Compound Monograph
Ellagic Acid
A polyphenol you mostly don't absorb. In plants it's bound as ellagitannins (punicalagins etc.); free ellagic acid barely reaches the blood, and gut bacteria convert it to urolithins — the metabolites that actually circulate, and only in some people. So most "ellagic acid" evidence is really pomegranate/ellagitannin extract or the urolithin-A metabolite, not the isolate.
Sources · 22
Where Does It Come From?
Ellagic Acid is a naturally occurring polyphenol (hexahydroxydiphenic acid dilactone), found in Raspberry, Pomegranate, Blackberry and 19 other sources. It is well tolerated orally (low toxicity).
Source Acacia Acacia, Vachellia & Senegalia spp. Herb monograph →
Source Amla Phyllanthus emblica Herb monograph →
Source Babul Vachellia nilotica Herb monograph →
Source Bearberry Arctostaphylos uva-ursi Herb monograph →
Source Black Walnut Juglans nigra Herb monograph →
Source Camu-camu Myrciaria dubia Herb monograph →
Source Chanca Piedra Phyllanthus niruri Herb monograph →
Source Cramp Bark Viburnum opulus Herb monograph →
Source Eucalyptus Eucalyptus globulus Herb monograph →
Source Haritaki Terminalia chebula Herb monograph →
Source Raspberry Leaf Rubus idaeus Herb monograph → Concentration
Content by Source
Reported concentrations across the plants that contain ellagic acid — the bar marks the typical level, the line shows the reported range.
Literature figures for varying plant parts and preparations. Read them as a comparative guide, not exact assays.
Ellagic Acid at a Glance
Ellagic acid is a polyphenol found in pomegranate, walnuts and berries — though almost never in free form. In plants it is bound into ellagitannins such as punicalagins, and those are what food actually delivers.
What reaches your blood is not ellagic acid. Gut bacteria convert it into urolithins, and those metabolites are what circulate — which means the compound’s effects depend on your microbiome. People differ in which urolithins they produce, and some produce very little, so the same pomegranate juice does genuinely different things in different people.
Most human evidence attributed to ellagic acid therefore belongs to pomegranate extracts or to urolithin A, now studied in its own right for muscle and mitochondrial function.
What It's Used For
Ellagic acid is one of the most-studied dietary polyphenols, and one of the most over-attributed — because “ellagic acid” is really three different things. First, in plants it occurs mostly bound as ellagitannins (punicalagins, sanguiin, etc.), so the substance in a “pomegranate/ellagic acid” study is usually an ellagitannin extract, not the free molecule. Second, free ellagic acid is very poorly absorbed — plasma peaks around 0.06 µmol/L and absorption saturates, so swallowing more buys little 15Reference 15Bioavailability of ellagic acid in human plasma after consumption of ellagitannins from pomegranate (Punica granatum L.) juiceView study →.
Third, the species that actually circulate at meaningful concentrations are the gut-microbial metabolites urolithins (urolithin A/B), and only some people make them well — a person’s “urolithin metabotype” (A, B, or 0) gates the whole story 13,
So efficacy credited to “ellagic acid” usually belongs to an ellagitannin source or a downstream metabolite, and is filtered through the microbiome. Read every claim with that three-layer caveat.
Support is an experimental score I’m building — a composite weighted by study type (human > animal > in vitro > review) and study volume, tempered for isolate-vs-source-vs-metabolite match and bioavailability. It’s a beta: a fast way to rank strength of evidence at a glance, not a validated metric. Scores are capped hard for the attribution gaps — the “Rests on” column names which molecule each really tested. Each application links to its write-up.
The best-supported application — but the tested agent is pomegranate, not ellagic acid. Meta-analyses of RCTs find pomegranate juice/extract lowers both systolic and diastolic blood pressure 1Reference 1Meta-analysisEffects of pomegranate juice on blood pressure — a systematic review and meta-analysis of randomised controlled trialsView study →, with later meta-analyses reaffirming a modest systolic effect 2Reference 2Meta-analysisThe effects of pomegranate consumption on blood pressure in adults — a systematic review and meta-analysisView study → and a dose-response across cardiometabolic risk factors 3Reference 3Meta-analysisImpacts of supplementation with pomegranate on cardiometabolic risk factors — a systematic review and dose-response meta-analysisView study →. Proposed mechanism is punicalagin/ellagitannin-driven ACE and NF-κB modulation with eNOS/NO support.
