- What is a Cannabis Potency Test?
- Lack of Standardization
- Methods of Measurement
- Federal Potency Monitoring Program
- Home Testing Kits
From a safety standpoint, it is important to know the concentration of active ingredients such as THC, CBD, and other cannabinoids in cannabis products. Potency is also a major factor for an overwhelming number of consumers when making a purchase in both retail and medical dispensaries across the United States. The way that manufacturers test their cannabis products is by sending a sample from a batch of cannabis products into a lab that specializes in testing cannabis and cannabis products. The main issue with labs is that the lack of federal regulation has failed to set a standard protocol that all labs could follow to obtain similar results. The lack of regulation is a result of cannabis being listed as a schedule I drug on a federal level in the United States. Since states are left to create their own regulations on cannabis testing, the methods for carrying out the cannabis testing may differ.
What is a Cannabis Potency Test?
A cannabis potency test is a lab test that determines the amount of cannabinoids, primarily THC, measured in milligrams per gram which can be converted into a percentage. When a cannabis product is finished and ready to hit the shelves, a small sample of the product batch has to be sent in for testing depending on state regulations. Cannabis companies cannot test these products themselves, instead it is sent to a state-certified lab where technicians utilize instruments that can separate chemical compounds and determine the amount of common cannabinoids in a wide range of cannabis products.
Methods of Measurement
Even though there is no single standardized method of measurement, most labs use high-performance liquid chromatography (HPLC) to measure concentrations of cannabinoids. An HPLC system separates different compounds by using pressure which forces the mixture through a granular material. This method enables chemists to separate cannabinoids, terpenes, and other compounds to detect each of the compound’s concentrations which is why it is one of the most popular methods used in the cannabis industry.Some labs may also use both mass spectrometry and gas chromatography combined to provide a level of accuracy in the identification of compounds. Other chromatography methods that are used for cannabis testing include thin layer chromatography (TLC) and supercritical fluid chromatography (SFC). Not only is the method of measurement important, but the laboratory practices are also important. Cannabis testing facilities should be set to standards similar to pharmaceutical laboratories such as Good Laboratory Practices (GLP), so that testing samples do not get mishandled and are properly measured.
Lack of Standardization
The inconsistencies in cannabis potency among labs in the United States is due to a lack of federal oversight and standardization for assessing cannabis products for potency through regulation. Currently, labs are tasked with setting up their own standard based on their own state’s regulations which can vary. For example, the state of Arizona is only beginning to require cannabis testing as of this year passing bill SB1494 which will enact in November. This means that the Arizona Department of Health Services (ADHS) will certify and regulate labs within the state of Arizona. In Colorado, testing has been implemented in phases over time. First testing for potency, then microbials and pesticides, and then heavy metals as of the beginning of this year. Looking at the big picture, the lack of federal oversight over the cannabis industry as a whole has caused inconsistencies in several different aspects and not just cannabis potency issues. Other inconsistencies in cannabis potency due to the lack of standardization and oversight include testing cannabis at different moisture levels and deceptive practices such as doctoring potency results.
Since labs certified to test cannabis do not adhere to a nationwide standard protocol, the cannabis products tested may not have their potency tracked with accuracy. When labs are tasked with sampling the same batch of cannabis products, most of the results deviate within 20% of each other which 15% is considered the normal variation. This can make a big difference in dosage when using cannabis products. Besides the inconsistencies with THC potency, consumers have to take in consideration the types of cannabis products being used, how it is being consumed, and additional compounds within the cannabis product that can contribute to pain relief or to the feeling of being stoned.
Federal Potency Monitoring Program
The federal potency monitoring program is a quarterly report produced by the National Center for Natural Projects Research at the University of Mississippi, under contract with National Institute on Drug Abuse (NIDA), which monitors the potency of illicit cannabis being distributed across the country that are seized and submitted by the Drug Enforcement Administration (DEA). It is important to note that only samples obtained from the black market are sent in for analysis to this lab and it only serves to provide assessments on the potential health impact of cannabis use and illicit distribution patterns to certain agencies. This particular lab tests for THC in cannabis using gas chromatography which is considered less accurate than HPLC.
Home Testing Kits
Some companies are marketing small testing kits that are affordable for residential growers and consumers alike. They use simple analytical techniques such as thin-layer chromatography (TLC) with specific thin-layers and developing fluid to produce potency results. These tests can be effective to provide insight into the potency of cannabis products when none are provided.