Cyanidin-3-Glucoside

Cyanidin-3-Glucoside at a Glance

Cyanidin-3-glucoside — usually abbreviated C3G, and also called kuromanin or chrysanthemin — is the 3-O-glucoside of cyanidin: the parent anthocyanidin with a single glucose sugar attached at its 3-position. It is the red-to-purple pigment of black rice, blackberries, black raspberries, elderberry, black beans and purple corn, and it is widely regarded as the single most abundant anthocyanin in the human diet ^{6,12Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →Reference 12Wang LS · 2008Anthocyanins and their role in cancer preventionView study →}.

Unlike its unstable free aglycone, C3G is the stable, studied form in which cyanidin actually occurs and is eaten — so most “cyanidin” research is really about this molecule or about anthocyanin mixtures. Its preclinical profile is broad and coherent: metabolic (anti-obesity, glycaemic), cardiovascular (anti-atherosclerotic, endothelial), anti-inflammatory and antioxidant effects, running mostly through Nrf2, NF-κB and cholesterol-transporter pathways rather than one target ^{5,6,7Reference 5Tsuda T et al. · 2003AnimalDietary cyanidin 3-O-β-D-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in miceView study →Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →Reference 7Wang Y et al. · 2012AnimalSupplementation with cyanidin-3-O-β-glucoside protects against hypercholesterolemia-mediated endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E-deficient miceView study →}.

The load-bearing caveat is bioavailability. C3G is absorbed only in trace amounts (well under 1% survives intact), and it is extensively degraded in the gut to phenolic acids — chiefly protocatechuic acid — so a large share of the activity credited to C3G may actually be its metabolites’ ^{1,2Reference 1Czank C et al. · 2013Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a ¹³C-tracer studyView study →Reference 2Vitaglione P et al. · 2007Protocatechuic acid is the major human metabolite of cyanidin-glucosidesView study →}. Its toxicity is low: it is a food-grade dietary pigment eaten in quantity, and the human trials that exist use anthocyanin mixtures, not the isolate.

The Most Abundant Dietary Anthocyanin

Two words that look alike are worth separating first. An anthocyanidin is the sugar-free pigment core — here, cyanidin. An anthocyanin is that core with one or more sugars attached; C3G is cyanidin plus a single glucose at the 3-position. In plants the pigments occur almost entirely as anthocyanins (glycosides), not as free aglycones, because the sugar makes the molecule far more stable and water-soluble — which is exactly why C3G, and not free cyanidin, is what colours food and what the body encounters.

Among all dietary anthocyanins, C3G is the most common: it is the dominant or co-dominant pigment across a remarkable range of pigmented staples — black rice, blackberry, black raspberry, elderberry, black beans, purple corn, cherries and red cabbage — and total dietary anthocyanin intake in Western diets is on the order of ~200 mg/day, more than any other flavonoid class, with cyanidin glycosides prominent in that total ^{6,12Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →Reference 12Wang LS · 2008Anthocyanins and their role in cancer preventionView study →}.

The other defining trait is pH-dependent colour and stability. In acidic conditions (roughly pH < 3) C3G exists as the deeply coloured red flavylium cation; as pH rises toward neutral it loses colour, shifting through the colourless carbinol (pseudobase) and pale chalcone forms, and toward alkaline pH it becomes blue-purple quinoidal bases. The practical consequences are large: C3G is vividly coloured and reasonably stable in an acidic food or the stomach, but chemically labile at the near-neutral pH of blood and tissue — a fact that runs straight into its poor bioavailability (below). Glycosylation makes C3G more stable than the free aglycone, but it does not make it robust at body pH.

Bioavailability & the Protocatechuic Acid Question

This is the most important section on the page. Anthocyanins are notoriously poorly bioavailable, and C3G is the molecule where that has been measured most precisely. In the definitive ¹³C-labelled human tracer study — 500 mg of isotopically labelled C3G given orally — the compound’s relative bioavailability was around 12% by total label recovery, but only a trace of intact C3G appeared in serum; the overwhelming majority of the recovered label was downstream metabolites, and the true elimination half-life was far longer than the parent-compound measurements had suggested ^{1Reference 1Czank C et al. · 2013Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a ¹³C-tracer studyView study →}. Human pharmacokinetic work confirms the pattern: intact anthocyanins circulate at only nanomolar concentrations, while phenolic-acid metabolites dominate systemic exposure ^{3Reference 3de Ferrars RM et al. · 2014The pharmacokinetics of anthocyanins and their metabolites in humansView study →}.

