Hydroxytyrosol
Also called HT, 3,4-dihydroxyphenylethanol, olive polyphenol.
Best grade C across 10 graded outcomes Other Last checked
The short answer
From 15 sourcesHydroxytyrosol is the main phenol in olives. The EU's food-safety agency accepted that 5 mg a day of hydroxytyrosol and related phenols in olive oil helps protect blood lipids from oxidation. Supplement trials are small: 15 mg a day lowered oxidised LDL in prediabetes, while a 30-day heart-function trial found no significant change.
Every graded outcome on this page
10 rows · line = participants- CGrade CCardiometabolic risk factors (cholesterol, triglycerides, insulin)Cholesteroln 594
- CGrade COxidised LDL, oxidative-stress and inflammation markers in adults with overweight and prediabetesOxidative stressn 49
- DGrade DCognitive test scores in middle-aged and older adultsCognitionn 72
- DGrade DBlood pressure in adults with raised systolic pressureBlood pressuren 54
- DGrade DEndothelial and arterial function in chronic coronary syndromeHeart functionn 30
- DGrade DBody weight and visceral fat in women with overweight or obesityBody weightn 29
- DGrade DAerobic exercise economy and recoveryExercisen 29
- DGrade DLDL particle number and LDL oxidationLDL oxidationn 25
- DGrade DHealth-related quality of life in children with mitochondrial diseaseMitochondrial diseasen 9
- ∅No effectHeart function and arterial stiffness in chronic coronary artery diseaseHeart functionn 61
- 7 more graded outcomes, in the evidence chapter
Key facts
- EU health claim
- EFSA accepted a cause-and-effect link with protection of LDL from oxidation at 5 mg/day of hydroxytyrosol and its derivatives in olive oil1
- Prediabetes trial
- 15 mg/day for 16 weeks lowered oxidised LDL versus placebo in 49 completers with prediabetes2
- Pooled evidence
- 14 studies (594 people) of olive phenols: small drops in cholesterol, triglycerides and insulin3
- Absorption
- Absorbed in a dose-dependent way; plasma levels peaked about 30 minutes after a supplement dose89
- Heart function
- Mixed: no significant change after 30 days of 10 mg/day in 61 patients with coronary disease; vascular measures improved from baseline in a 30-patient crossover at the same dose514
- Blood pressure
- An olive extract with 25 mg/day hydroxytyrosol did not lower blood pressure more than placebo over 8 weeks (54 adults)12
What it is
Hydroxytyrosol is a phenolic compound from olives and olive oil, sold as olive-fruit or olive-extract supplements.
How it works
ProposedForms, side by side
2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.
Hydroxytyrosol forms compared
2 forms| 2 forms | Olive-derived hydroxytyrosol supplement (liquid or capsule) | High-polyphenol olive oil |
|---|---|---|
| Absorption in people | In 12 volunteers, two olive-derived liquid supplements (about 31 and 61 mg hydroxytyrosol) were bioavailable, with higher exposure at the higher dose and a plasma peak at 30 minutes.8 | Olive oil phenols, including hydroxytyrosol, are absorbed in a dose-dependent way and excreted in urine as glucuronide conjugates.9 |
| GI tolerance | No adverse events in a 16-week trial at 15 mg/day.2 | Used as a normal food (25 mL/day) in the EUROLIVE trial.7 |
| Studied for | Oxidative-stress markers, cardiometabolic markers, heart function | LDL oxidation and particle number |
- Olive-derived hydroxytyrosol supplement (liquid or capsule)
- Absorption in people
- In 12 volunteers, two olive-derived liquid supplements (about 31 and 61 mg hydroxytyrosol) were bioavailable, with higher exposure at the higher dose and a plasma peak at 30 minutes.8
- GI tolerance
- No adverse events in a 16-week trial at 15 mg/day.2
- Studied for
- Oxidative-stress markers, cardiometabolic markers, heart function
- High-polyphenol olive oil
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Trial map
10 graded outcomes, largest study first10 graded outcomes: 5 improved, 3 mixed, 2 no effect. The largest, a 2025 meta-analysis of 594 people on cardiometabolic risk factors (cholesterol, triglycerides, insulin), found an improvement.
