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Cannabis Safety

Legalizing cannabis for recreational purposes has opened doors to serious debates regarding the safety and efficacy of its use. The two most important components of marijuana- THC and CBD have been the subject of research for several decades. Studies have shown that CBD can counteract the negative effects of THC and optimize its positive therapeutic effects (1). While THC on its own presents a variety of safety concerns, CBD has no known effects of abuse or dependence potential in humans and has been reviewed by the WHO as a safe and well-tolerated compound (2). To date, there have been no reports of any public health-related problems associated with the use of pure CBD. Across several randomized controlled and open-label trials studying the safety and efficacy of CBD, it is generally well-tolerated with a good safety profile. Moreover, the WHO and FDA have recognized CBD as safe and recommended governments to eliminate it from the list of controlled substances. While developing guidelines surrounding recreational cannabis use, safety studies are required to establish scientific evidence-based policymaking.

Some studies have shown that recreational cannabis use in children and adolescents under the age of 18 years results in negative physical and mental health effects (3). Notable concerns surround the access of THC by children and adolescents. Prenatal or exposure through breastmilk has been linked to negative cognitive development, with decreased IQ scores, cognitive function, and attention in children (4). However, numerous human studies have demonstrated the potential of CBD as a treatment for epilepsy-related disorders and behavioral conditions in children, and animal studies have shown potential for the treatment of perinatal brain injury and neuroblastoma (5).

Due to its psychotropic effects, THC has been reported to affect judgment, memory, attention and reaction time with effects lasting up to 5 hours after use suggesting a negative impact on motor vehicle operation (6). Moreover, the method of consumption, quantity consumed, and variety of cannabis can differentially affect the level impairment (7). While a 10 mg oral dose of THC induces psychotropic symptoms, doses of up to 600 mg CBD have failed to produce psychotic symptoms indicating its safety.

Drug-drug interactions must be considered by companies developing therapeutics and wellness products involving THC and CBD, as the informed consumer seeks information about both the product ingredients and their potential impacts on the body. CBD and THC interact with and are metabolized by many of the same enzymes and pathways that process commonly prescribed medications impacting drug concentrations in the body (8).

No deaths have been reported due to cannabis intake, but “greening out” is a term used to describe feeling ill after use, and thus responsible use is critical. Investigating safety profiles is while developing new products and delivery formats is important since extracts of CBD and THC delivered by different routes may react differently than the whole plant would.


Andrew Charrette

Andrew Charrette leads the regulatory affairs division of KGK Science and has an in-depth knowledge of the cannabis regulations in North America and Europe. He has experience in submitting Cannabis Research License applications to Health Canada under the new Cannabis Act, organizing over 50 submissions to Health Canada and has provided consulting for numerous product claims as well as NDIN and GRAS submissions to the US FDA. Andrew received his undergraduate degree in Pharmacology and Physiology from the University of Western Ontario and later obtained a Master’s degree in Neuroscience from the University of Ottawa.


1. Does Cannabidiol Protect Against Adverse Psychological Effects of THC? [Internet]. [cited 2019 Feb 25]. Available from:

2. WHO Report Finds No Public Health Risks Or Abuse Potential For CBD [Internet]. [cited 2019 Feb 25]. Available from:

4. Willford JA, Chandler LS, Goldschmidt L, Day NL. Effects of Prenatal Tobacco, Alcohol and Marijuana Exposure on Processing Speed, Visual-Motor Coordination, and Interhemispheric Transfer. Neurotoxicol Teratol. 2010;32(6):580–8.

3. Adverse Health Effects of Marijuana Use | NEJM [Internet]. [cited 2019 Feb 25]. Available from:

5. Campbell CT, Phillips MS, Manasco K. Cannabinoids in Pediatrics. J Pediatr Pharmacol Ther JPPT. 2017;22(3):176–85.

6. Cannabis use and driving-related performance in young recreational users: a within-subject randomized clinical trial [Internet]. [cited 2019 Feb 25]. Available from:

7. Canada S, Canada S. Drug-impaired driving [Internet]. aem. 2017 [cited 2019 Feb 25]. Available from:

8. Drug-drug interactions as a result of co-administering Δ9-THC and CBD with other psychotropic agents: Expert Opinion on Drug Safety: Vol 17, No 1 [Internet]. [cited 2019 Feb 25]. Available from: