Cornflower (Centaurea cyanus) Herbal Monograph

What Is Cornflower?

Cornflower is an annual wildflower in the daisy family, known for its vivid blue flower heads. It was once a common weed of European grain fields, which gave it its name, and it is now widely grown as an ornamental and an edible flower ^{18,19Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

The plant is native to southern Europe and has spread widely as a garden escape, including across North America ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. In the wild, its cornfield populations have declined sharply across Europe ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

The flower’s blue colour comes from protocyanin, a pigment complex built from a cyanidin-based anthocyanin, a flavone and metal ions ^{15Reference 15Takeda et al. · 2005Components of protocyanin, a blue pigment from the blue flowers of Centaurea cyanus — structural studyView study →}. Research on the flowers has looked at anti-inflammatory and antioxidant activity, almost entirely in animals and the laboratory ^{1,2Reference 1Garbacki et al. · 1999AnimalAnti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivoView study →Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →}.

Its best-known medicinal use was for the eyes. A cooled infusion of the flowers was used as a compress for eye inflammation, and in French the plant is called casse-lunettes, “spectacle-breaker” ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}.

How Is Cornflower Used?

Cornflower is used as the dried blue florets, most often as a colourful ingredient in tea blends and as an edible garnish ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

Infusion — a light tea of the dried flowers.
Eye compress — a cooled, well-strained infusion, prepared fresh and used the same day.
Food — petals in salads, desserts and tea blends for colour, and as a natural dye.

Traditional Uses

European Folk Medicine

The drug is the blue floret, gathered at full flower and dried, and the usual preparation is an infusion.

Cornflower’s main traditional use was for the eyes. Poultices and infusions of the flowers were used for eye inflammation from the eighteenth century, and this remained its most common use until the middle of the twentieth century ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}. Renaissance herbals valued it for cleansing the eyes and wounds, and it has been used as a folk remedy for eye diseases in Belarus, Kosovo, Bosnia and Herzegovina, Italy, Spain and Armenia ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

In Hungary the flowers were also taken as an infusion for their diuretic effect and for jaundice, and used as a throat rinse ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}. Cornflower was among the most popular medicinal plants gathered from the wild in Hungary until the 1960s ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

The flowers were also used as a bitter tonic for weak digestion and appetite, and applied for their astringency to mouth ulcers and small wounds.

Food and Colour

The petals go into salads, desserts and tea blends for their colour and mild flavour, and they are a natural dye. In Hungarian tradition the flowers were added to tea blends to improve their colour ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}. Other records describe the flowers being made into wine and beer with sugar, and used to colour vinegar ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

Indications

Eye inflammation and irritated eyes [flower infusion, as a cooled compress; European folk medicine]
Fluid retention [flower infusion; Hungarian folk medicine]
Jaundice [flower; Hungarian folk medicine]
Weak digestion and poor appetite [flower infusion; European folk medicine]
Mouth ulcers and sore throat [flower infusion, as a rinse; European folk medicine]
Minor wounds [flower; European folk medicine]

Botany

Cornflower is an annual in the daisy family, Asteraceae, growing 20–100 cm tall ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. It usually has a single upright stem, branching near the top and covered in loose, woolly hairs ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}.

The leaves are grey and woolly. The lower leaves are narrow and lance-shaped, 3–10 cm long, with smooth edges or a few narrow lobes, and the upper leaves are narrow and usually entire ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}.

Each flower head holds 25–35 florets. They are usually blue, but can be white to purple ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. The outer florets are sterile and enlarged, 20–25 mm long, and spread like rays around the smaller fertile florets in the centre ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}.

The bracts below the head are green, with fringed edges that are white to dark brown or black ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. The seeds are straw-coloured or pale blue, 4–5 mm long, and topped with stiff bristles ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. It flowers from late spring through summer ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}.

Distribution

Cornflower is native to southern Europe ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. It became a weed of grain fields and was once common in many European countries, but it has declined and become threatened almost everywhere because of the intensification of farming ^{19Reference 19Pinke et al. · 2022ReviewIconic arable weeds: the significance of corn poppy (Papaver rhoeas), cornflower (Centaurea cyanus), and field larkspur (Delphinium consolida) in Hungarian ethnobotanical and cultural heritage — ethnobotanical reviewView study →}.

