Ocimene

Ocimene at a Glance

Ocimene is a naturally occurring acyclic monoterpene hydrocarbon (3,7-dimethyl-1,3,6-octatriene) with a light, sweet, herbaceous and faintly woody-citrus aroma. It occurs throughout the plant kingdom — in tarragon, sweet basil (from whose genus Ocimum it takes its name), mint, hops, mango, lavender and the floral scent of a large share of flowering plants — and it is a common minor-to-moderate component of essential oils used in flavour and fragrance work ^{1,5Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →}.

What makes ocimene distinctive is not a drug profile but an ecological one. It is one of the best-characterised plant semiochemicals: a herbivore-induced volatile that plants release when attacked (recruiting the predators and parasitoids of their attackers) and a floral volatile that attracts a broad range of pollinators ^{1Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →}. This is what plants make it for.

Its therapeutic reputation — anti-inflammatory, antifungal, anticonvulsant — is real but rests almost entirely on whole β-ocimene-rich essential oils, in which ocimene is one active molecule among many. Direct evidence for the isolated compound is limited to a single recent rodent study, and there are no human trials of isolated ocimene ^{5,6,7Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →Reference 7Laraib I et al. · 2025Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathwaysView study →}. It is a low-toxicity, GRAS food and fragrance volatile.

Ocimene as a Plant Semiochemical

The most substantial, best-evidenced thing about ocimene is its role in plant chemical ecology — this is where the real body of research sits, and it is distinctive to this molecule. Ocimene is a key floral and foliar volatile involved in multiple interactions between plants and other organisms, from pollinators to herbivores to the natural enemies of those herbivores ^{1Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →}.

Herbivore-Induced Defence Volatile

When a plant is attacked by chewing or sap-feeding insects, ocimene emission rises sharply from both damaged and neighbouring undamaged tissue. Its production is switched on by the jasmonic-acid and salicylic-acid signalling that governs plant defence, so it functions as a marker and mediator of the induced-defence state ^{1,3Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →Reference 3Huang X et al. · 2022Functional characterization of a terpene synthase responsible for (E)-β-ocimene biosynthesis identified in Pyrus betuleafolia transcriptome after herbivoryView study →}. Two consequences follow. First, the volatile helps establish tritrophic (indirect) defence: the released blend attracts the predators and parasitoids of the herbivores, so the plant recruits bodyguards rather than fighting the insect directly ^{1Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →}. Second, ocimene can act more directly — treating Chinese cabbage with β-ocimene slowed the growth and reproduction of the peach aphid Myzus persicae, disrupted its feeding, and up-regulated the plant’s own defence-marker genes and glucosinolates, while inducing detoxification enzymes (CYP6CY3, GST) in the aphids themselves ^{2Reference 2Kang ZW et al. · 2018Volatile β-ocimene can regulate developmental performance of peach aphid Myzus persicae through activation of defense responses in Chinese cabbage Brassica pekinensisView study →}.

Pollinator Attraction

In flowers, ocimene plays the opposite, attractive role. It is present in the floral scent of roughly 47% of surveyed plant species and about three-quarters of surveyed families, and it behaves as a generalist pollinator attractant — it can attract honeybees and bumblebees, and its emission follows the daily and spatial rhythms typical of scent signals tuned to pollinator activity ^{1Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →}. That a single molecule serves as both a “come here” signal to pollinators and a “danger” signal in the defence context is exactly why its biology is more interesting than its pharmacology.

Isomers & Biosynthesis

Ocimene is not one compound but a small family of double-bond isomers: β-ocimene (3,7-dimethyl-1,3,6-octatriene) exists as (E)-/trans- and (Z)-/cis- forms, the trans isomer being the more abundant in floral scent; α-ocimene and allo-ocimene (a heat/air-rearrangement product) are related conjugated trienes. It is built in the plastid from the universal monoterpene precursor geranyl diphosphate (GPP) by (E)-β-ocimene synthases — terpene synthases characterised first in the scented flowers of snapdragon, where the same enzyme family also makes myrcene ^{4Reference 4Dudareva N et al. · 2003Dudareva N, Martin D, Kish CM, et al. (2003). (E)-β-ocimene and myrcene synthase genes of floral scent biosynthesis in snapdragon: function and expression of three terpene synthase genes of a new terpene synthase subfamily. The Plant Cell. https://pubmed.ncbi.nlm.nih.gov/12724546/View study →}, and later in vegetative tissue of species such as wild pear, where a herbivore-inducible ocimene synthase is switched on after insect attack ^{3Reference 3Huang X et al. · 2022Functional characterization of a terpene synthase responsible for (E)-β-ocimene biosynthesis identified in Pyrus betuleafolia transcriptome after herbivoryView study →}.