The single most important metabolite is protocatechuic acid (PCA). In a human study of cyanidin-glucosides from blood-orange juice, PCA accounted for ~73% of the ingested dose, and serum PCA vastly exceeded the intact anthocyanin ^{2Reference 2Vitaglione P et al. · 2007Protocatechuic acid is the major human metabolite of cyanidin-glucosidesView study →}. This reframes the whole molecule: when C3G “works” in a person, the active species reaching the tissues is largely not C3G but PCA and other ring-fission phenolics generated by gut microbiota and host metabolism. Preclinical work makes the point directly — in apolipoprotein-E-deficient mice, C3G reduced monocyte infiltration “with the aid of its metabolite protocatechuic acid,” explicitly crediting the metabolite as part of the mechanism ^{8Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →}.

The honest reading: the isolate’s activity is partly its metabolites’. Any C3G health claim has to survive the fact that very little of the parent molecule ever reaches the bloodstream intact, and that its most abundant human metabolite is a separate, well-characterised phenolic acid with its own pharmacology.

What It's Used For

C3G’s preclinical profile is genuine and mechanistically coherent, but two disciplines govern how to read it: almost all of the C3G-specific efficacy data are rodent or in-vitro, and the human evidence is for anthocyanin mixtures, not the isolate ^{6,9Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →Reference 9Zhu Y et al. · 2011Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individualsView study →}. The bioavailability caveat above sits under every row.

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. C3G-specific human efficacy data are essentially absent (the human trials use mixtures), so scores stay modest by design. Each application links to its write-up.

01Metabolic & Anti-ObesityPromising46%Landmark C3G-rich purple-corn rodent work + review; human data are mixtures ^{5,6,11Reference 5Tsuda T et al. · 2003AnimalDietary cyanidin 3-O-β-D-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in miceView study →Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}

02Cardiovascular & EndothelialShaky44%C3G apoE-mouse atherosclerosis + human anthocyanin-mixture RCTs ^{7,8,9,11Reference 7Wang Y et al. · 2012AnimalSupplementation with cyanidin-3-O-β-glucoside protects against hypercholesterolemia-mediated endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E-deficient miceView study →Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →Reference 9Zhu Y et al. · 2011Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individualsView study →Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}

03Anti-InflammatoryShaky38%NF-κB mechanism + a purified-anthocyanin human RCT (mixture) ^{8,10Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →Reference 10Zhu Y et al. · 2013RCTAnti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trialView study →}

04AntioxidantShaky34%Cell-free/LDL-oxidation assays; dose- and timing-dependent ^{4,13Reference 4Kähkönen MP · 2003Antioxidant activity of anthocyanins and their aglyconsView study →Reference 13Abuja PM et al. · 1998Antioxidant and prooxidant activities of elderberry (Sambucus nigra) extract in low-density lipoprotein oxidationView study →}

05AnticancerShaky22%Cell/animal, anthocyanin mixtures; poor human translation ^{12Reference 12Wang LS · 2008Anthocyanins and their role in cancer preventionView study →}

06AntigenotoxicShaky20%Whole camu-camu juice in mice, not the isolate ^{16Reference 16da Silva FC et al. · 2019AnimalAntigenotoxic and antimutagenic effects of Myrciaria dubia juice in mice submitted to ethanol 28-day treatmentView study →}

Mechanisms

The load-bearing line is the last one: because so little C3G is absorbed intact, several of the effects above may be delivered in vivo by its metabolites — chiefly protocatechuic acid — rather than by C3G itself ^{1,2,8Reference 1Czank C et al. · 2013Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a ¹³C-tracer studyView study →Reference 2Vitaglione P et al. · 2007Protocatechuic acid is the major human metabolite of cyanidin-glucosidesView study →Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →}.