It is commonly grown as a garden ornamental, its seeds are often included in wildflower mixes, and it naturalises readily ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}. In North America it grows in grasslands, woodlands, roadsides and other disturbed ground from 50 to 2,400 m, in nearly every US state and Canadian province ^{18Reference 18Keil et al. · 2006Centaurea cyanus Linnaeus — species description, habitat and distribution — floraView study →}.

Sourcing: the flowers in trade come from cultivated plants, grown from seed for the dried-flower and tea-blend market. The decline of wild cornflower has no bearing on supply. Conservation of the wild plant depends on field margins and reduced herbicide use.

Growing Conditions

Cultivation snapshot for Cornflower

LifeannualZoneUSDA 2–11

Hardy cool-season annual (grown across roughly USDA zones 2–11); full sun; easy from seed in open ground.

Grow it yourself

Farm Wiki is our cultivation-focused sister site, also run by Justin Cooke.

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Phytochemistry

The blue colour of the flower comes from protocyanin, a metal complex pigment. It is built from the anthocyanin centaurocyanin (a cyanidin glycoside, cyanidin 3-O-(6-O-succinylglucoside)-5-O-glucoside), an apigenin-derived flavone glycoside, and iron, magnesium and calcium ions ^{15Reference 15Takeda et al. · 2005Components of protocyanin, a blue pigment from the blue flowers of Centaurea cyanus — structural studyView study →}.

An aqueous extract of the petals contained chlorogenic, caffeic, ferulic and p-coumaric acids, isoquercitrin and coumarin as its major compounds ^{2Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →}. The flavonoids luteolin and quercetin are also reported.

The flowers contain the sesquiterpene lactone 13-O-acetylsolstitialin A, which is cytotoxic to breast-cancer cells in vitro ^{10Reference 10Keyvanloo Shahrestanaki et al. · 2019In vitroCentaurea cyanus-extracted 13-O-acetylsolstitialin A decreases Bax/Bcl-2 ratio and cyclin D1/Cdk-4 expression to induce apoptosis and cell-cycle arrest in MCF-7 and MDA-MB-231 breast cancer cell lines — in vitroView study →}. Cnicin, chamazulene, limonene and α-pinene are also listed for the plant.

The seeds contain indole alkaloids, moschamine and its relatives cis-moschamine, centcyamine and cis-centcyamine ^{16Reference 16Sarker et al. · 2001Indole alkaloids from the seeds of Centaurea cyanus (Asteraceae) — moschamine, centcyamine; brine-shrimp toxicity assayView study →}. Moschamine inhibits cyclooxygenase enzymes in vitro ^{9Reference 9Park et al. · 2012In vitroSynthesis, biological activities and bioavailability of moschamine, a safflomide-type phenylpropenoic acid amide found in Centaurea cyanus — in vitro (COX inhibition, 5-HT1 binding)View study →}.

Herbicide-resistant cornflower plants had more phenolic compounds and flavonoids in their flowers than susceptible plants ^{7Reference 7Gawlik-Dziki et al. · 2023In vitroHerbicide resistance status impacts the profile of non-anthocyanin polyphenolics and some phytomedical properties of edible cornflower flowers — in vitroView study →}.

Constituent Summary

Reported from the flower heads unless noted. † marks the cyanidin-based anthocyanins of protocyanin, the blue pigment.

Grouped by class · 12 compounds

Anthocyanins2 compoundsno data

AnthocyaninsAnthocyanins †No data

AnthocyaninsCyanidinNo data

Flavonoids3 compoundsno data

FlavonoidsApigeninNo data

FlavonoidsLuteolinNo data

FlavonoidsQuercetinNo data

Phenolic Acids2 compoundsno data

Phenolic AcidsCaffeic acidNo data

Phenolic AcidsChlorogenic acidNo data

Phenylpropenoic Acid Amides1 compound1 with data

Phenylpropenoic Acid AmidesMoschamineNo Data (seed)

Sesquiterpene Lactones1 compoundno data

Sesquiterpene LactonesCnicinNo data

Sesquiterpenes1 compoundno data

SesquiterpenesChamazuleneNo data

Monoterpenes2 compoundsno data

MonoterpenesLimoneneNo data

Monoterpenesα-PineneNo data

Pharmacology & Research

A few dozen papers have been published on cornflower, almost all laboratory and animal work. No clinical trial has tested it.

