Understanding Terpenes in Cannabis: The Role of Limonene

Limonene in Medicinal Cannabis: What This Citrus Terpene Really Does

Limonene is the bright, citrusy terpene that gives lemons, oranges and many cannabis strains their “zesty” aroma. It is often marketed as the “uplifting” or “daytime” terpene, but the real science is more nuanced. This article walks through what limonene is, what the research actually shows, and how it might fit into a medicinal cannabis plan. It is general information only and not a substitute for individual medical advice.

Key takeaways

• Limonene is a citrus-scented terpene found in cannabis, citrus peels and many essential oils. It is widely used as a flavouring and fragrance ingredient in foods, cosmetics and cleaning products.[1,2]

• Most of the evidence for limonene’s mood and “calming” effects comes from laboratory and animal studies. These suggest anti-inflammatory, analgesic (pain-modulating), antioxidant and possible antidepressant- or anxiolytic-like (anxiety-modulating) actions.[1,2,6–8]

• Human data are still limited but growing. A recent trial in healthy adults found that vapourised d-limonene reduced THC-induced anxiety without blunting other THC effects, which supports a genuine entourage-style interaction.[3]

• Reviews suggest limonene may contribute to pain relief mainly in inflammatory and neuropathic pain models, likely by dampening inflammatory signalling and oxidative stress, rather than acting as a strong stand-alone analgesic.[2,4,5]

• Toxicology and food-safety assessments generally regard limonene as low-risk at typical food and fragrance exposure levels, although oxidised limonene can irritate the skin or airways in susceptible people.[1,2,7]

What is limonene?

Limonene (usually d-limonene in nature) is a monoterpene that gives citrus peels their sharp, fresh smell.[1]

You will find limonene in:

• Citrus fruits such as lemon, orange, lime and grapefruit

• Some herbs and spices

• Many essential oils and perfumes

• Cleaning products and fragranced household items

• Flavoured foods and drinks

In cannabis, limonene is a common terpene on lab reports. Products described as “lemon”, “citrus” or “tangy” often have limonene near the top of the terpene profile, although aroma is not a perfect guide.[1,4]

Broad pharmacology reviews describe limonene as having antimicrobial, anti-inflammatory, antioxidant, antinociceptive (pain-modulating), and potential anticancer and neuroprotective properties, mostly based on preclinical work.[1,2,6–8]

From a regulatory perspective, limonene has been evaluated extensively as a food flavouring and fragrance ingredient. At typical exposure levels from foods and consumer products, expert committees have concluded that d-limonene does not pose a safety concern for the general population.[1,2]

Terpenes and the entourage effect in cannabis

Terpenes are aromatic compounds produced by many plants, including cannabis, citrus, pine and lavender. They shape flavour and scent and, in cannabis, may also contribute to how a product feels.[4]

In cannabis, terpenes sit alongside cannabinoids such as THC and CBD. Together, these compounds may contribute to the “entourage effect”, the idea that cannabinoids, terpenes and other plant molecules work together to shape the overall effect rather than acting alone.[4,5]

If you would like a refresher before going deeper into limonene:

• We unpack the entourage concept in more detail in our article on THC strength and the entourage effect.

• For cannabinoid basics, see our primer on cannabinoids (THC, CBD, CBC, CBG and CBN).

• If you are comparing terpene profiles, you might also like our deep dives on caryophyllene and myrcene.

• For the practical side, we explain why temperature matters in our article on terpenes and vaporiser temperature and show you how to get started in our guide to using a dry herb vaporiser.

Limonene, mood and anxiety

Limonene is often described as the “feel-good” terpene that might make a product feel bright or daytime friendly. That reputation comes mainly from animal studies and a small but growing amount of human data.

Preclinical mood and anxiety data

In animal and laboratory models, limonene and limonene-rich citrus oils have shown:

• Antidepressant-like effects in chronic stress models, with improvements in behaviour and changes in neurotransmitters such as serotonin, noradrenaline and dopamine.[6–8]

• Anxiolytic-like (anxiety-reducing) effects in mice, including better performance in standard anxiety tests that appear to involve GABAergic and related pathways.[6–8]

These results suggest limonene may support mood and stress responses in preclinical settings, but they use doses and exposure patterns that do not directly translate into human dosing.

Human data: limonene and THC-related anxiety

The most relevant human evidence so far is a 2024 double-blind, placebo-controlled study in healthy adults who intermittently use cannabis.[3] Participants inhaled vapourised THC either alone or with added d-limonene.

In this study:[3]

• THC alone increased anxiety for some participants.

• When d-limonene was added, ratings of anxiety and paranoia with THC were significantly lower in a dose-dependent way.

• Limonene did not blunt the overall “high”, cognitive effects or vital-sign changes from THC, and limonene on its own looked similar to placebo.

This suggests limonene can selectively soften THC-related anxiety without simply diluting THC, which is a real-world example of the entourage effect. More studies are needed in clinical populations, but it is a promising signal.

Limonene, pain and inflammation

Limonene is not usually the headline terpene for pain, but it has been studied in several inflammatory and neuropathic pain models.

Preclinical and review data suggest that limonene can:[2,4,5]

• Reduce pro-inflammatory cytokines and oxidative stress in tissues

• Influence glial and neuronal signalling in chronic pain pathways

• Provide analgesic effects mainly in inflammatory and neuropathic pain models rather than brief, simple acute pain

A recent review of cannabis terpenes in chronic pain concluded that limonene is most realistic as an adjuvant, helping with mood, inflammation and the overall pain experience rather than acting as a stand-alone analgesic for moderate or severe pain.[4,5]

For patients, the practical message is that limonene is best seen as a supporting player that may complement cannabinoids and other pain treatments, not as the primary pain ingredient on its own.

