Nerol

Nerol at a Glance

Nerol is an acyclic monoterpene alcohol and the cis (Z) isomer of geraniol, found in rose, neroli, lemongrass and citrus oils.

The geometric difference gives it a softer, fresher rose scent than geraniol, which is why perfumery treats them as distinct materials despite their near-identical composition. It is GRAS as a flavour and fragrance ingredient, and its isolate evidence is entirely preclinical.

Nerol vs. Geraniol

Nerol and geraniol are the same molecule folded two ways: one carbon chain, one alcohol, one double bond drawn cis in nerol and trans in geraniol. That single geometric difference is what perfumery buys and what the pharmacology has largely ignored.

	Geraniol	Nerol
Geometry at the 2,3-double bond	trans (E)	cis (Z)
Scent	full, sweet rose	fresher, greener, lighter rose
Boiling point	higher	lower — the pair is separated by fractional distillation
Where it leads	palmarosa, rose, geranium — the dominant alcohol	neroli, rose, immortelle — always the minor partner
Aldehyde	geranial	neral; together they are citral
Ester chemistry	geranyl acetate	neryl acetate and the rarer neryl esters of immortelle 11,12Reference 11Leonardi M et al. · 2013Essential-oil composition of Helichrysum italicum (ROTH) G.DON ssp. italicum from Elba Island (Tuscany, Italy) — GC-MS composition studyView study →Reference 12Djihane B et al. · 2017In vitroChemical constituents of Helichrysum italicum (Roth) GView study →
Human data	one RCT (IBS), human metabolism study	none
Made from	myrcene, citral	the same routes — nerol and geraniol come out together 14,15Reference 14Behr A · 2009ReviewMyrcene as a natural base chemical in sustainable chemistry: a critical review — reviewView study →Reference 15Surendran S et al. · 2021ReviewMyrcene-What Are the Potential Health Benefits of This Flavouring and Aroma Agent? — reviewView study →

The two interconvert under acid and heat, which is why commercial “geraniol” and “nerol” grades are defined by their isomer ratio rather than by purity, and why a plant that makes one usually carries some of the other. It is also why the pharmacology deserves caution: nerol’s antifungal, organ-protective and cognitive studies were run on nerol alone, never against geraniol as a comparator ^{1,3,6,8Reference 1Wang Z et al. · 2020In vitroActivities of nerol against Candida albicans in vitro and in vivoView study →Reference 3Tian J et al. · 2018Nerol-induced apoptosis associated with ROS generation and Ca²⁺ overload in Aspergillus flavusView study →Reference 6Mondal M et al. · 2023AnimalProtective effects of nerol against carbon-tetrachloride liver toxicity in Sprague-Dawley ratsView study →Reference 8Yang J et al. · 2026AnimalNerol ameliorates cognitive dysfunction in vascular-dementia rats by inhibiting mitochondrial oxidative stressView study →}, so whether the cis geometry changes anything biologically — as opposed to olfactorily — is unknown. The one thing the comparison does establish is that the human evidence belongs to geraniol.

What It's Used For

Nerol is an acyclic monoterpene alcohol and the cis (Z) isomer of geraniol — distinct from neral (the corresponding aldehyde) and from nerolidol (a sesquiterpene). It carries a soft, sweet, rose-like scent and is a high-volume GRAS flavor and fragrance ingredient. There is a modest but real body of nerol-isolate preclinical work — antifungal being the deepest — but the honest headline holds: no human trials, no dedicated pharmacokinetic study, and much surrounding literature is essential-oil-level. All efficacy evidence is in-vitro or rodent.

Evidence by IndicationStrength of support · Beta

01AntifungalShaky42%Broad in-vitro + one mouse model + defined mechanism ^{1,2,3Reference 1Wang Z et al. · 2020In vitroActivities of nerol against Candida albicans in vitro and in vivoView study →Reference 2Ji J et al. · 2024Nerol as a novel antifungal agent: inhibitory effects on Fusarium oxysporum, Pestalotiopsis neglecta and Valsa maliView study →Reference 3Tian J et al. · 2018Nerol-induced apoptosis associated with ROS generation and Ca²⁺ overload in Aspergillus flavusView study →}