Clinical Trials

There are no controlled efficacy trials of isolated C3G. The human evidence is a small set of trials of purified anthocyanin mixtures (the bilberry/blackcurrant preparation Medox, ~320 mg/day), in which C3G is one of several anthocyanins: these improved endothelial function ^{9Reference 9Zhu Y et al. · 2011Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individualsView study →}, inflammatory markers ^{10Reference 10Zhu Y et al. · 2013RCTAnti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trialView study →} and the LDL/HDL profile ^{11Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}. C3G-specific efficacy data are preclinical.

Last checked: July 2026.

How Cyanidin-3-Glucoside Works

The throughline across C3G’s effects is redox and inflammatory signalling, reached through several parallel routes — with the persistent asterisk that the molecule reaching tissue is often its metabolite.

Nrf2 & Antioxidant Defence

C3G activates the Nrf2/antioxidant-response-element axis, raising endogenous antioxidant-enzyme expression and shifting lipid handling toward fatty-acid oxidation — part of its metabolic and antioxidant profile ^{6Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →}.

NF-κB & Inflammation

C3G suppresses NF-κB-driven transcription, lowering pro-inflammatory mediators (TNF-α, IL-1β) and vascular adhesion molecules (VCAM-1) — the mechanism behind both its anti-inflammatory and its anti-atherosclerotic signals ^{7,8,10Reference 7Wang Y et al. · 2012AnimalSupplementation with cyanidin-3-O-β-glucoside protects against hypercholesterolemia-mediated endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E-deficient miceView study →Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →Reference 10Zhu Y et al. · 2013RCTAnti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trialView study →}.

Cholesterol Efflux & Lipid Metabolism

In vascular cells C3G upregulates the ABCA1 and ABCG1 cholesterol transporters, promoting efflux of cholesterol and 7-ketocholesterol ^{7Reference 7Wang Y et al. · 2012AnimalSupplementation with cyanidin-3-O-β-glucoside protects against hypercholesterolemia-mediated endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E-deficient miceView study →}; systemically, the human mixture data point to CETP inhibition improving the LDL/HDL balance ^{11Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}, while AMPK-linked effects reduce lipogenesis ^{6Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →}.

The Metabolite Contribution

Because intact C3G barely reaches the circulation, its gut-derived phenolic-acid metabolites — above all protocatechuic acid — are part of the working mechanism, explicitly credited in the anti-atherosclerotic monocyte study ^{8Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →}. Any mechanistic read of C3G has to hold the parent and its metabolites together.

A Unifying Interpretation

Most of C3G’s repertoire collapses into one economical picture: an anti-inflammatory, redox-modulating, lipid-favourable action built from Nrf2 activation, NF-κB suppression and cholesterol-transporter upregulation, which together explain the metabolic, cardiovascular and anti-inflammatory signals without a distinct receptor for each. Layered under all of it is the pharmacokinetic asterisk — minimal absorption and extensive conversion to protocatechuic acid — which means the in-vivo actor is a blend of parent molecule and metabolites. The evidence base is largely preclinical, and the human data are mixtures, so the interpretation is “coherent and promising,” not “clinically established.”

Isolate vs. Plant Studies

C3G sits in an unusual middle. The mechanistic and rodent efficacy work is genuinely the isolated molecule (or C3G-rich fractions) — the purple-corn anti-obesity study ^{5Reference 5Tsuda T et al. · 2003AnimalDietary cyanidin 3-O-β-D-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in miceView study →}, the apoE-mouse atherosclerosis and monocyte studies ^{7,8Reference 7Wang Y et al. · 2012AnimalSupplementation with cyanidin-3-O-β-glucoside protects against hypercholesterolemia-mediated endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E-deficient miceView study →Reference 8Wang D et al. · 2011AnimalCyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient miceView study →}, and the C3G metabolic reviews ^{6Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →} all test C3G directly, which is a real strength. But the human efficacy evidence is a mixture: the endothelial, inflammatory and lipid RCTs used a purified bilberry/blackcurrant anthocyanin preparation in which C3G is one of several pigments (delphinidin glycosides among them), not isolated C3G ^{9,10,11Reference 9Zhu Y et al. · 2011Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individualsView study →Reference 10Zhu Y et al. · 2013RCTAnti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trialView study →Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}. And in the whole-food setting — camu-camu, elderberry — C3G is the principal anthocyanin among many co-acting constituents (vitamin C, ellagitannins, other anthocyanins, flavonols) ^{14,15,16Reference 14Zanatta CF et al. · 2005Determination of anthocyanins from camu-camu (Myrciaria dubia) by HPLC-PDA, HPLC-MS, and NMRView study →Reference 15Mikulic-Petkovsek M et al. · 2014Investigation of anthocyanin profile of four elderberry species and interspecific hybridsView study →Reference 16da Silva FC et al. · 2019AnimalAntigenotoxic and antimutagenic effects of Myrciaria dubia juice in mice submitted to ethanol 28-day treatmentView study →}. The correct framing: strong isolate/rodent mechanism + meaningful human anthocyanin-mixture evidence + no isolated-C3G human trials — and the caveat that even the “isolate” is largely delivered to tissue as its metabolites.