How limonene may interact with THC and other cannabinoids

The claim that “terpenes change how THC feels” appears often in marketing. Underneath that, there is a plausible scientific basis, particularly for limonene.

Reviews of limonene and other terpenes suggest several possible mechanisms for interaction with cannabinoids:[1–5]

• Pharmacodynamic interactions, where terpenes act on overlapping receptor systems such as serotonin, GABA and adenosine that intersect with the endocannabinoid system

• Effects on neuroinflammation and oxidative stress, which can influence mood, pain perception and overall brain state

• Possible pharmacokinetic effects, such as changes in absorption or distribution, although human data here are limited

The 2024 THC plus limonene study is helpful because it shows a specific, selective effect. Limonene reduced THC-induced anxiety without flattening THC’s other effects.[3] That is different to simply lowering the THC dose.

In practice, this supports the idea that the full cannabinoid and terpene profile matters more than any single number on the label. Our article on THC strength and the entourage effect and our cannabinoid overview unpack these interactions in more depth.

Safety and side effects

General safety profile

Because limonene is used widely in foods, fragrances and household products, it has been reviewed extensively by toxicology and food-safety bodies.[1,2,6,7]

Overall, these reviews suggest that:

• At doses matching or exceeding typical flavouring use, limonene shows favourable margins of safety in animal and human data.[1,2]

• Very high doses in certain rodent strains can produce kidney changes and tumour findings, especially in male rats, but the mechanisms appear to be species specific and are not considered relevant at normal human exposure levels.[1,6]

• Oxidised limonene, for example in old or poorly stored fragrances, can act as a skin and airway sensitiser in susceptible individuals.[2,7]

Practical implications for medicinal cannabis

When limonene is present as part of a cannabis product:

• Most side effects are still driven by THC, such as dizziness, dry mouth, anxiety, impaired driving and cognitive changes. Limonene does not remove those risks.

• Limonene-rich profiles may feel more bright or daytime friendly for some people, and early data suggest they may reduce THC-related anxiety in some users, but this is not guaranteed.[3]

• As with any inhaled or vapourised compound, there is a risk of airway irritation, particularly in people with asthma or chronic lung disease.

• People with a history of fragrance or citrus peel allergy should be careful, especially with topicals or heavily scented products.

If you are pregnant or breastfeeding, have a history of psychosis or problematic substance use, or have complex medical conditions, it is important to discuss medicinal cannabis with a doctor who understands both potential benefits and risks in your situation.

How limonene might influence product choice

For most patients, the key decisions are still about:

• What you are trying to treat (for example, pain, anxiety, sleep, spasticity)

• Which cannabinoids are likely to help (for example, THC dominant versus a more balanced THC:CBD product)

• How you will use it (oils, capsules, vapourised flower and so on)

Terpenes like limonene then add a finer level of tuning once those basics are in place.

Points to consider and discuss with your prescriber:

• Look beyond THC percentage. For some people, a moderate THC product with a supportive terpene profile such as limonene, caryophyllene and myrcene can be more helpful and more tolerable than a very high THC product with minimal terpene diversity.[4,5]

• Match timing to effect where possible. Many patients informally report that limonene-rich profiles feel more suitable for daytime, while myrcene-heavy profiles feel heavier or more sedating in the evening. Your own response may differ, so it is worth keeping track.

• Route and temperature matter. Vapourising dried flower with a temperature-controlled dry herb vaporiser rather than smoking can deliver terpenes differently and often more consistently. If you are using flower, see our article on terpenes and vaporiser temperature and our step-by-step guide to using a dry herb vaporiser.

• Keep a simple log. Recording product, dose, time, route, aroma, effects and side effects can be very helpful when you and your doctor are fine tuning treatment.

If you are new to medicinal cannabis generally, our overview of medicinal cannabis online and our FAQ cover many common questions about access, safety and day to day use.

Pricing, access and next steps in Australia

Cost and access are major practical considerations. Legal medicinal cannabis in Australia is often more accessible, and sometimes more affordable, than many people expect.

• We break down pricing, dose ranges and ways to keep treatment sustainable in our guide to cheap medical cannabis.

• For a straightforward overview of pathways, approvals and what to expect from an appointment, see our page on medicinal cannabis online.

• Many common questions around driving, workplace testing and safety are covered in our FAQ.

If you feel ready to get personalised advice, you can book an appointment with a doctor experienced in this area. That is the safest way to decide whether a limonene-rich product might make sense for you and how it would fit into your broader treatment plan.

References

1. Vieira AJ, Beserra FP, Souza MC, Totti BM, Rozza AL. Limonene: Aroma of innovation in health and disease. 2018.

2. Chen X, et al. The pharmacological effects and potential applications of limonene from citrus plants: a review. 2024.

3. Spindle TR, Zamarripa CA, Russo E, et al. Vaporized d-limonene selectively mitigates the acute anxiogenic effects of Δ9-tetrahydrocannabinol in healthy adults who intermittently use cannabis. Drug Alcohol Depend. 2024;257:111267.

4. Alfieri A, et al. A review of cannabis terpenes in chronic pain syndromes. Pharmaceuticals. 2025.

5. Schwarz AM, et al. Terpenes from Cannabis sativa induce antinociception in a neuropathic pain model via adenosine A2A receptors. 2023.

6. Devi N, et al. From citrus to clinic: limonene’s journey through preclinical research, clinical trials and formulation innovations. 2025.

7. Eddin LB, et al. Neuroprotective potential of limonene and its metabolites: a review. 2021.

8. Anandakumar P, et al. D-limonene: a multifunctional compound with chemopreventive and therapeutic potential. 2021.EO, and keep the rest as normal paragraph text.