Terpenes: what they are, the main cannabis terpenes and their effects
By the Golden High teamUpdated 9 November 202610 min read
Aroma & chemistry
Terpenes are the aromatic molecules plants make: in cannabis, they're what give each flower its smell of lemon, pine, pepper or forest floor. More than 200 have been described in the plant, produced in the same resin glands as the cannabinoids. Here are the main ones, what we really know about their effects, where the entourage effect debate stands, and what separates a natural terpene from an added one.
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What are terpenes? The scent of plants.
Terpenes aren't unique to cannabis. They form the largest family of chemical compounds in the plant kingdom: between 15,000 and 20,000 have been fully characterised. Lemon, lavender, pine, hops and black pepper all owe their scent to them. Plants use them to attract helpful insects, repel others or protect themselves.
In cannabis, they're made in the glandular trichomes, the tiny shiny glands covering the flowers, from the same precursor as the cannabinoids. Researcher Ethan Russo puts it this way in his 2011 review: it's the terpenoids, not the cannabinoids, that are responsible for the smell of cannabis.
You'll come across two words: terpene means the basic molecule, made of carbon and hydrogen; terpenoid means its modified version, often containing oxygen, like linalool. In practice, and in this article, we say terpenes for both.
- What they are: volatile aromatic molecules, found in almost every plant.
- Where in cannabis: in the trichome resin, alongside the cannabinoids.
- How many: over 200 described, but less than 1% of the weight in most analyses.
- What they aren't: cannabinoids. None of them produces the effect of THC.
Cannabis terpenes
The five terpenes you'll run into everywhere.
Dozens of terpenes can coexist in a single flower, but a few dominate most profiles. The aromas below are common descriptions; the last column sums up what's reported about them, with no guarantee: most of the data comes from animal studies or essential oils.
| Terpene | Aroma | Also found in | What's reported |
|---|---|---|---|
| Myrcene | Earthy, musky, herbal | Hops | Often the most abundant; "couch-lock" reputation, put forward as a hypothesis |
| Limonene | Citrus, zest | Lemon and other citrus fruits | "Uplifting" reputation, mostly drawn from animal studies |
| Alpha-pinene | Pine, resin | Conifers | The most widespread terpene in nature |
| Linalool | Floral, lavender | Lavender | Calming reputation, based on research into lavender |
| Beta-caryophyllene | Peppery, spicy, woody | Black pepper | Binds to the CB2 receptor, with no psychoactive effect |
Myrcene deserves a special mention: a 2020 review describes it as the most common terpene in most cannabis strains. Its earthy, slightly fruity scent is what many people think of as "the smell of weed". Beta-caryophyllene is the other oddity: it's the only terpene shown to bind directly to a receptor of the endocannabinoid system, CB2. We explain it in our article on CB1 and CB2 receptors.
Monoterpenes
Limonene, myrcene, pinene: small and highly volatile. They dominate the scent of a fresh flower, but are the first to evaporate during drying and storage.
Sesquiterpenes
Caryophyllene, humulene: heavier and more stable. Their relative share grows as the flower ages, hence spicier, woodier aromas over time.
What the sources say
Well-described terpenes, less clear effects.
The chemistry of terpenes is solid. Their role in the effects of cannabis much less so. Here's the reference research, from most favourable to most critical. References at the bottom of the page.
British Journal of Pharmacology · 2011
In his review "Taming THC", Ethan Russo counts more than 200 terpenoids in cannabis, rarely more than 1% of the plant but up to 10% of trichome content. He puts forward the hypothesis of a synergy with cannabinoids, while stating that it still needs to be proven.
PNAS · 2008
A Swiss and German team shows that beta-caryophyllene, found in many spices, binds selectively to the CB2 receptor and activates it. The authors describe it as a non-psychoactive dietary cannabinoid. The results come from cells and mice.
Frontiers in Pharmacology · 2020
Five terpenes (myrcene, alpha- and beta-pinene, beta-caryophyllene, limonene) are tested on CB1 and CB2 receptors, alone and with THC or CBD. Apart from a weak interaction between caryophyllene and CB2, no direct effect is observed.
Medical Cannabis and Cannabinoids · 2020
An Israeli review counts 110 terpenes and 121 terpenoids published for the plant, and notes that terpenes break down during prolonged storage in poor conditions.
PLOS One · 2022
Nearly 90,000 commercial samples analysed in six US states: the "indica", "sativa" or "hybrid" labels don't match distinct terpene profiles.
The takeaway: terpenes explain a flower's smell and taste very well. When it comes to effects, we're still in the realm of hypotheses and reputations.
Reported effects
Your nose can't predict what you'll feel.
You read everywhere that a lemony smell "boosts" and an earthy one "chills you out". The previous version of this article said so too. It's a reputation, not a rule: no human study has shown you can predict a flower's effect from its smell. What users feel depends first on the cannabinoids, the dose, how they use and the person.
- "Lemon = energy". Limonene has an uplifting reputation, but the data mostly comes from animals and essential oils.
- "Myrcene = sofa". The idea that it drives "couch-lock" is a hypothesis from Russo, never shown in humans.
- "Indica relaxes, sativa wakes you up". The 2022 analyses show these labels say nothing about the terpene profile.
- "More terpenes, more effect". A high terpene level mostly means more aroma.