1Cardiometabolic risk factors (cholesterol, triglycerides, insulin)
Improved · Grade C · Meta-analysis, 594 people, 2025
14 human intervention studies (594 participants)
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Cardiometabolic risk factors (cholesterol, triglycerides, insulin) | Improved | 594 | Grade C · Meta-analysis, 2025 | 14 human intervention studies (594 participants) |
| Cognitive test scores in middle-aged and older adults | Mixed | 72 | Grade D · RCT, 2023 | Japanese adults aged 51–82 |
| Heart function and arterial stiffness in chronic coronary artery disease | No effect | 61 | No-effect grade · Crossover RCT, 2023 | Patients with chronic coronary artery disease, aged 70 or younger |
| Blood pressure in adults with raised systolic pressure | No effect | 54 | Grade D · RCT, 2026 | Adults with systolic blood pressure of 130 mm Hg or more (56 randomised, 54 analysed) |
| Oxidised LDL, oxidative-stress and inflammation markers in adults with overweight and prediabetes | Improved | 49 | Grade C · RCT, 2025 | Adults aged 40–70 with overweight and prediabetes (52 randomised, 49 completed) |
| Endothelial and arterial function in chronic coronary syndrome | Improved | 30 | Grade D · Crossover RCT, 2023 | Patients with chronic coronary artery syndrome |
| Aerobic exercise economy and recovery | Mixed | 29 | Grade D · RCT, 2023 | Recreationally active adults, mean age 42 |
| Body weight and visceral fat in women with overweight or obesity | Mixed | 29 | Grade D · RCT, 2022 | Women with overweight or obesity (three arms) |
| LDL particle number and LDL oxidation | Improved | 25 | Grade D · Crossover RCT, 2015 | Healthy European men aged 20–59 (EUROLIVE substudy) |
| Health-related quality of life in children with mitochondrial disease | Improved | 9 | Grade D · Open-label trial, 2025 | Children with genetic mitochondrial diseases |
Every graded row
10 rowsShowing 10 of 10 outcomes. Human trials only.
CGrade CCardiometabolic risk factors (cholesterol, triglycerides, insulin)CholesterolImprovedMeta-analysis · 14 studies
n 594 · 2025
Improved Small pooled reductions in total cholesterol (SMD −0.19), triglycerides (SMD −0.32) and insulin (SMD −0.42), with high heterogeneity for triglycerides and insulin (I² 73–78%). The authors say further studies are needed.
- Design
- Meta-analysis, 14 studies, n = 594, 2025
- Population
- 14 human intervention studies (594 participants)
- Form
- Oleuropein, hydroxytyrosol or tyrosol supplements (pooled)
- Dose
- Varied by study
- Duration
- Varied by study
- Source
- Reference 3 · PubMed 39828996 (opens PubMed)
CGrade COxidised LDL, oxidative-stress and inflammation markers in adults with overweight and prediabetesOxidative stressImprovedRCT
n 49 · 2025
Improved Compared with placebo, oxidised LDL, protein carbonyls and 8-OHdG fell, total antioxidant status and GPx activity were maintained, and IL-6 was lower (p = 0.05). Lipid profile, body measurements, sleep, well-being and physical capacity did not change. No adverse events were observed.
- Design
- RCT, n = 49, 2025
- Population
- Adults aged 40–70 with overweight and prediabetes (52 randomised, 49 completed)
- Form
- Hydroxytyrosol capsules
- Dose
- 15 mg/day
- Duration
- 16 weeks
- Source
- Reference 2 · PubMed 40690822 (opens PubMed)
DGrade DCognitive test scores in middle-aged and older adultsCognitionMixedRCT
n 72 · 2023
Mixed Only complex attention showed a significant time × group interaction (p = 0.049). Other domains improved over time in both groups.
- Design
- RCT, n = 72, 2023
- Population
- Japanese adults aged 51–82
- Form
- Desert olive tree pearls (an olive product high in hydroxytyrosol) in olive oil
- Dose
- 3 g twice daily (hydroxytyrosol dose not stated in the abstract)
- Duration
- 12 weeks
- Source
- Reference 6 · PubMed 37513652 (opens PubMed)
DGrade DBlood pressure in adults with raised systolic pressureBlood pressureNo effectRCT
n 54 · 2026
No effect Systolic pressure fell 8.3 mm Hg with the extract and 7.3 mm Hg with placebo, not a significant difference. Total cholesterol, LDL and apo B fell in both groups, also without a between-group difference. The extract was well tolerated.