Polysaccharides from the flower heads reduced inflammation in animal models and interfered with the complement system, in a study that noted the plant’s use in European phytotherapy for minor eye inflammation ^{1Reference 1Garbacki et al. · 1999AnimalAnti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivoView study →}. Antioxidant activity is the most often measured property, and several groups rate it as low to moderate compared with other edible flowers ^{2,3,4,6Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →Reference 4Sharonova et al. · 2021In vitroComparative assessment of the phytochemical composition and biological activity of extracts of Centaurea cyanus, C. jacea and C. scabiosa — in vitroView study →Reference 6Król et al. · 2025In vitroYogurt with cornflower (Centaurea cyanus L.) petals as a source of antioxidant compounds and dietary fibre — in vitro / food matrixView study →}.

A 2024 study found that a water extract of the flowers protected muscle from steroid-induced wasting in cells and mice ^{8Reference 8Nguyen et al. · 2024In vitroCornflower extract and its active components alleviate dexamethasone-induced muscle wasting by targeting cannabinoid receptors and modulating gut microbiota — in vitro and mouse in vivoView study →}.

What the Evidence Supports

Best-supported: anti-inflammatory activity of the flower-head polysaccharide fraction in animal oedema models ^{1Reference 1Garbacki et al. · 1999AnimalAnti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivoView study →}; broadly consistent but modest in vitro antioxidant capacity ^{2,3,6Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →Reference 6Król et al. · 2025In vitroYogurt with cornflower (Centaurea cyanus L.) petals as a source of antioxidant compounds and dietary fibre — in vitro / food matrixView study →}.
Emerging, worth watching: a 2024 in vitro + mouse study in which cornflower water extract blunted steroid-induced muscle wasting via cannabinoid-receptor signalling ^{8Reference 8Nguyen et al. · 2024In vitroCornflower extract and its active components alleviate dexamethasone-induced muscle wasting by targeting cannabinoid receptors and modulating gut microbiota — in vitro and mouse in vivoView study →}.
Mechanistically thin: the antiproliferative and antihypertensive findings rest on single cell-line or in vitro assays ^{2,10Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →Reference 10Keyvanloo Shahrestanaki et al. · 2019In vitroCentaurea cyanus-extracted 13-O-acetylsolstitialin A decreases Bax/Bcl-2 ratio and cyclin D1/Cdk-4 expression to induce apoptosis and cell-cycle arrest in MCF-7 and MDA-MB-231 breast cancer cell lines — in vitroView study →}; antimicrobial activity is inconsistent and often rated low ^{3,4Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →Reference 4Sharonova et al. · 2021In vitroComparative assessment of the phytochemical composition and biological activity of extracts of Centaurea cyanus, C. jacea and C. scabiosa — in vitroView study →}.
The caveat: no human data, no standardised dose, and phytochemistry that varies with cultivar and growing conditions ^{4,7Reference 4Sharonova et al. · 2021In vitroComparative assessment of the phytochemical composition and biological activity of extracts of Centaurea cyanus, C. jacea and C. scabiosa — in vitroView study →Reference 7Gawlik-Dziki et al. · 2023In vitroHerbicide resistance status impacts the profile of non-anthocyanin polyphenolics and some phytomedical properties of edible cornflower flowers — in vitroView study →}.

Results depend on the preparation. The anti-inflammatory effect came from a purified polysaccharide fraction and the COX effect from a seed compound, and the plant’s chemistry shifts with cultivar and growing conditions ^{1,7,9Reference 1Garbacki et al. · 1999AnimalAnti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivoView study →Reference 7Gawlik-Dziki et al. · 2023In vitroHerbicide resistance status impacts the profile of non-anthocyanin polyphenolics and some phytomedical properties of edible cornflower flowers — in vitroView study →Reference 9Park et al. · 2012In vitroSynthesis, biological activities and bioavailability of moschamine, a safflomide-type phenylpropenoic acid amide found in Centaurea cyanus — in vitro (COX inhibition, 5-HT1 binding)View study →}.

