by an average of 0.6 points more than placebo on a 0 to 10 scale. Adverse events occurred in 83.3% of extract recipients and 67.3% of placebo recipients. The withdrawal phase did not meet its primary endpoint.
Limitations: The average placebo-adjusted benefit was modest and specific to this formulation. Open-label improvements do not provide the same protection against bias as a blinded comparison. Results cannot be assumed for retail cannabis products.