Its Role in Plants

C3G is produced through the flavonoid/anthocyanin biosynthetic pathway: the anthocyanidin cyanidin is formed from dihydroflavonol precursors (via leucoanthocyanidin and anthocyanidin synthase), then glucosylated at the 3-position by a UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) to give the stable, water-soluble glucoside that plants actually accumulate.

Its function is pigmentation — the red-to-purple colour of fruit skins, seed coats (black rice, black beans), flowers and autumn foliage — which serves pollinator and seed-disperser attraction, and it contributes to photoprotection and antioxidant stress defence, buffering the plant against UV and reactive oxygen. The glucoside form is favoured over the free aglycone precisely because the sugar confers the stability and solubility needed to store the pigment in the vacuole. These are plant-biology roles and should not be read as human pharmacology.

Prevalence in Nature

C3G is the most widespread anthocyanin in the plant kingdom and the human diet, occurring across many families as the dominant or co-dominant pigment of red, purple and black tissues ^{6,12Reference 6Oumeddour DZ et al. · 2024ReviewRecent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive reviewView study →Reference 12Wang LS · 2008Anthocyanins and their role in cancer preventionView study →}. It is the principal anthocyanin of black rice, and a major pigment of blackberry, black raspberry, cherry, red cabbage, black beans and purple corn. In the two source herbs here it is quantitatively important: it is the dominant anthocyanin of camu-camu (~88–90% of total anthocyanin) in the ripe fruit ^{14Reference 14Zanatta CF et al. · 2005Determination of anthocyanins from camu-camu (Myrciaria dubia) by HPLC-PDA, HPLC-MS, and NMRView study →}, and one of the two co-dominant berry anthocyanins of elder (with cyanidin-3-sambubioside), present at roughly 205–481 mg/100 g fresh fruit — a wide range driven by genotype, ripeness, species and drying method ^{15Reference 15Mikulic-Petkovsek M et al. · 2014Investigation of anthocyanin profile of four elderberry species and interspecific hybridsView study →}.

Concentrations vary enormously with plant part, cultivar, ripeness, growing conditions and processing, and because C3G is pH- and heat-labile, the amount in a food shifts with handling and storage. Where reported figures are unavailable or use different anthocyanin-equivalent bases, the numbers are best treated as comparative, not absolute.

Major Natural Sources

Source	Plant part	Reported C3G content
Elder (Sambucus nigra)	ripe berry	~205–481 mg/100 g fresh 15Reference 15Mikulic-Petkovsek M et al. · 2014Investigation of anthocyanin profile of four elderberry species and interspecific hybridsView study →
Camu-camu (Myrciaria dubia)	ripe fruit	~26–49 mg/100 g fresh (≈88–90% of total anthocyanin) 14Reference 14Zanatta CF et al. · 2005Determination of anthocyanins from camu-camu (Myrciaria dubia) by HPLC-PDA, HPLC-MS, and NMRView study →
Black rice (Oryza sativa)	bran / whole grain	the principal anthocyanin (variety-dependent)
Blackberry / black raspberry (Rubus spp.)	fruit	a dominant anthocyanin
Purple corn (Zea mays)	kernel / cob	C3G-rich pigment fraction 5Reference 5Tsuda T et al. · 2003AnimalDietary cyanidin 3-O-β-D-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in miceView study →

Figures are for the stated plant part and, for camu-camu and elder, are cited; the black-rice, Rubus and purple-corn entries are qualitative where a single comparable number is not established (a documented gap).

