Do medical cannabis growers attempt to produce cannabis with different cannabinoid concentrations than recreational growers?, Sharon R. Sznitman et al., 2019,

Do medical cannabis growers attempt to produce cannabis with different cannabinoid concentrations than recreational growers?

Sharon R. Sznitman, Monica J. Barratt, Tom Decorte, Pekka Hakkarainen, Simon Lenton, Gary Potter, Bernd Werse and Chris Wilkins

Drugs and Alcohol Today, 2019, 19, (4), 251-256,

Doi : 10.1108/DAT-06-2019-0021



Purpose – It is conceivable that cannabis cultivators who grow for medical purposes aim to improve the therapeutic index of their cannabis by attempting to produce particular concentrations of CBD and/or THC. The purpose of this paper is to examine whether small-scalemedical cannabis growers differ fromthose growing for recreational reasons in terms of self-assessed concentrations of THC and CBD in the cannabis they grow.

Design/methodology/approach – Data collection was conducted online from a convenience sample of 268 cannabis growers visiting a popular Israeli cannabis internet forum. χ2 and Kruskal–Wallis H were used to test bivariate associations between medical and recreational cannabis cultivators in terms of self-assessed cannabinoid concentrations.

Findings – In total, 40 percent of cannabis growers reported that they grow for medical purposes. Medical cannabis growers were more likely to report that they thought they knew the cannabinoid concentrations of the cannabis they grew and they reported higher self-assessed concentrations of THC, but not CBD.

Originality/value – Compared to recreational growers, medical cannabis growers are more likely to strive to be informed in terms of the content of their cannabis. Medical growers may also be attempting to grow more potent THC but not CBD cannabis.

Keywords : Israel, Cannabis cultivation, Medical cannabis, CBD, Potency, THC


Cannabis is the most widely used controlled drug in the world. While most commonly used for recreational purposes (e.g. to get high, socialise), cannabis is increasingly being recognized and used as a remedy for various medical symptoms and conditions (The National Academies of Sciences, Engineering, and Medicine, 2017). Cannabis contains numerous cannabinoids, but Δ9-tetrahydro-cannabinol (THC) and cannabidiol (CBD) are typically the most concentrated components (Russo, 2011). THC is usually the most prevalent psychoactive constituent, producing the “high” associated with cannabis use. THC can also induce anxiety, psychotic-like experiences and cognitive impairment (Colizzi and Bhattacharyya, 2017). At the same time, research shows that THC possesses immunosuppressive and neuroprotective properties ( Jamontt et al., 2010). Furthermore, research suggests that CBD has neuroprotective, anti-inflammatory and anti-oxidative properties (Campbell and Gowran, 2007; Cheng et al., 2014) and that it may attenuate the psychotic-like effects of THC (Russo, 2011).

Small-scale (non-commercial) domestic cannabis cultivation has grown rapidly in Europe and North America over recent years (Chadillon-Farinacci et al., 2015; Potter et al., 2015; Davenport and Caulkins, 2016). Yet, small-scale growing is likely to supply only a modest share of the overall cannabis market, especially in jurisdictions that have legalised cannabis which, in turn, is associated with increases in large-scale cannabis cultivation and “professionalisation” of the cannabis market (Davenport and Caulkins, 2016). Furthermore, research has found that people who report that they grow cannabis to provide themselves or others with cannabis for medical purposes (henceforth “medical cannabis cultivators”) represent a substantial proportion of small-scale cannabis growers (Hakkarainen et al., 2015, 2017).

It is possible that “medical cannabis cultivators” differ from “recreational cannabis cultivators” in terms of the self-assessed THC and CBD concentrations in the cannabis they grow because of a desire to achieve a selective breed of cannabis that is thought to improve the therapeutic index. Because THC is the main psychoactive ingredient and because medical users may not seek the psychoactive effects of cannabis, medical cultivators may attempt to achieve lower levels of THC than recreational growers. Indeed, there is some evidence that medical cannabis patients prefer lower THC cannabis because it treats their symptoms without the accompanying psychoactive highs (Harris et al., 2000). Nevertheless, THC is known to have therapeutic effects and thus there is also reason to expect that medical growers may not attempt to produce lower THC concentrated cannabis than recreational growers. Since CBD is known to have therapeutic effects, but no psychoactive effects, medical cannabis cultivators may be more likely than recreational cannabis cultivators to attempt growing high CBD cannabis. It is also possible that the differences between growers lie in the CBD:THC ratio that due to the potential therapeutic benefits of both THC and CBD medical cannabis growers may be more likely to attempt a relatively balanced CBD:THC ratio.

The aim of this study is to expand the knowledge on medical cannabis cultivators by examining whether small-scale medical cannabis growers differ from those growing for recreational reasons in terms of self assessed concentrations of THC and CBD in the cannabis they grow. The sample consists of small-scale cannabis growers in Israel. Israel is an interesting case study for the current project as it is the home of an established medical cannabis programme. Indeed, the Israeli Ministry of Health has been running a cannabis program since the 1990s and there are (as of 2017) approximately 28,000 licensed medical cannabis patients in Israel (Zarhin et al., 2018; Tandowski et al., 2019). There are eight private growers who legally supply these patients with medical cannabis. Israeli cannabis policies do not allow for home growing for medical or recreational purposes. Nevertheless, unlicensedmedical cannabis use has been reported (Sznitman, 2017; Tandowski et al., 2019) and the current study focuses on a sample of cannabis cultivators who grow cannabis illegally.