Gap: every one of these is a whole-pomegranate intervention — the active fraction cannot be cleanly attributed to ellagic acid versus anthocyanins, intact punicalagins, or urolithins; there is no pure-ellagic-acid BP RCT of comparable weight, and heterogeneity (juice vs extract, dose, duration) is high 1,
The flashiest human data — and a different molecule. The trials give synthetic urolithin A (a supplement), precisely to bypass the absorption and metabotype problems of ellagic acid: a first-in-human study found it safe and inducing a mitochondrial/mitophagy signature 4Reference 4The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humansView study →, a 4-month RCT improved muscle strength and exercise-performance biomarkers 5Reference 5RCTUrolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomised trial in middle-aged adultsView study →, and an RCT in older adults reported muscle-endurance and mitochondrial signals 6Reference 6RCTEffect of urolithin A supplementation on muscle endurance and mitochondrial health in older adults — a randomised clinical trialView study →, with an athlete RCT adding endurance/inflammation effects 7Reference 7RCTAssessment of urolithin A effects on muscle endurance, strength, inflammation, oxidative stress and protein metabolism in male athletes with resistance training — an 8-week randomised, double-blind, placebo-controlled studyView study →.
Both flagship trials nonetheless missed their primary endpoints — peak power in 5Reference 5RCTUrolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomised trial in middle-aged adultsView study →, and both co-primaries (6-minute walk distance and maximal ATP production) in 6Reference 6RCTEffect of urolithin A supplementation on muscle endurance and mitochondrial health in older adults — a randomised clinical trialView study → — and an independent 2024 systematic review found no effect on maximal ATP, mitochondrial biogenesis, microbiota or physical function. See urolithin A for the full accounting.
Gap: this is good evidence for urolithin A, not ellagic acid. Functional endpoints are modest and biomarker-led, the trials are industry-associated, and — crucially — the results do not transfer to “ellagic acid supplementation” unless you are a urolithin-A producer, and even then ellagic acid delivers far less urolithin A than dosing the metabolite 4,
The rare genuine pure-isolate human data. Small RCTs of ellagic acid (~180–500 mg/day) report improved insulin sensitivity in metabolic syndrome 8Reference 8RCTEllagic acid effect on the components of metabolic syndrome, insulin sensitivity and insulin secretion — a randomised, double-blind, placebo-controlled clinical trialView study →, reduced insulin resistance with SIRT1/Fetuin-A changes in type 2 diabetes 9Reference 9RCTDecreased insulin resistance in diabetic patients by influencing Sirtuin1 and Fetuin-A following supplementation with ellagic acid — a randomised controlled trialView study →, and improved insulin resistance and hormonal measures in PCOS 10Reference 10RCTRandomised double-blind clinical trial evaluating the ellagic acid effects on insulin resistance, oxidative stress and sex-hormone levels in women with polycystic ovarian syndromeView study →.
Gap: small (tens of patients), short (8–12 weeks), surrogate/mechanistic endpoints (HOMA-IR, SIRT1, MDA), and clustered in a few research groups with no independent large-scale replication and no hard outcomes. Promising, genuinely the isolate, but early 8,
Ellagic acid shifts oxidative-stress markers (notably MDA) and some inflammatory cytokines across the metabolic RCTs and a single MS-with-depressive-symptoms trial 11Reference 11The effects of ellagic acid supplementation on neurotrophic, inflammation and oxidative stress factors, and IDO gene expression in multiple sclerosis patients with mild to moderate depressive symptomsView study →, while its anticancer pharmacology — apoptosis, cell-cycle arrest, anti-angiogenesis — is extensively documented in the laboratory 12Reference 12ReviewExperimental evidence of the antitumour, antimetastatic and antiangiogenic activity of ellagic acid — a reviewView study →.