- Design
- RCT, n = 54, 2026
- Population
- Adults with systolic blood pressure of 130 mm Hg or more (56 randomised, 54 analysed)
- Form
- Standardised olive dry extract capsules
- Dose
- 440 mg/day of extract (25 mg hydroxytyrosol and 123.5 mg oleuropein)
- Duration
- 8 weeks
- Source
- Reference 12 · PubMed 41805711 (opens PubMed)
DGrade DEndothelial and arterial function in chronic coronary syndromeHeart functionImprovedCrossover RCT
n 30 · 2023
Improved Glycocalyx thickness, flow-mediated dilation, coronary flow reserve and pulse wave velocity improved from baseline with hydroxytyrosol but not with placebo; malondialdehyde, oxidised LDL, triglycerides, PCSK9 and CRP fell, in contrast to placebo. Blood pressure did not change.
- Design
- Crossover RCT, n = 30, 2023
- Population
- Patients with chronic coronary artery syndrome
- Form
- Olive oil capsules (412.5 mg) each with 2.5 mg hydroxytyrosol
- Dose
- 4 capsules a day (10 mg hydroxytyrosol)
- Duration
- 1 month per period
- Source
- Reference 14 · PubMed 36912212 (opens PubMed)
DGrade DBody weight and visceral fat in women with overweight or obesityBody weightMixedRCT
n 29 · 2022
Mixed At 15 mg/day, weight (p = 0.012) and visceral fat (p = 0.006) fell more than with placebo after 4 weeks, but the difference faded by weeks 12 and 24. Hydroxytyrosol was safe and well tolerated over 6 months.
- Design
- RCT, n = 29, 2022
- Population
- Women with overweight or obesity (three arms)
- Form
- Hydroxytyrosol capsules
- Dose
- 5 or 15 mg/day
- Duration
- 24 weeks
- Source
- Reference 13 · PubMed 35406139 (opens PubMed)
DGrade DAerobic exercise economy and recoveryExerciseMixedRCT
n 29 · 2023
Mixed After the olive phytocomplex, the oxygen-uptake time constant at exercise onset (p = 0.005), the running-economy measure at the first lactate threshold (p = 0.015) and perceived exertion at the lactate turnpoint (p = 0.003) were lower, and one recovery measure was faster (p = 0.02). Time to exhaustion rose 4.1%, not significantly different from placebo.
- Design
- RCT, n = 29, 2023
- Population
- Recreationally active adults, mean age 42
- Form
- Hydroxytyrosol-rich olive fruit water phytocomplex (liquid)
- Dose
- 2 × 28 mL/day (hydroxytyrosol content not stated in the abstract)
- Duration
- 16 days
- Source
- Reference 15 · PubMed 36678293 (opens PubMed)
DGrade DLDL particle number and LDL oxidationLDL oxidationImprovedCrossover RCT
n 25 · 2015
Improved After the high-polyphenol oil, apolipoprotein B-100 and total and small LDL particle numbers fell, differing significantly from the low-polyphenol oil; LDL oxidation lag time rose 5% from baseline (significant only versus baseline, not versus the low-polyphenol oil).
- Design
- Crossover RCT, n = 25, 2015
- Population
- Healthy European men aged 20–59 (EUROLIVE substudy)
- Form
- High- versus low-polyphenol raw olive oil
- Dose
- 25 mL/day
- Duration
- 3 weeks per period
- Source
- Reference 7 · PubMed 26136585 (opens PubMed)
DGrade DHealth-related quality of life in children with mitochondrial diseaseMitochondrial diseaseImprovedOpen-label trial
n 9 · 2025
Improved Quality-of-life scores (PedsQL) showed the largest change; the authors report possible benefit in a MELAS subgroup and say the supplement was tolerated.
- Design
- Open-label trial, n = 9, 2025
- Population
- Children with genetic mitochondrial diseases
- Form
- Hydroxytyrosol dietary supplement
- Dose
- Not stated in the abstract
- Duration
- 12 months, then randomised to stop or continue for 6 months
- Source
- Reference 10 · PubMed 40481516 (opens PubMed)
∅No effectHeart function and arterial stiffness in chronic coronary artery diseaseHeart functionNo effectCrossover RCT
n 61 · 2023
No effect No significant change in left atrial or left ventricular function, central aortic pressure or augmentation index versus placebo; E/e′ (p = 0.062) and pulse wave velocity (p = 0.091) only trended toward improvement.
