CBD Levels do Not Reduce High, Says New Study

Liz Filmer
30 Jul 2023

A new study has found that increasing the amount of CBD in cannabis does not reduce the effects of THC. 

Researchers at Kings College London set out to examine the common belief that ingesting cannabis with higher levels of CBD can protect the user from psychotic experiences and memory loss problems. However, the scientists found no evidence to support that. 

Researchers used a set amount of THC and different CBD dosages to explore the oil's effect on cognitive performance or how pleasurable the drug experience was.

The team enlisted 46 healthy volunteers to complete a randomised, double-masked trial over four individual experiments. Each study subject inhaled cannabis vapour containing 10mg of THC and various levels of CBD, 0mg, 10mg, 20mg and 30mg.

The participants must then complete a sequence of assignments, questionnaires and interviews developed to measure the effect on their cognitive capabilities, the harshness of psychotic symptoms, and how enjoyable the drug was.

Overall, the analysis found that increasing the dose of CBD did not alter the effects of THC to any level of significance on the three categories above. 

The study's senior authors said: "Our data suggests that the doses typically present in cannabis do not protect against the adverse consequences of THC".

Such evidence would appear to challenge the commonly held view that cannabis with higher CBD levels provides a buffer against the unfavourable effects of cannabis."

"None of the CBD levels studied protected our volunteers from the acute adverse effects of cannabis"-Lead author Dr Amir Englund. 

The only effect of CBD was that as the concentration of CBD increased, the participants appeared to cough more. Volunteers were asked to listen to music and eat a piece of chocolate each visit. Although cannabis boosted the enjoyment of music and chocolate compared to when the volunteers were sober, CBD had no impact.

The study was funded by research funding from the Medical Research Council. It was recently published in the journal Neuropsychopharmacology.

Liz Filmer