CBD–Terpene Sleep Trial: The Average Effect Was Smaller Than the Best-Responder Result
A CBD–terpene trial found a small average change in wearable-estimated sleep stages, while the largest reported improvements occurred in selected responders. Those responder figures should not be presented as the expected benefit for everyone with insomnia.
A combined formulation and incomplete datasets
The study used 300 mg CBD with eight terpenes, each at 1 mg, in a placebo-controlled crossover design. Treatment periods lasted four weeks, separated by washout. Although 125 participants entered the study, the final complete-data analysis included 56.
The intervention was not pure CBD. Without separate CBD-only and terpene-only arms, the experiment cannot identify which component caused a change or demonstrate a synergistic interaction.
The mean effect was modest
The reported average increase in the combined share of slow-wave and REM sleep was approximately 1.3 percentage points compared with placebo. Total sleep time, resting heart rate and heart-rate variability did not show significant treatment effects.
More substantial estimates appeared in subgroups and selected high responders. A best-responder average is conditional on selection and cannot replace the overall treatment estimate when discussing likely benefit.
The device did not measure laboratory sleep stages directly
Sleep was assessed using a wrist-worn tracking device rather than polysomnography. The authors explicitly questioned the device’s sleep-staging accuracy and called for confirmation in a sleep laboratory.
Loss of complete datasets, the modest overall result and subgroup analyses limit precision and generalizability. The study provides a preliminary signal for a specific combination, not proof of broad insomnia efficacy or an expectation of dozens of additional restorative-sleep minutes for every user.
Related: Interpreting clinical cannabinoid outcomes.
Primary research
Effects of a cannabidiol/terpene formulation on sleep in individuals with insomnia: a double-blind, placebo-controlled, randomized, crossover study. Journal of Clinical Sleep Medicine : JCSM : Official Publication of the American Academy of Sleep Medicine (2025).