02Antibacterial / anti-quorum-sensingShaky32%In-vitro panels, one mouse infection model, synergy ^{4,5Reference 4Lu Q et al. · 2026Nerol as an anti-quorum-sensing and therapeutic agent against Acinetobacter baumannii pneumonia. iScience. https://pubmed.ncbi.nlm.nih.gov/42063562/View study →Reference 5Kasthuri T et al. · 2022Synergistic antiseptic property of carvacrol and nerol against nosocomial pathogensView study →}

03Antioxidant / organ-protectionShaky28%Rodent liver and heart protection models ^{6,7Reference 6Mondal M et al. · 2023AnimalProtective effects of nerol against carbon-tetrachloride liver toxicity in Sprague-Dawley ratsView study →Reference 7He ML et al. · 2025AnimalNerol attenuates doxorubicin-induced heart failure by inhibiting cardiomyocyte apoptosis in ratsView study →}

04CNS / cognitiveShaky18%A single rodent vascular-dementia study ^{8Reference 8Yang J et al. · 2026AnimalNerol ameliorates cognitive dysfunction in vascular-dementia rats by inhibiting mitochondrial oxidative stressView study →}

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Mechanisms

Only the membrane-disruption and mitochondrial/ROS/Ca²⁺ actions are reproduced across multiple studies; the rest are single-report mechanisms.

Pharmacokinetics

No dedicated pharmacokinetic study of isolated nerol exists — a genuine gap. As the cis isomer of geraniol, its ADME is inferred, not measured: expected to be highly volatile, rapidly absorbed and rapidly cleared via allylic oxidation to acidic metabolites (nerolic/geranic-acid-type products), with short systemic residence and low sustained exposure — the same limitation that constrains geraniol. This inferred profile is the central caveat separating nerol’s in-vitro/topical potency from any systemic use.

Clinical Trials

There are no human trials of isolated nerol for any indication, and no registered study. Human exposure is at flavouring and fragrance levels, assessed for safety by RIFM ^{9Reference 9Api AM et al. · 2023RIFM fragrance ingredient safety assessment, nerol, CAS 106-25-2View study →} but never for effect. All efficacy evidence is in vitro or rodent.

Last checked: September 2026.

Isolate vs. Plant Studies

Nerol’s literature is, unusually for a fragrance terpene, mostly the isolate — but only because so little of it is about the plants. The Candida work in vitro and in mice ^{1Reference 1Wang Z et al. · 2020In vitroActivities of nerol against Candida albicans in vitro and in vivoView study →}, the phytopathogen and Aspergillus mechanism studies ^{2,3Reference 2Ji J et al. · 2024Nerol as a novel antifungal agent: inhibitory effects on Fusarium oxysporum, Pestalotiopsis neglecta and Valsa maliView study →Reference 3Tian J et al. · 2018Nerol-induced apoptosis associated with ROS generation and Ca²⁺ overload in Aspergillus flavusView study →}, the Acinetobacter quorum-sensing and pneumonia model ^{4Reference 4Lu Q et al. · 2026Nerol as an anti-quorum-sensing and therapeutic agent against Acinetobacter baumannii pneumonia. iScience. https://pubmed.ncbi.nlm.nih.gov/42063562/View study →}, the carvacrol synergy ^{5Reference 5Kasthuri T et al. · 2022Synergistic antiseptic property of carvacrol and nerol against nosocomial pathogensView study →}, the liver, heart and vascular-dementia rodent studies ^{6,7,8Reference 6Mondal M et al. · 2023AnimalProtective effects of nerol against carbon-tetrachloride liver toxicity in Sprague-Dawley ratsView study →Reference 7He ML et al. · 2025AnimalNerol attenuates doxorubicin-induced heart failure by inhibiting cardiomyocyte apoptosis in ratsView study →Reference 8Yang J et al. · 2026AnimalNerol ameliorates cognitive dysfunction in vascular-dementia rats by inhibiting mitochondrial oxidative stressView study →} and the genotoxicity cell work ^{10Reference 10Silva BO et al. · 2021Genotoxicity induced by nerol using human PBMC and HepG2/C3A cells as a modelView study →} all dosed nerol itself.

