Cannabis refers to a genus of flowering plants originating from Asia.¹ It’s also an umbrella term that includes both marijuana plants and hemp plants, among others. With the flurry of legalization across the United States, CBD and THC derived products have been thrown into the mix in recent years. But the question is, what’s the difference, and what do marijuana and hemp testing labs need to know?

From the perspectives of cultivation, chemistry and regulation, there is a big difference.

The main differences are what you should know.

In a nutshell, it comes down to cannabinoid content—the chemicals that interact with cannabinoid receptors in the brain to regulate how a person feels, moves and reacts.² There are around 66 of these naturally occurring chemicals in cannabis, which includes both psychoactive and non-psychoactive compounds. The buzzwords of the moment are THC and CBD.

• Delta-9 tetrahydrocannabinol (or THC): Many cannabinoids are psychoactive and cross into the brain via the bloodstream. THC is the main intoxicating component in cannabis. In other words, it’s the cannabinoid that causes the high.
• Cannabidiol (known as CBD): Unlike THC, CBD is the non-intoxicating component of the cannabis plant. It’s reported as having little to no adverse side effects, and no public health risks, by the World Health Organization (WHO). It is said to have healing properties without getting you high.
• Industrial Hemp: Hemp is a high-CBD producing variety of cannabis plants, with a low THC concentration. It’s grown as a fiber source, and for its seeds that are extracted from the stem, stalk, leaves and flower of the cannabis plant. It’s doesn’t require the same meticulous growing conditions as marijuana and tends to be tall and skinny with sparse foliage, like bamboo.
• Marijuana: Marijuana is used for recreational and medicinal purposes, with high amounts of THC and moderate amounts of CBD, depending on the strain. Cultivation requires very precise growing conditions to ensure the occurrence of the THC compound, which is found only in female plants. The plants are bushy with large, full foliage.

In conclusion, hemp is not a different species of the cannabis plant. Industrial hemp and marijuana are biologically related. They are different cultivars bred from the same species of plant, Cannabis sativa.

Marijuana cultivars are grown for their high levels of THC, whereas industrial hemp is not. Both marijuana and hemp produce CBD. From a chemical perspective, the molecule is identical regardless of its cannabis source. From a regulatory perspective, however, CBD products derived from hemp and CBD products derived from marijuana are entirely different.

What’s the difference in how hemp, marijuana, CBD and THC are regulated?
It’s a complicated web of federal and state-level activity. The different legislation and regulations inextricably link the compounds. Various state agencies often regulate the hemp and cannabis industries separately, however. Here’s the rundown:

• Industrial hemp: In 2018, the federal Agriculture Improvement Act of 2018 (aka the Farm Bill) reclassified hemp as an agricultural commodity, removing it from the controlled substances list. Although there are statutes at a state level, the bill specifies that harvested crops cultivated by a licensed producer must have less than 0.3% of THC on a dry weight basis. This means hemp does not have any intoxicating effects and any cannabis plant exceeding that limit would be considered marijuana.
• Marijuana: The federal US Drug Enforcement Administration (DEA) classifies cannabis containing more than 0.3% THC as a Schedule I drug with no accepted medical use. This means marijuana is illegal under federal law. But things change at a state level. As it stands today, a total of 33 states have comprehensive, publicly available medical marijuana programs. Adult recreational use of marijuana is now legal for adult use in 11 states and Washington, DC.
• CBD: CBD from the marijuana plant is federally illegal under the Controlled Substances Act due to the DEA classification mentioned above unless purchased from a licensed dispensary in states with comprehensive medical cannabis programs and legal recreational cannabis. Thirteen states further allow the use of “low THC, high cannabidiol (CBD)” products, often required to be derived from hemp. Despite the 2018 Farm Bill’s decriminalization of hemp-derived CBD, it’s still subject to other applicable laws, including the Food, Drug and Cosmetic (FD&C) Act. The FDA treats products containing cannabis or cannabis-derived compounds as it does any other FDA-regulated products. This is true regardless of whether the cannabis or cannabis-derived compounds are classified as hemp under the 2018 Farm Bill.
• THC: The laws surrounding THC vary state-by-state and are changing all the time, but THC products are typically available where there is medical or recreational cannabis reform. Based on individual state regulatory requirements in the US, the potency of commercial marijuana products must be reported as the percentage of THC and printed on the product labels after being certified by a licensed cannabis testing facility.