Gap: the human anti-inflammatory data are biomarker-only with unestablished clinical meaning, and the anticancer evidence is entirely preclinical — no human efficacy trials, and cell studies use concentrations far above achievable plasma levels. Mechanistically rich, clinically unproven 11,
Mechanisms
| Target / pathway | Acting species | Evidence | Maps to |
|---|---|---|---|
| Antioxidant / radical scavenging (MDA ↓) | ellagic acid (isolate) | human biomarker RCTs | metabolicanti-inflammatory |
| Anti-inflammatory — NF-κB ↓, CRP/adhesion ↓ | ellagitannins + ellagic acid + urolithin A | human (pomegranate metas; urolithin A RCTs) | cardiovascularanti-inflammatory |
| Endothelial / vascular — ACE ↓, eNOS/NO ↑ | ellagitannins (punicalagin) | human RCT meta-analyses | blood pressure |
| Mitophagy / mitochondrial biogenesis (PGC-1α) | urolithin A (metabolite) | human RCTs | muscleaging |
| Insulin sensitization — SIRT1 ↑, HOMA-IR ↓ | ellagic acid (isolate) | small human RCTs | insulin resistanceT2DPCOS |
| Pro-apoptotic / anti-angiogenic | ellagic acid, high concentration | preclinical only | anticancer (unproven) |
Pharmacokinetics
Ellagic acid is the textbook case of a molecule whose blood levels never match its bench reputation — and it is largely a pro-drug for urolithins. Free ellagic acid has low solubility and only a narrow upper-intestinal absorption window; most dietary ellagic acid arrives bound in ellagitannins that hydrolyze in the gut to release it. Either way little reaches plasma intact: in the classic pomegranate-juice study it peaked at only ~0.06 µmol/L with a sub-hour half-life, cleared within hours 15Reference 15Bioavailability of ellagic acid in human plasma after consumption of ellagitannins from pomegranate (Punica granatum L.) juiceView study →, and pushing the free-ellagic-acid dose 20-fold does not raise plasma proportionally — absorption saturates. What circulates and persists is the downstream story: ellagic acid reaching the colon is progressively converted by microbiota to urolithins (C → A, and in some people isourolithin A / urolithin B), which are far better absorbed and enter blood as glucuronide/sulfate conjugates — though “better” is relative: total plasma urolithins run about 0.003–5.2 µM, while the tens-of-µM figures often quoted for urolithins are urinary, not circulating. They remain detectable in urine up to 48 h 16,
Crucially this conversion is not universal: people fall into reproducible urolithin metabotypes — A (only urolithin A), B (also isourolithin A/urolithin B), and 0 (essentially none) — consistent across trials regardless of food source, and shifting with age toward metabotype B and non-producers 13,
Clinical trials
Ellagic acid’s human literature is dominated by pomegranate/ellagitannin interventions (cardiovascular) and, more recently, by urolithin A (a metabolite dosed directly). Genuine pure-ellagic-acid efficacy RCTs are few, small and surrogate-endpoint.
| Pure ellagic acid | Pomegranate/ellagitannin | Urolithin A (metabolite) | Anticancer |
|---|---|---|---|
| Few small RCTs (metabolic) | Many RCTs + meta-analyses | Several RCTs | Preclinical only |
Last checked: July 2026.
Monoamine oxidase (MAO) inhibition
Unusually among dietary polyphenols, ellagic acid is a moderately potent, MAO-B-preferring inhibitor — a reported IC50 around 9.21 µM (Ki ≈ 7.5 µM) against MAO-B, with only weak MAO-A inhibition 14Reference 14Acetylcholinesterase and monoamine oxidase-B inhibitory activities by ellagic acid derivatives isolated from Castanopsis cuspidata var. sieboldiiView study → (the direction opposite to the MAO-A-preferring flavonols/flavones). An eye-catching nanomolar figure circulating from another paper is internally inconsistent; the ~9 µM value is the trustworthy one. Given ellagic acid’s very poor absorption this is more an in-vitro property than a clinical effect — see the natural MAO inhibitors guide.
