Terpenes: what your nose knows

What’s the first thing we usually do when presented with a strain of Cannabis after giving it a quick glance? We smell it. That sniff test is a critical part of the decision-making process, and for good reason. The organic molecules that account for the differing aromatic profiles in Cannabis and many other plants and herbs are called terpenes and they play important roles — beyond creating pleasurable aromas — which are now being investigated.


The word terpene comes from turpentine, an aromatic substance found in many species of pine trees. Technically, a terpene is composed of various structurally linked configurations of 2-Methylbutane, often known as isoprene. Terpenes are sometimes referred to in scientific literature as isoprenoids. Terpenes are classified by the number of these isoprene units linked together, hemiterpenes have one, monoterpenes have two, sesquiterpenes have three, and so forth. There are about 30,000 terpenes known so far. It is important to note that all of the 70 or so cannabinoids found in Cannabis are derived from monoterpenes. Terpenes usually have distinctive odors associated with them, and mixing and matching them up in varying ratios and compositions gives rise to the aromatic symphonies found in many plants and fruits. It is this blending of terpenes that allows for the manufacturing of different perfumes and fragrances used in many products.

The power of aroma

Smells can have a powerful affect on people and other organisms. Many people have the experience of encountering a smell that triggers a strong and vivid memory. Structurally, terpenes are able to bind to specific receptors, just as some cannabinoids do, and just as the binding of cannabinoids to certain receptors have a profound effect, so do some terpenes. Terpenes are used indirectly by some plants as warning signals to communicate the presence of pathogens or insects, and directly as deterrents to those same attackers. Some insects use terpenes from plants to synthesize pheromones that they use for their own purposes. The practice of aromatherapy is a well-documented means of using terpenes for varying effects. Some terpenes are known to have distinct physiological effects, one example is the monoterpene valtrate that occurs in the herb valerian, Valeriana officinalis, known for its sedative and tranquilizing effect.

Terpenes in Cannabis

Besides the obvious terpenoids that compose the cannabinoids like THC, CBD, CBN, CBC, CBG, and many more that are found in varying amounts in Cannabis, there are hundreds of terpenes found in Cannabis. One researcher who has performed a great deal of work in this field is Dr. Jeffrey Raber. Dr. Raber and the researchers at The Werc Shop laboratory in California have identified many terpenes in Cannabis, and are investigating the use of terpene profiles as a tool for strain identification and product development. Sativa Labs in Colorado is compiling terpene profiles with the goal of determining terpene inheritance patterns in Cannabis strains, especially in genetically isolated strains. Some of the terpenes found in Cannabis are pinene, camphene, cineol, myrcene, limonene, terpinene, caryophyllene, linalool, and selinene are but just a few of the terpenes identified in Cannabis so far.


Cannabis is an extraordinarily prolific natural chemical factory that produces hundreds of simple and complex organic compounds, many of which are being proven to have known health benefits. The interaction between the various terpenes and terpenoids, alkaloids, and other compounds of pharmaceutical interest in Cannabis is a field that has just begun to be seriously investigated. When picking strains at a dispensary, it is sometimes easy to find a few that share nearly identical cannabinoid profiles; say 15 percent Δ-9 THC, 0.05 percent CBD, and 0.1 percent CBN. One may be labeled as an indica-dominant, and the other may be called sativa-dominant. Consuming the two at separate times usually reveals a distinct difference in the subjective effects. One influencing factor must be the terpenes, as preliminary work has shown that some terpenes moderate or amplify the effects of cannabinoids. There is a lot of anecdotal evidence that ingesting mango prior to cannabis will hasten and amplify the high. Mangoes produce a lot of the terpene myrcene, which features prominently in some fast- and hard-hitting Cannabis strains.

Some other strains have an opposite ‘creeper’ effect. This writer recalls that in the late 70s there was a wide array of Cannabis being imported from the tropics, and one strain of Colombian was locally known as Creeper; this one would have no effect for about one-half hour and then wham, you were suddenly and extremely high. Some strains have a wave-effect of coming and going for a long period of time, some make everything funny, induce the munchies, make you lazy, or make you incredibly inspired to get things done. Terpene interactions surely play a role in these different effects found in various strains.


That there are complex interactions between the active components in Cannabis seems clear, the exact nature of those interactions is much less well-known. There are lots of research and development opportunities opening up, especially in states where the legal climate regarding Cannabis has relaxed considerable in recent years. Determining the synergistic interactions between cannabinoids, terpenes, and other compounds produced in Cannabis will be a fascinating endeavor for researchers. Novel medicines can be formulated by isolating particular cannabinoids and terpenes and combining them in different ways. Perhaps research will allow a better understanding of why one strain makes everything funny, and another might generate deep insights and inspirations; and how one strain is excellent for quelling seizures, another is best for easing the effects of PTSD, and yet another is fantastic for easing chronic pain problems. Another interesting area to pursue from a research perspective is how the aroma profiles change with differing cure techniques and times.

Trust your nose

Perhaps one subconscious aspect of performing the sniff test of different strains is that our nervous system or other bodily responses react subtly to the terpenes in the differing strains. If true, that may explain why we choose a strain different from what we originally intended to acquire, based on our response to how the strain smelled. Perhaps our bodies are wiser than we give credit to sometimes, and we react to a particular aroma blend because it signals that what we need is found in one strain more than another. Or it may be that we simply prefer one type of aroma more than others. We may not know why, but quite possibly our noses know.
Paul Lembeck owns Sativa Labs, an analytical laboratory conducting Cannabis research Sativa Labs; and Global Heritage Seeds, a Colorado licensed seed farmer labeler, currently providing seeds for legal adult cultivation in Colorado.

— Paul Lembeck