Evidence by IndicationStrength of support

Anti-InflammatoryPromising

58%

AntioxidantPromising

55%

Anti-Sarcopenic (Muscle-Wasting)Promising

46%

AntimicrobialShaky

42%

Skin-Protective (Wound / UV)Shaky

38%

Antiproliferative (Anticancer)Shaky

30%

AntihypertensiveShaky

24%

1. Anti-Inflammatory

Polysaccharides isolated from the flower heads inhibited carrageenan-, zymosan- and croton-oil-induced oedema in animal models and interfered with the complement system. The active fraction was made up mainly of galacturonic acid, arabinose, glucose, rhamnose and galactose ^{1Reference 1Garbacki et al. · 1999AnimalAnti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivoView study →}.

Moschamine, an amide from the seeds, inhibited both cyclooxygenase enzymes in vitro, COX-I by 58% and COX-II by 54% at 0.1 µmol/L ^{9Reference 9Park et al. · 2012In vitroSynthesis, biological activities and bioavailability of moschamine, a safflomide-type phenylpropenoic acid amide found in Centaurea cyanus — in vitro (COX inhibition, 5-HT1 binding)View study →}.

Gap: the animal effect belongs to an isolated polysaccharide fraction, and no study has tested a simple flower infusion used as an eye compress.

2. Antioxidant

Antioxidant capacity is cornflower’s most-measured property, assayed by DPPH, FRAP, ABTS and lipid-peroxidation methods across petal extracts, infusions and foods made with the petals ^{2,3,6Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →Reference 6Król et al. · 2025In vitroYogurt with cornflower (Centaurea cyanus L.) petals as a source of antioxidant compounds and dietary fibre — in vitro / food matrixView study →}.

The activity is real but modest. A comparison of three Centaurea species found low antioxidant activity in a cornflower flower extract ^{4Reference 4Sharonova et al. · 2021In vitroComparative assessment of the phytochemical composition and biological activity of extracts of Centaurea cyanus, C. jacea and C. scabiosa — in vitroView study →}, and a study of four edible flowers rated their activity moderate overall, with rose the strongest ^{3Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →}.

Herbicide-resistant cornflower plants had higher phenolic content and antioxidant activity than susceptible ones ^{7Reference 7Gawlik-Dziki et al. · 2023In vitroHerbicide resistance status impacts the profile of non-anthocyanin polyphenolics and some phytomedical properties of edible cornflower flowers — in vitroView study →}. Adding freeze-dried petals to yogurt raised its antioxidant activity ^{6Reference 6Król et al. · 2025In vitroYogurt with cornflower (Centaurea cyanus L.) petals as a source of antioxidant compounds and dietary fibre — in vitro / food matrixView study →}.

All of this is from chemical assays in the laboratory, with no measurement in a living system.

3. Anti-Sarcopenic (Muscle-Wasting)

A 2024 study tested a cornflower water extract against muscle wasting caused by the steroid dexamethasone, in C2C12 muscle cells and in mice ^{8Reference 8Nguyen et al. · 2024In vitroCornflower extract and its active components alleviate dexamethasone-induced muscle wasting by targeting cannabinoid receptors and modulating gut microbiota — in vitro and mouse in vivoView study →}.

In cells, the extract and compounds isolated from it reduced oxidative stress, promoted muscle-fibre growth and raised ATP production. In mice, it improved grip strength and exercise performance and shifted muscle gene expression toward protein building. Docking pointed to cannabinoid receptors: the constituent graveobioside A inhibited CB1 and raised CB2. The extract also increased the diversity of gut bacteria ^{8Reference 8Nguyen et al. · 2024In vitroCornflower extract and its active components alleviate dexamethasone-induced muscle wasting by targeting cannabinoid receptors and modulating gut microbiota — in vitro and mouse in vivoView study →}.

Gap: the model was drug-induced muscle wasting, not age-related sarcopenia. One research group, one animal study, no replication.