What is missing is the other half. Neroli, rose and immortelle oils are the plants that carry nerol, and their aromatherapy and clinical reputations rest on linalool, citronellol–geraniol and the neryl esters respectively, not on nerol — which is a minor component in every one of them ^{11,12,13Reference 11Leonardi M et al. · 2013Essential-oil composition of Helichrysum italicum (ROTH) G.DON ssp. italicum from Elba Island (Tuscany, Italy) — GC-MS composition studyView study →Reference 12Djihane B et al. · 2017In vitroChemical constituents of Helichrysum italicum (Roth) GView study →Reference 13Verma RS et al. · 2011Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills — GC-MS composition studyView study →}. No plant study attributes an effect to nerol specifically, and no human study exists for the isolate. The honest reading: a small, genuinely isolate-based preclinical file with no plant-side or human corroboration, and the family’s source oils are described once, on the geraniol page.

Its Role in Plants

Most plants reach nerol by the same road as geraniol — geranyl diphosphate, a terpene synthase, the free alcohol — and then isomerise or oxidise it, which is why the two alcohols travel together and why the cis aldehyde neral accompanies geranial in every citral-type oil. But some plants build the cis geometry in at the start. Tomato glandular trichomes make their monoterpenes from neryl diphosphate, the cis isomer of geranyl diphosphate, produced by a cis-prenyltransferase that had been assumed to serve only the rubber and dolichol pathways ^{16Reference 16Schilmiller AL et al. · 2009Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate — plant biochemistry and geneticsView study →}; the discovery showed that the nerol skeleton has its own biosynthetic entry point, not merely a detour from geraniol.

In the plant nerol is a scent and a store. Neroli’s fresh top note and part of rose’s are nerol’s; immortelle accumulates it largely as neryl acetate and a series of longer neryl esters unique to the genus ^{11,12Reference 11Leonardi M et al. · 2013Essential-oil composition of Helichrysum italicum (ROTH) G.DON ssp. italicum from Elba Island (Tuscany, Italy) — GC-MS composition studyView study →Reference 12Djihane B et al. · 2017In vitroChemical constituents of Helichrysum italicum (Roth) GView study →}, the volatile reservoir that gives the everlasting flower its honey-and-hay smell. Its antifungal activity against Fusarium, Valsa and Aspergillus ^{2,3Reference 2Ji J et al. · 2024Nerol as a novel antifungal agent: inhibitory effects on Fusarium oxysporum, Pestalotiopsis neglecta and Valsa maliView study →Reference 3Tian J et al. · 2018Nerol-induced apoptosis associated with ROS generation and Ca²⁺ overload in Aspergillus flavusView study →} is the defensive face of the same chemistry.

Prevalence in Nature

Nerol is widespread but almost never dominant. Rose oil carries 4–10% beside far more citronellol and geraniol ^{13Reference 13Verma RS et al. · 2011Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills — GC-MS composition studyView study →}; immortelle (Helichrysum italicum) 3–13% free nerol plus 6–46% neryl acetate, the ester dominating the oil in most Mediterranean populations ^{11,12Reference 11Leonardi M et al. · 2013Essential-oil composition of Helichrysum italicum (ROTH) G.DON ssp. italicum from Elba Island (Tuscany, Italy) — GC-MS composition studyView study →Reference 12Djihane B et al. · 2017In vitroChemical constituents of Helichrysum italicum (Roth) GView study →}; neroli, the oil it was named from, is linalool-led with nerol as a minor partner, and is so scarce — world production is on the order of 1.5 tonnes a year, over 90% of it Tunisian and Moroccan — that adulteration is the analytical concern ^{17Reference 17Bonaccorsi I et al. · 2011Composition of Egyptian nerolì oil — GC-MS and chiral composition studyView study →}. Lemongrass, bergamot, bitter-orange peel and many citral-type oils carry trace nerol alongside neral. As with the whole family, the figures are shares of the oil and move with population, season and soil ^{12Reference 12Djihane B et al. · 2017In vitroChemical constituents of Helichrysum italicum (Roth) GView study →}.

Major Natural Sources

Source	Plant part	Reported nerol content
Immortelle (Helichrysum italicum)	aerial-parts oil	2.8–12.8% free nerol; neryl acetate 5.6–45.9% 11,12Reference 11Leonardi M et al. · 2013Essential-oil composition of Helichrysum italicum (ROTH) G.DON ssp. italicum from Elba Island (Tuscany, Italy) — GC-MS composition studyView study →Reference 12Djihane B et al. · 2017In vitroChemical constituents of Helichrysum italicum (Roth) GView study →
Damask rose (Rosa × damascena)	flower oil	4.0–9.6% 13Reference 13Verma RS et al. · 2011Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills — GC-MS composition studyView study →
Neroli (Citrus aurantium blossom)	flower oil	minor, behind linalool and linalyl acetate 17Reference 17Bonaccorsi I et al. · 2011Composition of Egyptian nerolì oil — GC-MS and chiral composition studyView study →

The family’s four defining oils — rose, geranium, palmarosa and citronella — are described on the geraniol page.

