CBG vs. CBD: What's the Difference?

As our understanding of cannabis deepens, so too does our knowledge of cannabinoids. While both THC and CBD have had their moment in the spotlight, other lesser-known cannabinoids, such as CBG, are now starting to capture the interest of scientists and consumers. 

Preclinical studies suggest that CBG may share many beneficial characteristics with CBD. Both CBG and CBD are non-intoxicating cannabinoids that potentially boast antioxidative, neuroprotective, and analgesic properties. When paired together, CBD and CBG may offer powerful anti-inflammatory benefits to treat neuroinflammation.

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But where do the similarities between the two cannabinoids end? A deeper dive reveals that CBG is unique to CBD in many ways. Let's explore how.

What is CBG?

CBG stands for cannabigerol. Cannabigerol is one of more than 120 cannabinoids found in cannabis, and was first isolated in 1964. Research into CBG is still at a preclinical stage, but the studies that are available suggest that it holds considerable therapeutic promise. CBG's analgesic properties may surpass those of THC without the intoxicating hit. There's also evidence to suggest CBG may offer anticancer, antidepressant, and antibacterial qualities.

Cannabigerolic acid (CBGA) is the chemical precursor to all of the well-known cannabinoids. As the cannabis plant matures and grows, enzymes convert CBGA into the three primary cannabinoid acids: tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), and cannabichromenic acid (CBCA). 

Through decarboxylation, CBGA becomes CBG, enabling the cannabinoid to interact with the body's cannabinoid receptors. Research suggests that CBG has a partial affinity for both the CB1 and CB2 receptors. CBG may also stimulate receptors that influence pain, inflammation, and heat sensitivity. 

CBG generally appears in low concentrations in most cannabis plants; however, breeding efforts have resulted in CBG-rich cannabis cultivars. CBG-dominant plants are known as “Type IV” cannabis. Although these cannabigerol-dominant plants aren't yet commonplace in the consumer hemp and cannabis markets, they are actively being cultivated on a relatively large scale. Higher concentrations of CBG will render it easier to extract the cannabinoid for therapeutic use. 

What is CBD?

CBD stands for cannabidiol, a cannabinoid found in high concentrations in type II (THC/CBD dominant) and Type III (CBD-dominant) cannabis and hemp plants. CBD was first isolated from cannabis in the late 1930s and then neglected until the seventies when scientists ignited an interest in its anticonvulsant properties.

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Since then, research has confirmed that purified CBD offers a useful treatment for severe forms of childhood epilepsy. CBD may also boast anti-inflammatory, analgesic, anti-anxiety, anti-nausea, and sedative qualities.

In recent years, CBD has seized the spotlight due to the range of therapeutic benefits it offers. CBD may help mitigate some of THC's less desirable characteristics such as anxiety, paranoia, and impaired cognitive function. Research suggests CBD teamed with THC generally provides more significant therapeutic benefits than either cannabinoid alone, a phenomenon that is called the entourage effect.

CBD acts on the endocannabinoid system through diverse physiological pathways. It has a partial affinity for both the CB1 and CB2 receptors but also binds to several other receptors that form part of the endocannabinoid system. Its mechanisms of action on the body are still not fully understood.

What is the difference between CBG and CBD?

CBG is different from CBD in several critical ways:

• Molecular structure. Cannabigerol and cannabidiol have different molecular structures. Molecular structure refers to the number and arrangement of hydrogen, carbon, and oxygen atoms that constitute a cannabinoid. Dissimilar molecular structures mean that CBD and CBG have different three-dimensional shapes, and therefore bind with the body's cannabinoid receptors in different ways and act on the body distinctively. A cannabinoid's molecular structure also helps determine the bioavailability of the cannabinoid, and its degree of solubility in water.

• Pharmacology. CBD and CBG also activate receptors differently. For example, a 2011 study published in Psychopharmacology compared the effects of CBD and CBG at the 5-HT1A serotonin receptor. CBD appears to exert its anti-nausea effects through its affinity for the 5-HT1A receptor, acting as an agonist (activator). CBG, on the other hand, behaves as an antagonist (blocker) at the 5-HT1A receptor. The findings showed that a pre-treatment with CBG blocked CBD's anti-emetic effects, suggesting that the two cannabinoids bound to the same place, but had opposing actions at this receptor.

• Appetite stimulation. Another critical way in which CBG differs from CBD is in appetite stimulation. Research in rats showed that doses of CBG encouraged the animals to eat more than double their normal food intake. In another study, cannabigerol didn't induce any changes to feeding behavior, but cannabidiol significantly reduced total food intake.

What are the therapeutic effects of CBG?

Although there are no clinical trials that have explored the effects of CBG on humans, a number of preclinical studies offer insights into some of the potential therapeutic effects of CBG. While CBG won't offer you an intoxicating, psychoactive experience, it may provide other unique therapeutic benefits that may help with the following conditions — though more human trials are needed, of course.

• Appetite stimulation. As already discussed, preclinical studies have revealed that CBG can markedly promote appetite in rats. A 2017 study emphasized the therapeutic significance of this finding, pointing out that purified CBG may represent a novel treatment option for cachexia, appetite loss, and wasting in humans. Unlike THC, CBG can help to drive hunger without any undesirable intoxicating effects.

• MRSA bacterial infections. CBG has also demonstrated its clout as a potent antibiotic. Researchers tested the antibacterial potential of 18 different cannabinoids, including cannabigerol, against MRSA. CBG outperformed all of the cannabinoids tested and worked as well as vancomycin, a powerful antibiotic.

• Cancer. CBG boasts anticancer properties due to its ability to inhibit abnormal cell proliferation. Research has provided evidence of its anti-tumorigenic properties by inhibiting the formation of mouse skin melanoma cells. 

With interest in CBG on the rise, expect to see and hear more about this unique cannabinoid both in the research lab and at your local dispensary counter.

Major contributions from Dr. Adie Rae.