What It's Used For

Ocimene’s medicinal profile is modest and, crucially, mostly attributable to whole oils rather than the isolate. The evidence splits by whether the thing tested was purified ocimene (rare) or a β-ocimene-rich essential oil in which ocimene is one of several actives (usual).

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. Almost all of it is whole-oil evidence with a single isolate study, so scores stay low by design.

01Anti-inflammatory / antihyperalgesicShaky34%One rodent isolate study (TLR4/pyroptosis, gastroprotection) + β-ocimene-rich oil ↓ NO in macrophages ^{6,7Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →Reference 7Laraib I et al. · 2025Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathwaysView study →}

02Antimicrobial / antifungalShaky24%Whole β-ocimene-rich oils active against fungi/dermatophytes; no isolate MIC ^{1,6Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →}

03Anticonvulsant / sedativeShaky22%Whole tarragon EO (ocimene-major) anti-seizure in rodents; effect not assigned to ocimene ^{5Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →}

Mechanisms

The load-bearing point: only the top two rows are the isolated molecule, and both come from one study. The remainder is whole-oil pharmacology or plant biology.

Pharmacokinetics

Ocimene is a small, highly lipophilic, volatile hydrocarbon with no oxygen functionality, so it is expected to be readily absorbed and rapidly distributed, cleared and exhaled — the general behaviour of monoterpene hydrocarbons. Beyond that, its human ADME is essentially uncharacterised: there are no published Cmax, half-life, oral-bioavailability or metabolite data for the isolate, and the one rodent efficacy study dosed it orally without reporting kinetics ^{7Reference 7Laraib I et al. · 2025Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathwaysView study →}. Practically, its volatility and tendency to oxidise/rearrange (β-ocimene converts to allo-ocimene on heating and air exposure) mean the “dose” delivered from an essential oil is unstable and hard to standardise.

Clinical Trials

There are no controlled human trials of isolated ocimene. The human-relevant evidence is dietary/aromatic exposure and whole-oil work; the isolate evidence is preclinical.

Last checked: July 2026.

Isolate vs. Plant Studies

Ocimene is a textbook case of the compound-page caveat. Almost all of the bioactivity evidence is whole essential oil, not the purified molecule: the anticonvulsant data are tarragon oil ^{5Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →}, the anti-inflammatory/antifungal data are water-dropwort oil ^{6Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →}, and ocimene is invariably one of several monoterpenes present. Only the 2025 rodent study tested purified ocimene directly, and it is a single report ^{7Reference 7Laraib I et al. · 2025Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathwaysView study →}. The one research area where the molecule itself is the object of deep study is chemical ecology — its role as a herbivore-induced and floral volatile — but that is plant biology, not human pharmacology ^{1,2Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →Reference 2Kang ZW et al. · 2018Volatile β-ocimene can regulate developmental performance of peach aphid Myzus persicae through activation of defense responses in Chinese cabbage Brassica pekinensisView study →}. The correct framing: interesting, well-studied semiochemistry; thin, mostly whole-oil therapeutics; and no human clinical data on the isolate.

Prevalence in Nature

Ocimene is one of the most widespread plant volatiles, reported from the floral scent of roughly 47% of surveyed species and about three-quarters of surveyed plant families, plus a great many vegetative tissues and essential oils ^{1Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →}. It typically occurs as a minor component, but climbs to a major fraction of certain oils — around 20% of tarragon (Artemisia dracunculus) essential oil (as α-trans-ocimene) ^{5Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →} and over 30% of water-dropwort (Oenanthe crocata) oil (as trans-β-ocimene, with a further ~12% cis) ^{6Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →}. It commonly co-occurs with sibling monoterpenes such as myrcene, limonene, linalool, α-pinene and β-pinene.

Major Natural Sources

Source	Plant part	Reported ocimene content
Water dropwort (Oenanthe crocata)	aerial essential oil	~31% trans-β (+ ~12% cis-β)
Tarragon (Artemisia dracunculus)	aerial essential oil	~20% α-trans-ocimene
Sweet basil (Ocimum basilicum)	leaf/flower oil	minor–moderate
Mango (Mangifera indica)	fruit/leaf volatiles	minor
Hops (Humulus lupulus)	cone oil	minor

These figures are the percentage of the essential oil, not of the whole plant, and shift substantially with chemotype, plant part and extraction method ^{1,5,6Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →}.

Other Reported Sources

Ocimene is also reported from:

• Orchids and many other scented flowers
• Lavender
• Peppermint and other mints
• Bergamot
• Black pepper
• Kumquat
• Cannabis

Discovery & Synthesis

Ocimene’s name derives from basil, genus Ocimum, the plant in whose volatile oil it was characterised as a constituent; a precise first-isolation date and a first total synthesis are not well documented in the accessible literature, in keeping with its long-standing status as a common, unremarkable essential-oil terpene rather than a targeted drug. Today it is encountered almost entirely as a natural essential-oil constituent in flavour and fragrance materials rather than as a manufactured isolate; because it is volatile and prone to oxidation and to isomerising toward allo-ocimene, purified ocimene is chemically less convenient than more stable terpenes, and it is used and sold chiefly as part of whole oils.