Isolate vs. Plant Studies
Ellagic acid is over-attributed in three directions at once. The human cardiovascular evidence is pomegranate/ellagitannin, not free ellagic acid — the active fraction of a pomegranate extract can’t be assigned to ellagic acid over its punicalagins, anthocyanins or downstream urolithins 1Reference 1Meta-analysisEffects of pomegranate juice on blood pressure — a systematic review and meta-analysis of randomised controlled trialsView study →. The flashiest human data are a metabolite: the urolithin-A muscle/mitophagy trials dose urolithin A directly, precisely because ellagic acid delivers so little of it, and only in metabotype-A producers 4,
Prevalence in Nature
Ellagic acid occurs in plants overwhelmingly bound as ellagitannins — galloyl/hexahydroxydiphenoyl (HHDP) esters of glucose — rather than as the free aglycone, so food tables report total ellagic acid after hydrolysis, which is much higher than the free value 21Reference 21ReviewEllagic acid — a review on its natural sources, chemical stability and therapeutic potentialView study →. The richest sources cluster in a few families: pomegranate (punicalagins, concentrated in the peel/rind — up to ~3,900 mg/100 g dry weight, ~50× the edible arils, which is why the peel is the commercial extraction source even though it isn’t eaten); Rubus/Fragaria berries (cloudberry and raspberry the headliners, plus blackberry and strawberry; sanguiin H-6 and lambertianin C are the main ellagitannins); walnuts and pecans (pedunculagin); muscadine grapes (unusual among grapes in carrying ellagitannins); and oak — vescalagin/castalagin leach from barrels, so oak-aged wine and whisky pick up ellagic acid that unoaked drinks lack 21,
⚠ A sourcing caveat on the figures. The review that supplies most of the content-by-source numbers and much of the chemistry above has since been retracted 21Reference 21ReviewEllagic acid — a review on its natural sources, chemical stability and therapeutic potentialView study →. The compositional values it compiled are secondary data drawn from food tables and are not themselves in dispute, but they should be treated as unverified until re-sourced to a primary food-composition database.
Biosynthetically, gallic acid (from the shikimate pathway) is esterified onto glucose; oxidative C–C coupling of two adjacent galloyl groups forms the hexahydroxydiphenoyl (HHDP) ester that defines ellagitannins, and on hydrolysis the freed HHDP acid spontaneously lactonizes into the stable, planar dilactone that is ellagic acid 21,
Discovery & Synthesis
The name is a chemist’s in-joke: “ellagic” is “galle” — French for gallnut — spelled backwards (galle → ellag), signaling both its origin from oak galls (noix de galle) and its kinship with acide gallique, gallic acid. The compound is conventionally credited to Henri Braconnot around 1831, though secondary sources disagree (some cite ~1818, and Chevreul is sometimes named as first noticing it in gallnuts), and no primary indexed source confirms the attribution — so treat “Braconnot, ~1831” as the conventional account rather than a documented fact.
Structurally ellagic acid is a dimeric derivative of gallic acid — the dilactone of hexahydroxydiphenic acid: two gallic-acid units joined head-to-tail by a biaryl bond and locked by two lactone rings into a flat, rigid, four-ring planar polyphenol with four phenolic hydroxyls. That fused, planar, hydrogen-bonding structure is exactly why it is so poorly soluble in water — the physical property behind its poor absorption. Plants store little free ellagic acid; it (and commercial supply) is obtained by hydrolysis/extraction from ellagitannin-rich sources — oak galls, pomegranate peel, chestnut, walnut, berries. Total synthesis is possible but not the practical route; extraction is cheaper and the molecule’s low solubility makes purification the real work.
Patents: not yet researched (future patent-loop pass).
Toxicity & Safety
As an ordinary dietary polyphenol from pomegranate, berries, walnuts and oak-aged foods, ellagic acid has a reassuring safety record at food levels and low intrinsic toxicity — a 90-day rat study fed up to 5% of the diet (tens of g/kg/day) with no deaths or treatment-related toxicity 19Reference 19AnimalSafety assessment of ellagic acid, a food additive, in a subchronic toxicity study using F344 ratsView study →, and it is an accepted food antioxidant in Japan. The honest caveat: this record is for food-level, mostly ellagitannin-bound intake; safety of concentrated isolated-ellagic-acid supplements taken chronically at high doses is limited (and its poor, saturable absorption means much of a large dose simply passes through unabsorbed rather than being “safely handled” systemically).
