“This paper aimed to systematically examine the efficacy and adverse event (AE) profile of cannabidiol and medicinal cannabis by analyzing qualitative and meta-analytic data.

According to the results, a statistically meaningful effect of cannabidiol compared with placebo was observed (p < 0.00001). When comparing treatment with cannabidiol or medicinal cannabis, significance was not found for the AE profile (p = 0.74). As AEs for cannabidiol were more common under short-term than under long-term treatment (p < 0.00001), this approach was favorable in the long term.

Furthermore, cannabidiol is more effective than placebo, regardless of the etiology of epileptic syndromes and dosage.

Overall, the AE profile did not differ across treatments with cannabidiol or medicinal cannabis, though it did differ favorably for long-term than for short-term treatment.”

https://www.ncbi.nlm.nih.gov/pubmed/31731110

“CBD treatments were effective compared with placebo, regardless of the dose administered. •The safety analysis is related to tolerable SEs found in studies with both CBD and medicinal CNB. •There was a greater tendency for adverse events in short-term treatment compared with long-term treatment.”

https://www.epilepsybehavior.com/article/S1525-5050(19)30862-5/fulltext