That doesn't mean all flowers are the same. The terpene profile really does change the taste, the smell and the pleasure of a session, and that's a perfectly good reason to prefer one flower over another. We develop this idea in why two flowers can feel completely different, and look at the categories in sativa, indica, hybrid: do they still mean anything.
The entourage effect
An appealing idea, not yet proven.
The entourage effect is the idea that the plant's compounds work better together than apart. The term comes from a 1998 paper by Raphael Mechoulam's team, which was originally about molecules made by our own bodies, not terpenes. Ethan Russo extended it in 2011 to the plant's cannabinoids and terpenes.
1998
Ben-Shabat, Mechoulam and colleagues describe an "entourage": inactive molecules in the body boost the activity of an endocannabinoid.
2011
Russo suggests that cannabis terpenes modulate the effects of THC. He writes himself that this synergy still needs to be proven.
2020
A New Zealand study finds no direct effect of the main terpenes on CB1 and CB2 receptors. If the entourage effect exists, it works through other pathways.
So the debate is open, and it's only honest to present it that way. We've covered it in detail in a dedicated article: the entourage effect, when terpenes and cannabinoids team up.
Natural or added
Added terpenes: what the label says, and what it doesn't.
In a flower, terpenes are natural: they come from the plant itself. In vapes, distillates and some concentrates, it's different. Extraction and distillation strip out part of the terpenes, and manufacturers add some back to restore flavour. These added terpenes can be extracted from cannabis, from other plants (citrus, conifers and so on) or made synthetically. A "natural terpenes" label doesn't tell you which.
One thing to watch is heat. In 2017, chemists at Portland State University simulated a "dab" with myrcene, limonene and linalool: heated strongly, these terpenes break down and release benzene and methacrolein, a lung irritant. The higher the temperature, the more of them form.
Read the ingredients
A flower doesn't need added terpenes. For a vape, look for the exact nature of the flavourings.
Ask for the analysis
A serious product comes with a certificate of analysis per batch. Some include the terpene profile.
Avoid overheating
On a vaporiser or a pod, a moderate temperature preserves the taste and limits terpene breakdown.
In practice
Choose by nose, store somewhere cool.
Terpenes are fragile: the most volatile ones drop during drying and storage, and they break down faster with light, heat and air. A flower that hardly smells of anything has often lost part of its monoterpenes. To keep the taste, use an airtight, opaque jar, filled as close to the top as possible, stored somewhere cool and dry.
- Trust your nose for taste: it's the best guide to a flower's aroma profile.
- Don't rely on the strain name alone: the profile can change from batch to batch.
- Check the stated cannabinoid level: that's what tells you about intensity, not the smell.
- Start low with any new product, and never before driving.
If you love citrus notes, Cali Mochi Delta-P and the Lemon Mousseux resin play in that lemony register. They're products from our Delta-P range, CBDX-based, under 0.3% THC and lab-tested: the framework is explained on our Delta-P page. All our flowers, with their aroma profiles, are in the Delta-P flowers collection.
Your questions
What people ask us about terpenes.
What are terpenes?
Terpenes are aromatic molecules made by plants. In cannabis, they're produced in the trichomes, alongside the cannabinoids, and give each flower its smell and taste. More than 200 have been described in the plant.
What are the main terpenes in cannabis?
The most common are myrcene (earthy), limonene (citrus), alpha-pinene (pine), linalool (floral, lavender) and beta-caryophyllene (peppery). Humulene, which is woodier, also comes up often.
Do terpenes have effects?
They determine the smell and taste. As for effects, the data mostly comes from animal or lab studies: associations like "lemon = energy" are reputations, not facts proven in humans.
What does myrcene smell like?
Earthy, musky and herbal, with a fruity touch. It's often the most abundant terpene in cannabis, and it's also found in hops.
Do terpenes get you high?
No. Terpenes aren't cannabinoids and none of them produces an effect like THC's. Beta-caryophyllene acts on the CB2 receptor, but with no psychoactive effect according to published research.
What is the entourage effect?
The hypothesis that cannabis compounds, cannabinoids and terpenes, work better together than apart. It hasn't been proven: a 2020 study found no direct effect of terpenes on CB1 and CB2 receptors.
Are added terpenes dangerous?
Terpenes are common food flavourings. The documented risk comes from heat: heated very strongly, especially when dabbing, they can break down and release irritating compounds such as methacrolein or benzene. A moderate temperature limits this risk.
Why don't two flowers with the same strength taste the same?
Because the cannabinoid level says nothing about the terpene profile. Two flowers with the same strength can carry very different terpenes, and so very different aromas.
Sources
The references cited in this article.
- Russo E. B., British Journal of Pharmacology (2011). Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects.
- Hanuš L. O., Hod Y., Medical Cannabis and Cannabinoids (2020). Terpenes/Terpenoids in Cannabis: Are They Important?
- Gertsch J. et al., PNAS (2008). Beta-caryophyllene is a dietary cannabinoid.
- Finlay D. B. et al., Frontiers in Pharmacology (2020). Terpenoids From Cannabis Do Not Mediate an Entourage Effect by Acting at Cannabinoid Receptors.
- Smith C. J. et al., PLOS One (2022). The phytochemical diversity of commercial Cannabis in the United States.
- Meehan-Atrash J. et al., ACS Omega (2017). Toxicant Formation in Dabbing: The Terpene Story.
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