When it comes to the hemp and marijuana classification, the magic number is 0.3%. When it comes to CBD and THC products, it’s a gray area that has prompted the US FDA to state that a regulatory framework is in the pipeline.

But there are other things to consider.

Hemp is a bioaccumulator and is used to cleanse the soil. This means it absorbs toxins such as pesticides, insecticides, fertilizers and heavy metals. The downside is that CBD extracted from industrial hemp cultivated in non-organic conditions can contain these contaminants. Additionally, CBD products from the black market are not required to undergo any testing for these chemical residues. The consumer has no idea what they are getting when a non-licensed product is purchased.

Medical and recreational cannabis by authorized growers, producers and dispensaries tend to be safer because they are produced according to stricter standards and carefully tested for potency and contamination. The main thing is that you understand the specified detection limits for THC and CBD for the products you are testing within the state or country that you are testing.

What does this mean for cannabis labs testing marijuana and hemp?
Analyzing products from both hemp and marijuana plants is important to assure the efficacy and safety of the products. Mislabeled products are a big problem and a significant concern for consumers. Issues range from inaccurate amounts to completely incorrect ingredients.³

One of the most important tests for cannabis products is the concentration of both CBD and THC. Recent reports have found non-licensed CBD products for sale that do not contain the levels they claimed, or that contain no CBD at all. In addition to testing for potency, safety is paramount. Cannabis products need to be accurately tested for the presence of pesticides, herbicides and plant growth regulators (generically referred to as pesticides), as well as microbials such as mycotoxins.

In legalized markets, many of these chemicals are banned for use in marijuana cultivation as the actual toxicological consequences are unknown and present a real risk to consumers. This demonstrates the clear need for well-regulated legal production, distribution and product testing processes. Cannabis testing laboratories are fundamental to the safety of the entire production pipeline.

High sensitivity, mass accuracy and rigorous detection with linear dynamic range are key when it comes to cannabis product testing. Because of the complexity of cannabis samples, labs should consider employing an instrument system that can handle multiple workflows, such as potency analysis, pesticide testing, mycotoxin analysis and terpenes profiling. The system also needs to isolate and identify as many known and unknown compounds as possible and to detect very low concentrations (in the parts per million or parts per billion range).

LC separation with MS/MS detection is a commonly used technique for cannabis analysis as it meets all these requirements. It offers a fast, accurate and comprehensive analysis of marijuana and hemp-derived cannabis products within required detection limits, where applicable. The SCIEX QTRAP® 6500+ LC-MS/MS System provides exceptional performance in this area. I recommend checking out this technical note that uses the QTRAP 6500+ System to quantify THC in hemp-derived samples.

If you’re interested to learn about instrumentation, here’s a blog I published that gives you a good overview of well-known techniques used to analyze cannabis samples. For those more ready to roll up your sleeves and dive into analytical research in areas of concern, access our Cannabis and Hemp Testing Compendium.

References

1. Pollio, Antonino. “The Name of Cannabis: A Short Guide for Nonbotanists.” Cannabis and Cannabinoid Research, vol. 1, no. 1, 2016, pp. 234–238., doi:10.1089/can.2016.0027.
2. Zou, Shenglong, and Ujendra Kumar. “Cannabinoid Receptors and the Endocannabinoid System: Signaling and Function in the Central Nervous System.” International Journal of Molecular Sciences, vol. 19, no. 3, 2018, p. 833., doi:10.3390/ijms19030833.
3. Bonn-Miller, Marcel O., et al. “Labeling Accuracy of Cannabidiol Extracts Sold Online.” Jama, vol. 318, no. 17, July 2017, p. 1708., doi:10.1001/jama.2017.11909.