Other Reported Sources

• Lemongrass and other citral-type oils, as a trace companion of neral
• Bergamot and bitter-orange peel
• Hops, as a minor terpene alcohol

Discovery & Synthesis

Nerol is the youngest name in its family. Albert Hesse and Otto Zeitschel isolated it from neroli — bitter-orange blossom oil — and named it in 1902, in the second of their papers on the oil’s chemistry ^{18Reference 18Hesse A · 1902Ueber Orangenblüthenöl II — chemical isolationView study →}; geraniol had been known for thirty years, and nerol was recognised as its geometric isomer once the cis/trans relationship of the two was worked out. It has since served as a textbook example of geometric isomerism in a natural product.

Commercial nerol is not extracted from neroli, which could not supply it. It comes out of the same processes that make geraniol — from myrcene via geranyl/neryl chloride and the acetates, or by hydrogenating citral — as a cis/trans mixture that is fractionally distilled into geraniol- and nerol-rich cuts ^{14,15Reference 14Behr A · 2009ReviewMyrcene as a natural base chemical in sustainable chemistry: a critical review — reviewView study →Reference 15Surendran S et al. · 2021ReviewMyrcene-What Are the Potential Health Benefits of This Flavouring and Aroma Agent? — reviewView study →}.

Patents: not yet researched.

Commercial Production

Nerol is a high-volume rose material in its own right, used where a lighter, fresher rose note is wanted than geraniol gives, and it is the parent of neryl acetate and the nerol-derived “nerol oxide” family of fresh green notes. Its isomer ratio, not its purity, defines the commercial grade.

Toxicity & Safety

Nerol is GRAS at flavoring levels and judged safe at current fragrance use levels, so the real-world issue is skin, not systemic toxicity — it is an EU-labeled fragrance allergen and a mild sensitizer.

Safety at a Glance

✅ Low / no toxicityAllergy risk

• GRAS and assessed as safe at fragrance use levels. Systemic toxicity at flavoring exposure is low.
• A recognized fragrance contact allergen. Listed among the EU’s labeled fragrance allergens and a mild skin sensitizer.
• Avoid concentrated or supplemental use in pregnancy and lactation. Dietary and cosmetic amounts are a separate question.
• Undiluted material can irritate, and air-oxidation raises its allergenicity.
• In-vitro genotoxicity at high concentrations. Seen in human PBMC and HepG2/C3A cells — supraphysiologic, not evidence of harm at food or fragrance exposure.

Full Safety & Interactions Detail

Nerol (CAS 106-25-2) is a long-established FEMA/FDA GRAS flavoring and high-volume fragrance ingredient; the RIFM fragrance-ingredient safety assessment concluded it is safe at current use levels for the evaluated endpoints ^{9Reference 9Api AM et al. · 2023RIFM fragrance ingredient safety assessment, nerol, CAS 106-25-2View study →}, and systemic toxicity at flavoring exposure is low. Two caveats attach to it. First, nerol is a recognized fragrance contact allergen — included among the EU’s expanded list of labeled fragrance allergens — and a mild skin sensitizer; undiluted material can irritate, and air-oxidation raises allergenicity. Second, at higher concentrations in vitro it was genotoxic/cytotoxic in human PBMC and HepG2/C3A cells ^{10Reference 10Silva BO et al. · 2021Genotoxicity induced by nerol using human PBMC and HepG2/C3A cells as a modelView study →}; these are supraphysiologic findings, not evidence of harm at food or fragrance exposure, but they mean nerol is not simply “harmless.”

Dosage

There is no established human dose for isolated nerol, and nothing here is a recommendation. Human exposure is limited to food-flavoring (GRAS) and fragrance levels ^{9Reference 9Api AM et al. · 2023RIFM fragrance ingredient safety assessment, nerol, CAS 106-25-2View study →}; preclinical efficacy used rodent doses or in-vitro concentrations far above dietary intake. Any topical antimicrobial/antifungal use should account for its sensitizer status.