Other Reported Sources

C3G is also reported from:

• Black beans (Phaseolus vulgaris)
• Bilberry (Vaccinium myrtillus)
• Blackcurrant (Ribes nigrum)
• Red cabbage (Brassica oleracea)
• Cherries (Prunus spp.)
• Chokeberry (Aronia melanocarpa)
• Mulberry (Morus spp.)
• Red grape skins

In most of these it co-occurs with other anthocyanins — delphinidin, peonidin, malvidin, pelargonidin and petunidin glycosides — and with the related proanthocyanidins.

Discovery & Synthesis

C3G was characterised within the early-twentieth-century anthocyanin pigment chemistry pioneered by Richard Willstätter, Robert Robinson and their contemporaries, who worked out the flavylium structures of the plant pigments; the individual glucoside acquired the trivial names chrysanthemin (from Chrysanthemum) and kuromanin. An exact first-isolation date for C3G specifically is not well documented in the accessible literature.

Manufacture today is overwhelmingly by extraction, not synthesis. Anthocyanins are produced commercially as natural food colourants (the E163 class) from pigment-rich crops — black rice, purple corn, grape skin, elderberry, bilberry, black carrot and red cabbage — with C3G a major component of several of these extracts. Total chemical synthesis of anthocyanins is possible but difficult (the flavylium cation is reactive and the glycosidic and hydroxyl groups need protection), so purified C3G is sold mainly as an analytical reference standard rather than made synthetically at scale; when studies use “C3G,” it is typically isolated from a plant source.

Patents: not yet researched (future patent-loop pass).

Toxicity & Safety

C3G carries a low flag. It is a dietary pigment eaten in quantity in coloured fruits, grains, vegetables and flowers, used commercially as a food colourant (anthocyanin/E163 class), and generally regarded as safe at ordinary dietary levels with no significant toxicity from normal food intake. In human trials, purified anthocyanin mixtures at ~320 mg/day for up to 24 weeks were well tolerated ^{9,10,11Reference 9Zhu Y et al. · 2011Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individualsView study →Reference 10Zhu Y et al. · 2013RCTAnti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trialView study →Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}, and C3G’s very poor systemic bioavailability further limits any systemic-toxicity concern ^{1,3Reference 1Czank C et al. · 2013Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a ¹³C-tracer studyView study →Reference 3de Ferrars RM et al. · 2014The pharmacokinetics of anthocyanins and their metabolites in humansView study →}. The main nuances are chemical rather than clinical: like other polyphenols, C3G can turn pro-oxidant under some in-vitro conditions (high concentration, catalysing metals, late addition to an oxidation system) ^{13Reference 13Abuja PM et al. · 1998Antioxidant and prooxidant activities of elderberry (Sambucus nigra) extract in low-density lipoprotein oxidationView study →}, and its pH/heat lability means the “dose” in a food is not fixed. There are no established drug interactions for the isolate; theoretical additive antioxidant/anti-inflammatory effects from anthocyanin-rich intake are unconfirmed.

Reproductive note (prose only). No dedicated reproductive- or developmental-toxicity dataset exists for isolated C3G. As a common dietary anthocyanin it is consumed routinely in ordinary food, but pregnancy/lactation decisions belong to the herb or product page where intake is decided, not to this molecule page; no isolate-specific verdict is issued here.

