What is Limonene?
Limonene (C₁₀H₁₆) is a terpene found in citrus fruit rinds, cannabis, rosemary and peppermint. In cannabis, it contributes to the characteristic aroma and may modulate pharmacological effects through the proposed entourage effect.
Aroma: Bright, citrusy, lemon/orange — one of the most recognisable terpene aromas.
Pharmacological Properties
Monocyclic monoterpene with demonstrated anti-anxiety, antidepressant and antifungal properties in preclinical models. Activates serotonin (5-HT1A), dopamine and adenosine receptors. Anxiolytic effects shown in rodent models. Also a natural antifungal — may contribute to cannabis disease resistance.
Relevance in Cannabis
Typically the second or third most abundant terpene in citrus-forward cannabis cultivars, at 5–30% of total terpenes. Contributes to bright, uplifting character. Highly volatile — degrades readily during heat-based extraction and decarboxylation.
GMP and Manufacturing Relevance
If terpene preservation is a product objective, low-temperature extraction and processing parameters must be validated. Limonene quantification should be included in terpene profile specifications for full-spectrum products.
Analytical Measurement
Terpene profiling is performed by headspace GC-MS or GC-FID. Validated methods should achieve quantitative separation of key terpenes. Where terpene content is a product specification parameter, the analytical method must be validated under ICH Q2(R1).
See the Cannabis Glossary for definitions of related cultivation, extraction and quality terms.
References
- d'Alessio PA et al. Anti-stress effects of d-limonene and its metabolite. Rejuvenation Res. 2014.
- Russo EB. Taming THC. Br J Pharmacol. 2011.