How to Read a Cannabis Product Label
Due to cannabis prohibition, special interest group propaganda, and biased medical research, the majority of people tend to treat cannabis as independent of or segregated from other medicinal herbs. Unfortunately, this has led to widespread misinformation about the plant’s potential adverse effects, as well as it’s potential medical benefits, and has resulted in a general skepticism, paranoia, and mystification of the cannabis plant.
This lack of understanding and fear of cannabis is one of the reasons why public officials tend to create overburdened, over-taxed, and unnecessarily complex regulatory programs, typically favoring large entities that have the resources to win licenses in heavily-regulated, limited markets.
While “legalization” of cannabis has made cannabis products more accessible to many, there is still much confusion about cannabis consumption, efficacy, and labeling. To that end, this post is meant to provide information to those seeking a better understanding of cannabinoids and how information about these compounds is depicted on a cannabis product label.
Understanding the Diversity of Cannabinoids
People are beginning to realize that Tetrahydrocannabinol (THC) concentration is not the sole indicator of quality or efficacy. Consequently, consumers and patients are starting to pay more attention to other cannabinoids like Cannabidiol (CBD), Cannabigerol (CBG), Cannabinol (CBN), Tetrahydrocannabivarin (THCV), and even the acidic forms of CBD and THC (CBDa and THCa).
The significance of the potential synergy between the different cannabinoids cannot be overstated. For example, a recent, randomized placebo-controlled study compared THC, CBD, and combinations of each. The study found that low doses of CBD when combined with THC enhanced the intoxicating effects of THC, while high doses of CBD reduced the intoxicating effects of THC. The THC dose for this study was 8 mg. The low CBD dose was 4 mg (1:2 ratio) and high CBD dose was 400 mg (50:1 ratio). These findings are important to consider when recommending ratios of THC and CBD for both medical and recreational users. They also have implications for cannabis users with lower THC tolerances.
Furthermore, a 2014 study, commissioned by the Netherlands Ministry of Health, assessed the therapeutic satisfaction within a group of about 100 patients using medical cannabis. The study found that cannabis containing higher levels of THC and low levels of CBD is not necessarily more effective than cannabis with a balanced ratio of these cannabinoids, except for stimulation of appetite. Those who used cannabis with cannabinoid concentrations of 6% THC and 7.5% CBD (i.e. “low THC” cannabis) reported significantly less anxiety and dejection (feeling down, sad, depressed) but also reported equivalent levels of therapeutic satisfaction as those patients who reported using “high THC” (19% THC, < 1% CBD) and “medium THC” (12% THC, < 1% CBD) cannabis.
Lastly, if you are using THC consistently and find that you have to increase your dosage more and more to get the same results, you may want to consider incorporating THCa and CBDa (the acidic forms of these cannabinoids) into your cannabis consumption. This can be accomplished by ingesting raw cannabis. Although most research is completed on the decarboxylated and isolated versions of CBD and THC, some research on CBDa and THCa exists. For example, one study found that CBDa activates the 5-HT1A receptor, showing promise as a treatment for nausea and anxiety, while having significantly greater potency at lower doses and affinity for this receptor than CBD.
Understanding Decarboxylation
Decarboxylation (heating) is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Cannabis flowers do not produce THC or CBD; at a molecular genetic level, the cannabis plant converts the precursor cannabinoid Cannabidiolic acid (CBGa) to either THCa or CBDa. Cannabis flowers must be decarboxylated at about 245°F for 45–60 minutes to turn CBDa to CBD or THCa to THC.
Alternatively, you can create a combustion, which occurs at a higher temperature, by lighting the cannabis flowers on fire — smoking is one of the most common ways to consume cannabis. If you wanted to create a simple cannabis tincture or extract, you could decarboxylate before or after soaking the flowers in alcohol. Decarboxylation will remove some of the plant’s terpenes as they are volatile and sensitive to heat.
Nearly all infused products, vape oils, distillates, and other extracts will already contain decarboxylated cannabinoids. Processors will decarboxylate the product to activate the desired effects of delta-9 THC or CBD.
Most of the cannabis plant is non-intoxicating until you decarboxylate, converting THCa to delta-9 THC. Even THC will eventually degrade to the non-intoxicating cannabinoid, CBN, over time with exposure to light, heat, and oxygen.
Because of the loss in molecular weight during decarboxylation (- CO2), there is a difference between the masses of THCa and THC and CBDa and CBD. Consequently, the total percentage of THC or CBD in a gram of cannabis is estimated using the formulas:
Total THC = (% THCa x 0.877) + % THC
Total CBD = (% CBDa x 0.877) + % CBD
[0.877 = Weight after decarb (314.45) / Weight before decarb (358.48)]
Understanding a Certificate of Analysis
All cannabis products start from flower material. Cannabis flowers are the closest you can get to a “full spectrum” product — they contain terpenes, cannabinoids, and other plant compounds that may provide synergistic effects and potentially enhance medicinal value.
Producers are required to send their representative samples to a testing facility, generally an accredited or approved cannabis lab, to determine cannabinoid levels in a given sample. Labs will also test for terpene content, microbiological contaminants, and pesticide residue. The results will be presented in a Certificate of Analysis (COA).
Every lab will have their own version of a COA, some more graphically-rich than others, and may include charts or other visualization tools. At a minimum, all COAs will contain a cannabinoid or potency analysis. Most labs will use high-performance liquid chromatography (HPLC), an analytical technique, to test cannabinoid content and gas chromatography to test terpene content.
The cannabinoid and terpene levels obtained from the COA will then be used to label the cannabis flower appropriately. Other cannabis products such as distillates, isolates, extracts, and infused products will be tested separately as final end products to determine potency.
It’s important to consider that different parts of the plant will have varying cannabinoid potency. A sample sent to the lab to test a specific “batch” may have been taken from the top flower or cola — which would have the highest concentration but is not representative of every bud on that plant. Consequently, due to this practice and a lack of homogenization, it’s possible that advertised THC levels at dispensaries may be inflated.
Understanding the Cannabis Product Label
As we have written before, the unique chemical profiles of distinct cannabis varieties are too complex to be defined by one of two phenotype categories (i.e. indica and sativa). We advocate for a classification system beyond sativa and indica, especially when it comes to labeling products in the best interest of the consumer. It’s important to understand that different ratios of cannabinoids and terpenes are likely to exhibit distinctive properties and, therefore, provide a better understanding of expected effects.
An effective label should provide accurate cannabinoid levels and information about the terpene profile, not just the strain name or whether it’s an indica, sativa, or hybrid. The cannabinoid and terpene levels can then be used to better predict and anticipate potential effects, which could then be described on the label, elaborated upon by trained dispensary staff, or left to be interpreted by the consumer.
Most infused edibles are made with a high-potency THC distillate. Since the majority of terpenes and minor cannabinoids are lost in the distillation process, you are not likely to feel much difference in terms of effect when consuming edibles with the same THC dosage. Indica, sativa, or hybrid labels on infused products are typically, for a lack of a better word, useless.
If you are purchasing raw cannabis flowers, the label may list the percentages of THCa and delta-9 THC separately or the total percentage of THC (recall the decarboxylation formula above). For example, if a label states the product has about 23–26% total THC, the decarboxylation formula has already been applied. At 23–26% total THC, one gram of the product would contain approximately 230–260 mg of THC.
If the label lists THCa and delta-9 THC separately and does not list total THC, apply the decarboxylation formula (% THCa x 0.877 + % THC) to estimate the total THC.
The total milligrams of THC or CBD in one gram of cannabis can be calculated using the formula:
Total mg of THC in one gram = (% Total THC / 100) x 1000 mg