- Design
- Crossover RCT, n = 61, 2023
- Population
- Patients with chronic coronary artery disease, aged 70 or younger
- Form
- Olive oil extract (500 mg capsules) enriched with 5 mg hydroxytyrosol each
- Dose
- Two capsules a day (10 mg hydroxytyrosol)
- Duration
- 30 days per period
- Source
- Reference 5 · PubMed 37967452 (opens PubMed)
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
Markers move, function has not
Pooled data mix three compounds
The 2025 meta-analysis pooled oleuropein, hydroxytyrosol and tyrosol, so its small cholesterol and insulin effects are not specific to hydroxytyrosol.3
Studied doses
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
Doses studied in human trials ranged from about 5 mg/day of hydroxytyrosol (the low end in a 2024 review of randomised trials, and the low arm of a 24-week weight trial) to 25 mg/day in an olive extract that also supplied 123.5 mg oleuropein, for 8 weeks. 15 mg/day was used for 16 to 24 weeks and 10 mg/day in 1-month coronary-disease trials. Single doses of about 31 and 61 mg were used only to measure absorption. These are research doses, not recommendations.2458121314
When trials measured an effect
1 outcome| Outcome | Measured at | Basis |
|---|---|---|
| Body weight and visceral fat (15 mg/day) | Week 4; the difference from placebo faded by weeks 12 and 24 | 24-week trial in 29 women with overweight or obesity13 |
Interactions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
What Hydroxytyrosol meets
0 cited rows 2 tested togetherMedicines 0
No medicine rows in our sources.
Supplements and foods 1
- Tested together in a graded trial
Choose a medicine or supplement above to read its cited rows here.
Also cited: 2 tested together
PunicalaginsPunicalagins page
Tested together
Endothelial function, blood pressure and oxidised LDL (subgroups). Graded on the Punicalagins page; tested together is not a claim that they work better together.
Tested together
Blood lipids (subgroups). Graded on the Punicalagins page; tested together is not a claim that they work better together.
Interactions
0 agentsNone found in our sources.
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Hydroxytyrosol and your picks, and between your picks.
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Add a supplement or medicine you take to check it against Hydroxytyrosol.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
2 groups- Pregnancy, breastfeeding and children
- No reliable data. EFSA judged synthetic hydroxytyrosol safe as a food ingredient but left children under 3 years and pregnant and breastfeeding women out of the population it assessed, and LactMed has no hydroxytyrosol entry (checked October 2026). Supplement trials enrolled adults, apart from a 9-patient supervised pilot in children with mitochondrial disease.1110
Regulatory status
2 notesApproved claim in the EU, limited to olive oil.
- European Union
- EFSA concluded that olive polyphenols standardised to hydroxytyrosol and its derivatives protect LDL particles from oxidative damage at 5 mg/day of hydroxytyrosol and its derivatives in olive oil.1
- EU novel food
- EFSA concluded that chemically synthesised hydroxytyrosol is safe as a novel food added to fish and vegetable oils (up to 215 mg/kg) and margarines (up to 175 mg/kg), for a general population that excludes children under 3 years and pregnant and breastfeeding women.11
How the body handles hydroxytyrosol
2 notesFast absorption, mostly as metabolites.
- Peak and metabolites
- Plasma levels peaked 30 minutes after a supplement dose; homovanillic acid, hydroxytyrosol-3-O-sulphate and 3,4-dihydroxyphenylacetic acid were the main metabolites in plasma and urine.8
Reading the label, and the cost per dose
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
How to read the label
2 checksHydroxytyrosol or olive polyphenols?
Labels may list total olive polyphenols, hydroxytyrosol, or hydroxytyrosol plus derivatives such as oleuropein and tyrosol. The EU claim counts hydroxytyrosol and its derivatives together.1
Have the bottle? Photograph its Supplement Facts panel and see each line, hydroxytyrosol included, beside the doses and forms the trials used in Label X-Ray.
Cost per studied dose, without the sales pitch
Your numbers, no product dataEnter the price, servings and the amount per serving from your label.
Frequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
7 answersDoes hydroxytyrosol lower cholesterol?
Does it help memory?
One 12-week trial of an olive product found a change in only one attention measure, so the evidence is weak.6
Is hydroxytyrosol safe to take long term?
How quickly is it absorbed?
In volunteers, plasma levels peaked about 30 minutes after a liquid supplement dose.8
Does hydroxytyrosol interact with medications?