4. Antimicrobial

A comparison of three Centaurea species found low antimicrobial activity in an ethanol extract of cornflower flowers; the strongest activity was in C. scabiosa ^{4Reference 4Sharonova et al. · 2021In vitroComparative assessment of the phytochemical composition and biological activity of extracts of Centaurea cyanus, C. jacea and C. scabiosa — in vitroView study →}. A study of four edible flowers found moderate antibacterial activity overall ^{3Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →}.

A cornflower extract loaded into a PVA wound-dressing hydrogel gave a Staphylococcus aureus inhibition zone of 16.9 mm, compared with 15.8 mm for ampicillin ^{11Reference 11Abahuni Ucar et al. · 2025In vitroInvestigation of PVA matrix hydrogel loaded with Centaurea cyanus extract for wound-dressing applications — in vitroView study →}.

Cornflower honey also has antibacterial activity, which comes from its hydrogen peroxide content. Used on cows’ hooves with digital dermatitis, it sped healing compared with no treatment ^{13Reference 13Oelschlaegel et al. · 2012In vitroFloral markers of cornflower (Centaurea cyanus) honey and its peroxide antibacterial activity — in vitroView study →}.

The results vary between studies and preparations, and all are in vitro except the honey study.

5. Skin-Protective (Wound / UV)

Polyphenols from a blend of edible-flower wastes that included cornflower boosted the antioxidant activity of a snail-mucus formulation. The combination protected skin cells exposed to UVB light and reduced reactive oxygen species and lipid peroxidation ^{12Reference 12Vanella et al. · 2023In vitroStandardized extract from wastes of edible flowers and snail mucus ameliorate ultraviolet B-induced damage in keratinocytes — in vitroView study →}.

In a separate study, a cornflower extract released caffeoylquinic acids and kaempferol from a PVA hydrogel. It was not toxic to skin fibroblasts and increased their growth by 19% ^{11Reference 11Abahuni Ucar et al. · 2025In vitroInvestigation of PVA matrix hydrogel loaded with Centaurea cyanus extract for wound-dressing applications — in vitroView study →}.

Gap: both are laboratory tests of formulations, with no wound-healing or sun-protection data in living skin.

6. Antiproliferative (Anticancer)

13-O-acetylsolstitialin A, a sesquiterpene lactone isolated from cornflower, was cytotoxic to MCF-7 and MDA-MB-231 breast-cancer cells. It shifted the balance of Bax and Bcl-2 toward cell death, lowered cyclin D1 and Cdk-4, and arrested the cell cycle ^{10Reference 10Keyvanloo Shahrestanaki et al. · 2019In vitroCentaurea cyanus-extracted 13-O-acetylsolstitialin A decreases Bax/Bcl-2 ratio and cyclin D1/Cdk-4 expression to induce apoptosis and cell-cycle arrest in MCF-7 and MDA-MB-231 breast cancer cell lines — in vitroView study →}.

A petal water extract, by contrast, showed low cytotoxicity across the cell lines tested ^{2Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →}, and an edible-flower screen found the strongest antiproliferative activity in dahlia and rose ^{3Reference 3Pires et al. · 2018In vitroEdible flowers as sources of phenolic compounds with bioactive potential — in vitro comparative studyView study →}.

Gap: isolated-compound cell-line data only.

7. Antihypertensive

An optimised water extract of cornflower petals showed antihypertensive activity in a laboratory assay, alongside antioxidant and anti-haemolytic effects ^{2Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →}.

Gap: a single in-vitro assay, with no animal or human follow-up.

Mechanisms

Polysaccharides from the flower heads reduce oedema and interfere with the complement system in animal models ^{1Reference 1Garbacki et al. · 1999AnimalAnti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivoView study →}. Being water-soluble, they are extracted by an infusion.

The flavonoids and phenolic acids of the flower, and the cyanidin-based anthocyanins that make it blue, have been studied for antioxidant activity ^{2,15Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →Reference 15Takeda et al. · 2005Components of protocyanin, a blue pigment from the blue flowers of Centaurea cyanus — structural studyView study →}. The seed amide moschamine inhibits cyclooxygenase enzymes and binds serotonin 5-HT1 receptors in vitro ^{9Reference 9Park et al. · 2012In vitroSynthesis, biological activities and bioavailability of moschamine, a safflomide-type phenylpropenoic acid amide found in Centaurea cyanus — in vitro (COX inhibition, 5-HT1 binding)View study →}.