Patents: not yet researched.

Toxicity & Safety

Ocimene is a common, naturally occurring monoterpene of foods and essential oils and is regarded as low in toxicity at those levels; it is used as a flavour and fragrance ingredient (GRAS-status food volatile). As with all light terpene hydrocarbons, the concentrated material is volatile and flammable, and — being an unsaturated triene — it oxidises and isomerises on exposure to air, heat and light, so aged or oxidised oils are chemically different from fresh ones and, like other oxidised terpenes, may be more skin-irritating or sensitising. “Natural” does not mean “harmless” for concentrated essential oils, whose exposure is far higher than the trace amounts in food.

Direct isolate safety data are sparse: the single rodent pharmacology study reported ocimene to be gastric-protective rather than irritating at the doses used ^{7Reference 7Laraib I et al. · 2025Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathwaysView study →}, but no comprehensive repeat-dose, genotoxicity or reproductive-toxicity package for the pure compound is characterised here. Human reproductive/developmental data for isolated ocimene are not established; pregnancy and lactation are a per-herb / per-supplement decision made on the herb or product page where intake is decided, not on this molecule page.

Safety at a Glance

✅ Low / no toxicity

• Low-toxicity food & fragrance volatile. A widespread, GRAS essential-oil monoterpene consumed in the diet and used in flavour/fragrance at low levels ^{1Reference 1Farré-Armengol G et al. · 2017Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/View study →}.
• Concentrated oil is volatile, flammable and oxidation-prone. As an unsaturated triene it oxidises and isomerises (toward allo-ocimene) with air, heat and light — aged oils differ from fresh.
• Essential oils ≫ whole herbs for meaningful exposure; oxidised terpene oils can irritate or sensitise skin.
• Isolate human data are absent. Therapeutic claims rest on whole oils or a single rodent study; pregnancy/lactation for isolated ocimene is not established and is decided at the herb/product level.

Dosage

There is no established or recommended human dose for isolated ocimene. The only quantitative efficacy figures are preclinical rodent research doses of the purified compound ^{7Reference 7Laraib I et al. · 2025Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathwaysView study →} or of β-ocimene-rich whole oils ^{5,6Reference 5Sayyah M et al. · 2004Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oilView study →Reference 6Valente J et al. · 2013Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oilView study →}, and these are not convertible to human self-dosing. Real human exposure is:

• Foods, herbs and spices (a common natural flavour volatile)
• Essential oils used in flavour and fragrance
• Inhaled aromatherapy oils
• Diluted topical essential oils

These are doses studied in research and levels of ordinary exposure, not a personal recommendation.

References

1. Farré-Armengol G, Filella I, Llusià J, Peñuelas J (2017). β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms. Molecules. https://pubmed.ncbi.nlm.nih.gov/28703755/
2. Kang ZW, Liu FH, Zhang ZF, et al. (2018). Volatile β-ocimene can regulate developmental performance of peach aphid Myzus persicae through activation of defense responses in Chinese cabbage Brassica pekinensis. Frontiers in Plant Science. https://pubmed.ncbi.nlm.nih.gov/29892310/
3. Huang X, Zhang H, Li H, et al. (2022). Functional characterization of a terpene synthase responsible for (E)-β-ocimene biosynthesis identified in Pyrus betuleafolia transcriptome after herbivory. Frontiers in Plant Science. https://pubmed.ncbi.nlm.nih.gov/36479507/
4. Dudareva N, Martin D, Kish CM, et al. (2003). (E)-β-ocimene and myrcene synthase genes of floral scent biosynthesis in snapdragon: function and expression of three terpene synthase genes of a new terpene synthase subfamily. The Plant Cell. https://pubmed.ncbi.nlm.nih.gov/12724546/
5. Sayyah M, Nadjafnia L, Kamalinejad M (2004). Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oil. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/15325732/
6. Valente J, Zuzarte M, Gonçalves MJ, et al. (2013). Antifungal, antioxidant and anti-inflammatory activities of Oenanthe crocata L. essential oil. Food and Chemical Toxicology. https://pubmed.ncbi.nlm.nih.gov/24012643/
7. Laraib I, Qasim S, Uttra AM, Al-Joufi FA (2025). Anti-inflammatory, antihyperalgesic, and gastric safety profiling of ocimene: attenuation of NSAID-induced gastric ulcers by modulating Toll-like receptor 4 and pyroptosis pathways. ACS Pharmacology & Translational Science. https://pubmed.ncbi.nlm.nih.gov/40109750/

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