These are doses studied in research and are not a personal recommendation.

References

1. Wang Z, et al. (2020). Activities of nerol against Candida albicans in vitro and in vivo. Applied Microbiology and Biotechnology. https://pubmed.ncbi.nlm.nih.gov/32248438/
2. Ji J, et al. (2024). Nerol as a novel antifungal agent: inhibitory effects on Fusarium oxysporum, Pestalotiopsis neglecta and Valsa mali. Journal of Fungi (Basel). https://pubmed.ncbi.nlm.nih.gov/39452651/
3. Tian J, et al. (2018). Nerol-induced apoptosis associated with ROS generation and Ca²⁺ overload in Aspergillus flavus. Applied Microbiology and Biotechnology. https://pubmed.ncbi.nlm.nih.gov/29860589/
4. Lu Q, et al. (2026). Nerol as an anti-quorum-sensing and therapeutic agent against Acinetobacter baumannii pneumonia. iScience. https://pubmed.ncbi.nlm.nih.gov/42063562/
5. Kasthuri T, et al. (2022). Synergistic antiseptic property of carvacrol and nerol against nosocomial pathogens. Archives of Microbiology. https://pubmed.ncbi.nlm.nih.gov/36053368/
6. Mondal M, et al. (2023). Protective effects of nerol against carbon-tetrachloride liver toxicity in Sprague-Dawley rats. Heliyon. https://pubmed.ncbi.nlm.nih.gov/38125544/
7. He ML, et al. (2025). Nerol attenuates doxorubicin-induced heart failure by inhibiting cardiomyocyte apoptosis in rats. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/39672223/
8. Yang J, et al. (2026). Nerol ameliorates cognitive dysfunction in vascular-dementia rats by inhibiting mitochondrial oxidative stress. Brain Research Bulletin. https://pubmed.ncbi.nlm.nih.gov/41619816/
9. Api AM, et al. (2023). RIFM fragrance ingredient safety assessment, nerol, CAS 106-25-2. Food and Chemical Toxicology. https://pubmed.ncbi.nlm.nih.gov/37268086/
10. Silva BO, et al. (2021). Genotoxicity induced by nerol using human PBMC and HepG2/C3A cells as a model. Journal of Toxicology and Environmental Health, Part A. https://pubmed.ncbi.nlm.nih.gov/33761836/
11. Leonardi M, Ambryszewska KE, Melai B, et al. (2013). Essential-oil composition of Helichrysum italicum (ROTH) G.DON ssp. italicum from Elba Island (Tuscany, Italy) — GC-MS composition study. Chem Biodivers. https://pubmed.ncbi.nlm.nih.gov/23495152/
12. Djihane B, Wafa N, Elkhamssa S, et al. (2017). Chemical constituents of Helichrysum italicum (Roth) G. Don essential oil and their antimicrobial activity against Gram-positive and Gram-negative bacteria, filamentous fungi and Candida albicans — GC-MS composition and in vitro study. Saudi Pharm J. https://pubmed.ncbi.nlm.nih.gov/28725151/
13. Verma RS, Padalia RC, Chauhan A, et al. (2011). Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills — GC-MS composition study. Nat Prod Res. https://pubmed.ncbi.nlm.nih.gov/21711177/
14. Behr A, Johnen L (2009). Myrcene as a natural base chemical in sustainable chemistry: a critical review — review. ChemSusChem. https://pubmed.ncbi.nlm.nih.gov/20013989/
15. Surendran S, Qassadi F, Surendran G, et al. (2021). Myrcene-What Are the Potential Health Benefits of This Flavouring and Aroma Agent? — review. Front Nutr. https://pubmed.ncbi.nlm.nih.gov/34350208/
16. Schilmiller AL, Schauvinhold I, Larson M, et al. (2009). Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate — plant biochemistry and genetics. Proc Natl Acad Sci U S A. https://pubmed.ncbi.nlm.nih.gov/19487664/
17. Bonaccorsi I, Sciarrone D, Schipilliti L, et al. (2011). Composition of Egyptian nerolì oil — GC-MS and chiral composition study. Nat Prod Commun. https://pubmed.ncbi.nlm.nih.gov/21834247/
18. Hesse A, Zeitschel O (1902). Ueber Orangenblüthenöl II — chemical isolation. Journal für Praktische Chemie. https://doi.org/10.1002/prac.19020660130

View all 18 references▾