Safety at a Glance

✅ Low / no toxicity

• A low-toxicity dietary pigment. Eaten in quantity in pigmented foods and used as a natural food colourant, with no significant toxicity at dietary levels.
• Well tolerated in trials. Purified anthocyanin mixtures (~320 mg/day, up to 24 weeks) were well tolerated in human RCTs ^{9,10,11Reference 9Zhu Y et al. · 2011Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individualsView study →Reference 10Zhu Y et al. · 2013RCTAnti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trialView study →Reference 11Qin Y et al. · 2009Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjectsView study →}.
• Can turn pro-oxidant. Like other polyphenols, C3G can flip from antioxidant to pro-oxidant at high concentration or with catalysing metals — “antioxidant” is condition-dependent ^{13Reference 13Abuja PM et al. · 1998Antioxidant and prooxidant activities of elderberry (Sambucus nigra) extract in low-density lipoprotein oxidationView study →}.
• Poorly absorbed; activity is partly its metabolites’. <1% is absorbed intact and most is converted to protocatechuic acid, so in-vitro potency does not translate to systemic exposure ^{1,2Reference 1Czank C et al. · 2013Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a ¹³C-tracer studyView study →Reference 2Vitaglione P et al. · 2007Protocatechuic acid is the major human metabolite of cyanidin-glucosidesView study →}.
• Human data are mixtures, not the isolate, and pregnancy/lactation is decided on the herb/product page, not here.

Dosage

There is no established or recommended human dose for isolated C3G. The figures below are research context, not a recommendation:

The human trial figures are for an anthocyanin mixture in which C3G is one of several pigments, not isolated C3G, and the rodent doses are not convertible to human self-dosing. These are doses studied in research and are not a personal recommendation.

References

1. Czank C, et al. (2013). Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a ¹³C-tracer study. The American Journal of Clinical Nutrition. https://pubmed.ncbi.nlm.nih.gov/23604435/
2. Vitaglione P, et al. (2007). Protocatechuic acid is the major human metabolite of cyanidin-glucosides. The Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/17709440/
3. de Ferrars RM, et al. (2014). The pharmacokinetics of anthocyanins and their metabolites in humans. British Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/24602005/
4. Kähkönen MP, Heinonen M (2003). Antioxidant activity of anthocyanins and their aglycons. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/12537433/
5. Tsuda T, et al. (2003). Dietary cyanidin 3-O-β-D-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in mice. The Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/12840166/
6. Oumeddour DZ, et al. (2024). Recent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: a comprehensive review. Biochemical and Biophysical Research Communications. https://pubmed.ncbi.nlm.nih.gov/38976946/
7. Wang Y, et al. (2012). Supplementation with cyanidin-3-O-β-glucoside protects against hypercholesterolemia-mediated endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E-deficient mice. The Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/22535762/
8. Wang D, et al. (2011). Cyanidin-3-O-β-glucoside with the aid of its metabolite protocatechuic acid, reduces monocyte infiltration in apolipoprotein E-deficient mice. Biochemical Pharmacology. https://pubmed.ncbi.nlm.nih.gov/21569764/
9. Zhu Y, et al. (2011). Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individuals. Clinical Chemistry. https://pubmed.ncbi.nlm.nih.gov/21926181/
10. Zhu Y, et al. (2013). Anti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trial. Nutrition, Metabolism and Cardiovascular Diseases. https://pubmed.ncbi.nlm.nih.gov/22906565/
11. Qin Y, et al. (2009). Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjects. The American Journal of Clinical Nutrition. https://pubmed.ncbi.nlm.nih.gov/19640950/
12. Wang LS, Stoner GD (2008). Anthocyanins and their role in cancer prevention. Cancer Letters. https://pubmed.ncbi.nlm.nih.gov/18571839/
13. Abuja PM, Murkovic M, Pfannhauser W (1998). Antioxidant and prooxidant activities of elderberry (Sambucus nigra) extract in low-density lipoprotein oxidation. Journal of Agricultural and Food Chemistry. https://doi.org/10.1021/jf980296g
14. Zanatta CF, et al. (2005). Determination of anthocyanins from camu-camu (Myrciaria dubia) by HPLC-PDA, HPLC-MS, and NMR. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/16302773/
15. Mikulic-Petkovsek M, et al. (2014). Investigation of anthocyanin profile of four elderberry species and interspecific hybrids. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/24830391/
16. da Silva FC, et al. (2019). Antigenotoxic and antimutagenic effects of Myrciaria dubia juice in mice submitted to ethanol 28-day treatment. Journal of Toxicological and Environmental Health, Part A. https://pubmed.ncbi.nlm.nih.gov/31570063/

View all 16 references▾