Mechanism	Drives	Key compounds
Complement interference; edema suppression	anti-inflammatory (eyewash use)	polysaccharides (pectic — galacturonic acid / arabinose / rhamnose)
COX-I / COX-II inhibition; 5-HT1 binding	anti-inflammatory	moschamine
Radical scavenging; NF-κB / COX modulation	antioxidantanti-inflammatory	apigenin, luteolin, quercetin
Metal-chelating radical scavenging	antioxidantpigment/marker	cyanidin glycosides (protocyanin complex)
ROS reduction; keratinocyte protection	antioxidantskin-protective	caffeic acid, chlorogenic acid
Bax/Bcl-2 shift, cell-cycle arrest; bitter tonic	antiproliferative (in vitro)	13-O-acetylsolstitialin A, cnicin

Clinical Trials

No registered clinical trials of Centaurea cyanus were identified. A ClinicalTrials.gov search for “Centaurea cyanus” and “cornflower” returned no studies; the count below reflects the published laboratory and animal literature.

Completed	Planned	Terminated	Preclinical
0	0	0	~25(phytochemical + in vitro, a few animal)

Last checked: July 2026.

Dosage

Cornflower is used in culinary amounts: a scatter of dried petals in a tea blend, salad or dessert.

For an eye compress, a weak infusion of the flowers is cooled, strained thoroughly and used the same day.

Safety & Pregnancy

Cornflower is a low-risk edible flower with no reported toxicity at culinary or tea amounts. The main caution is allergy in people sensitive to the daisy family.

Safety at a Glance

Low / no toxicityDaisy-family allergy

Low-risk edible flower. No reported toxicity at culinary or tea amounts.
Daisy-family allergy. It may cross-react in people sensitive to the daisy family, such as ragweed, chamomile and marigold.
Eye use. A home infusion is not sterile. Prepare it fresh, strain it well and use it the same day.
Interactions not studied. There are no drug-interaction studies.

Full Safety & Interactions Detail

Toxicity. Cornflower has no reported toxicity at culinary or tea amounts. A petal water extract showed low toxicity to cells in the laboratory ^{2Reference 2Escher et al. · 2018In vitroChemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract — in vitroView study →}, and the seed alkaloids showed only general low-level toxicity in a brine-shrimp test ^{16Reference 16Sarker et al. · 2001Indole alkaloids from the seeds of Centaurea cyanus (Asteraceae) — moschamine, centcyamine; brine-shrimp toxicity assayView study →}.

Allergy. People sensitive to the daisy family (Asteraceae), such as to ragweed, chamomile or marigold, may react to cornflower.

Eye use. Dried herbs can carry bacteria. In a survey of 51 dried-herb samples from six plants, including cornflower, grown on small Italian farms, 29.4% exceeded the limit for mesophilic bacteria, though the authors judged overall quality good ^{17Reference 17Vitullo et al. · 2011Microbiological and toxicological quality of dried herbs including Centaurea cyanus — analytical surveyView study →}. Any infusion used on the eyes should be freshly made, well strained and used the same day.

Serotonin receptors. The seed compound moschamine binds serotonin 5-HT1 receptors in cells ^{9Reference 9Park et al. · 2012In vitroSynthesis, biological activities and bioavailability of moschamine, a safflomide-type phenylpropenoic acid amide found in Centaurea cyanus — in vitro (COX inhibition, 5-HT1 binding)View study →}. No effect at tea or garnish amounts has been shown.

Interactions. No pharmacokinetic or drug-interaction study of cornflower has been done.

Pregnancy & Lactation

Caution in pregnancy Caution while breastfeeding

Caution. Cornflower has not been studied in pregnancy or breastfeeding. Keep to culinary amounts of the petals and avoid concentrated or medicinal preparations.

References

Garbacki, N., Gloaguen, V., Damas, J., Bodart, P., Tits, M., & Angenot, L. (1999). Anti-inflammatory and immunological effects of Centaurea cyanus flower-heads — animal model / in vivo. Journal of Ethnopharmacology, 68(1–3), 235–241. https://pubmed.ncbi.nlm.nih.gov/10624883/
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