When most people talk about cannabis and its effects, there are two chemicals that come first in everyone’s minds: delta-9-tetrahydrocannibinol (THC) and cannabidiol (CBD). The two chemicals together account for most of the amount of cannabinoids in cannabis, so it makes sense. Those two are the most prevalent, and the ratio of THC to CBD in a plant is an important predictor of the effects it will have when used.
That said, the concentrations of THC and CBD, and the ratio between the two form only a part of how cannabis affects the body. There are scores of other cannabinoids that, while less prevalent, also have a say in how a particular strain will affect the user. It may be for this reason that synthetic versions of THC produced by the pharmaceutical industry have yet to catch on.
Another major predictor for strain effects is the presence and ratio of different terpenes in the plant. Terpenes are a component of plant resin, and are found in many other plants, from lavender to conifers. They are aromatic, and within the plant kingdom, terpenes are used to discourage herbivores from eating the plant, either by smelling awful to them or by smelling attractive to their predators, or to attract pollinators.
Within cannabis, terpenes are a major component of the smell and taste that make a strain unique. Cannabis plants can create scores of terpenes in varying ratios, depending on any number of factors under a grower’s control. Lighting, nutrient uptake, plant fertilization and irrigation are just a few of the factors that determine the terpene profile of a plant at harvest.
A study published by Dr. Ethan Russo in the British Journal of Pharmacology back in 2011 claims that terpenes are responsible for some of the therapeutic effects in cannabis. He examined the effects of limonene, myrcene, alpha-pinene, linalool, beta-caryophyllene, caryophyllene oxide, nerolidol and phytol in his study. Russo found that terpenes may have synergistic effects with THC, and terpenes may exert considerable control over what effects a strain has.
Although cannabis growers have been optimizing strains to achieve different effects for decades, there is little in the way of standardization. The chemical profile of one grower’s Sour Diesel may be very different from that of another. Terpenes are the key to standardizing strains, so consumers are likely to learn more about them in the search for a consistent effect. Growers who can speak that language stand themselves in good stead.