The interaction worth flagging is with anticoagulants. In a controlled animal study ellagic acid (like quercetin) showed pharmacodynamic and pharmacokinetic interaction with warfarin — prolonging INR and inhibiting the CYPs that clear it (CYP2C9, CYP2C8, CYP3A4) 20Reference 20AnimalCritical pharmacokinetic and pharmacodynamic drug-herb interactions in rats between warfarin and pomegranate peel or guava leaves extractsView study →. This is animal/in-vitro, not proven in people, so hedge it — but the sensible advice is that anyone on warfarin or other anticoagulant/antiplatelet therapy treat high-dose ellagic acid or pomegranate-peel supplements as a potential additive bleeding-risk and CYP concern. As a polyphenol it can also bind non-heme iron in the gut, relevant to iron-deficiency.
Dosage
There is no evidence-based dose of isolated ellagic acid. The small pure-ellagic-acid metabolic trials used ~180–1,000 mg/day for 8–12 weeks 8,
These are descriptive research figures, not a recommendation — the pure-isolate evidence is small and preliminary, the muscle evidence is for a different molecule, and individual response is gated by the microbiome.
References
- Sahebkar A, Ferri C, Giorgini P, et al. (2017). Effects of pomegranate juice on blood pressure — a systematic review and meta-analysis of randomised controlled trials. Pharmacological Research, 115, 149–161. https://pubmed.ncbi.nlm.nih.gov/27888156/
- Bahari H, Omidian K, Goudarzi K, et al. (2024). The effects of pomegranate consumption on blood pressure in adults — a systematic review and meta-analysis. Phytotherapy Research, 38(5), 2234–2248. https://pubmed.ncbi.nlm.nih.gov/38410857/
- Mohammadi S, et al. (2025). Impacts of supplementation with pomegranate on cardiometabolic risk factors — a systematic review and dose-response meta-analysis. Nutrition, Metabolism and Cardiovascular Diseases. https://pubmed.ncbi.nlm.nih.gov/40617711/
- Andreux PA, Blanco-Bose W, Ryu D, et al. (2019). The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans. Nature Metabolism, 1(6), 595–603. https://pubmed.ncbi.nlm.nih.gov/32694802/
- Singh A, D’Amico D, Andreux PA, et al. (2022). Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomised trial in middle-aged adults. Cell Reports Medicine, 3(5), 100633. https://pubmed.ncbi.nlm.nih.gov/35584623/
- Liu S, D’Amico D, Shankland E, et al. (2022). Effect of urolithin A supplementation on muscle endurance and mitochondrial health in older adults — a randomised clinical trial. JAMA Network Open, 5(1), e2144279. https://pubmed.ncbi.nlm.nih.gov/35050355/
- Zhao H, et al. (2024). Assessment of urolithin A effects on muscle endurance, strength, inflammation, oxidative stress and protein metabolism in male athletes with resistance training — an 8-week randomised, double-blind, placebo-controlled study. Journal of the International Society of Sports Nutrition, 21(1). https://pubmed.ncbi.nlm.nih.gov/39487653/
- Hidalgo-Lozada GM, Villarruel-López A, Martínez-Abundis E, et al. (2022). Ellagic acid effect on the components of metabolic syndrome, insulin sensitivity and insulin secretion — a randomised, double-blind, placebo-controlled clinical trial. Journal of Clinical Medicine, 11(19), 5741. https://pubmed.ncbi.nlm.nih.gov/36233611/
- Ghadimi M, Foroughi F, Hashemipour S, et al. (2021). Decreased insulin resistance in diabetic patients by influencing Sirtuin1 and Fetuin-A following supplementation with ellagic acid — a randomised controlled trial. Diabetology & Metabolic Syndrome, 13(1), 16. https://pubmed.ncbi.nlm.nih.gov/33546744/
- Kazemi M, Lalooha F, Nooshabadi MR, et al. (2021). Randomised double-blind clinical trial evaluating the ellagic acid effects on insulin resistance, oxidative stress and sex-hormone levels in women with polycystic ovarian syndrome. Journal of Ovarian Research, 14(1), 100. https://pubmed.ncbi.nlm.nih.gov/34330312/
- Hajiluian G, et al. (2023). The effects of ellagic acid supplementation on neurotrophic, inflammation and oxidative stress factors, and IDO gene expression in multiple sclerosis patients with mild to moderate depressive symptoms. Phytomedicine, 121, 155094. https://pubmed.ncbi.nlm.nih.gov/37806153/
- Ceci C, Lacal PM, Tentori L, et al. (2018). Experimental evidence of the antitumour, antimetastatic and antiangiogenic activity of ellagic acid — a review. Nutrients, 10(11), 1756. https://pubmed.ncbi.nlm.nih.gov/30441769/
- Tomás-Barberán FA, García-Villalba R, González-Sarrías A, et al. (2014). Ellagic acid metabolism by human gut microbiota — consistent observation of three urolithin phenotypes in intervention trials, independent of food source, age and health status. Journal of Agricultural and Food Chemistry, 62(28), 6535–6538. https://pubmed.ncbi.nlm.nih.gov/24976365/
- Oh JM, Jang HJ, Kang MG, et al. (2021). Acetylcholinesterase and monoamine oxidase-B inhibitory activities by ellagic acid derivatives isolated from Castanopsis cuspidata var. sieboldii. Scientific Reports, 11(1), 13953. https://pubmed.ncbi.nlm.nih.gov/34230570/
- Seeram NP, Lee R, Heber D. (2004). Bioavailability of ellagic acid in human plasma after consumption of ellagitannins from pomegranate (Punica granatum L.) juice. Clinica Chimica Acta, 348(1–2), 63–68. https://pubmed.ncbi.nlm.nih.gov/15369737/
- Seeram NP, Henning SM, Zhang Y, et al. (2006). Pomegranate juice ellagitannin metabolites are present in human plasma and some persist in urine for up to 48 hours. The Journal of Nutrition, 136(10), 2481–2485. https://pubmed.ncbi.nlm.nih.gov/16988113/
- Espín JC, Larrosa M, García-Conesa MT, Tomás-Barberán F. (2013). Biological significance of urolithins, the gut microbial ellagic-acid-derived metabolites — the evidence so far. Evidence-Based Complementary and Alternative Medicine, 2013, 270418. https://pubmed.ncbi.nlm.nih.gov/23781257/
- Cortés-Martín A, Selma MV, Espín JC, García-Villalba R. (2018). The gut microbiota urolithin metabotypes revisited — the human metabolism of ellagic acid is mainly determined by aging. Food & Function, 9(8), 4100–4106. https://pubmed.ncbi.nlm.nih.gov/30004553/
- Tasaki M, Umemura T, Maeda M, et al. (2008). Safety assessment of ellagic acid, a food additive, in a subchronic toxicity study using F344 rats. Food and Chemical Toxicology, 46(3), 1119–1124. https://pubmed.ncbi.nlm.nih.gov/18155344/
- Alnaqeeb M, Mansor KA, Mallah EM, et al. (2019). Critical pharmacokinetic and pharmacodynamic drug-herb interactions in rats between warfarin and pomegranate peel or guava leaves extracts. BMC Complementary and Alternative Medicine, 19(1), 29. https://pubmed.ncbi.nlm.nih.gov/30678660/
- Sharifi-Rad J, Quispe C, Castillo CMS, et al. (2022). Ellagic acid — a review on its natural sources, chemical stability and therapeutic potential. Oxidative Medicine and Cellular Longevity, 2022, 3848084. https://pubmed.ncbi.nlm.nih.gov/35237379/ ⚠ RETRACTED — retraction notice: Oxid Med Cell Longev. 2024;2024:9801541, https://pubmed.ncbi.nlm.nih.gov/38234511/
- Koponen JM, Happonen AM, Mattila PH, Törrönen AR. (2007). Contents of anthocyanins and ellagitannins in selected foods consumed in Finland. Journal of Agricultural and Food Chemistry, 55(4), 1612–1619. https://pubmed.ncbi.nlm.nih.gov/17261015/
- Clifford MN, Scalbert A. (2000). Ellagitannins — nature, occurrence and dietary burden. Journal of the Science of Food and Agriculture, 80(7), 1118–1125. https://doi.org/10.1002/(SICI)1097-0010(20000515)80:7<1118::AID-JSFA570>3.0.CO;2-9