No interactions are documented. LiverTox, LactMed, NCCIH and MedlinePlus have no hydroxytyrosol entry (checked October 2026), and the trials cited here reported none; interactions have not been formally studied.
Is a hydroxytyrosol supplement better than olive oil?
What does the EU health claim say?
That olive oil polyphenols help protect blood lipids from oxidative stress, at 5 mg/day of hydroxytyrosol and its derivatives in olive oil.1
Sources
15 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
15 sources- 1Scientific Opinion on the substantiation of health claims related to polyphenols in olive and protection of LDL particles from oxidative damage (ID 1333, 1638, 1639, 1696, 2865) and other claims pursuant to Article 13(1) of Regulation (EC) No 1924/2006Guideline EFSA Journal (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2011 · efsa.onlinelibrary.wiley.com
- 2Hydroxytyrosol supplementation improves antioxidant and anti-inflammatory status in individuals with overweight and prediabetes: A randomized, double-blind, placebo-controlled parallel trial.RCT Clin Nutr, 2025 · PMID 40690822
- 3The impact of oleuropein, hydroxytyrosol, and tyrosol on cardiometabolic risk factors: a meta-analysis of randomized controlled trials.Meta-analysis Crit Rev Food Sci Nutr, 2025 · PMID 39828996
- 4Systemic Health Effects of Oleuropein and Hydroxytyrosol Supplementation: A Systematic Review of Randomized Controlled Trials.Systematic review Antioxidants (Basel), 2024 · PMID 39334699
- 5The Short-Term Effect of Olive Oil Extract Enriched with Hydroxytyrosol on Cardiovascular Function.Crossover RCT J Med Food, 2023 · PMID 37967452
- 6Effects of Desert Olive Tree Pearls Containing High Hydroxytyrosol Concentrations on the Cognitive Functions of Middle-Aged and Older Adults.RCT Nutrients, 2023 · PMID 37513652
- 7Olive Oil Polyphenols Decrease LDL Concentrations and LDL Atherogenicity in Men in a Randomized Controlled Trial.Crossover RCT J Nutr, 2015 · PMID 26136585
- 8Oral Bioavailability and Metabolism of Hydroxytyrosol from Food Supplements.PK study Nutrients, 2023 · PMID 36678196
- 9Olive oil phenolics are dose-dependently absorbed in humans.PK study FEBS Lett, 2000 · PMID 10692578
- 10Open-label pilot study using hydroxytyrosol as dietary supplements in patients with mitochondrial diseases.Open-label trial Orphanet J Rare Dis, 2025 · PMID 40481516
- 11Safety of hydroxytyrosol as a novel food pursuant to Regulation (EC) No 258/97.Guideline EFSA J (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2017 · PMID 32625437
- 12Evaluation of the effect of olive extracts on blood pressure and cardiovascular health markers in adults: Findings from a double-blind, placebo-controlled, randomised trial.RCT PLoS One, 2026 · PMID 41805711
- 13Effect of Long-Term Hydroxytyrosol Administration on Body Weight, Fat Mass and Urine Metabolomics: A Randomized Double-Blind Prospective Human Study.RCT Nutrients, 2022 · PMID 35406139
- 14Association of hydroxytyrosol enriched olive oil with vascular function in chronic coronary disease.Crossover RCT Eur J Clin Invest, 2023 · PMID 36912212
- 15The Effect of a Hydroxytyrosol-Rich, Olive-Derived Phytocomplex on Aerobic Exercise and Acute Recovery.RCT Nutrients, 2023 · PMID 36678293
What changed
Every dated change to this page: what changed, who made it and why.
Change log
4 entries| Date | Change | Who and why |
|---|---|---|
| all | Audit: added graded rows for blood pressure (2026 olive-extract RCT, n = 54, no difference; n from full text), vascular function in coronary disease (2023 crossover, n = 30), body weight and visceral fat (2022 24-week RCT, n = 29) and aerobic exercise (2023 RCT, n = 29); the EFSA 2017 novel-food safety opinion for the pregnancy, breastfeeding and young-children note and a regulatory note; widened studied doses to 5–25 mg/day over 4–24 weeks; time-to-effect rows; cost per studied dose; FAQ on supplement versus olive oil, long-term safety and interactions; heart and metabolic goal links; corrected the prediabetes trial's n from 52 randomised to 49 analysed. Checked LiverTox, LactMed, NCCIH and MedlinePlus: no hydroxytyrosol entry and no documented interactions, so the interaction list stays empty. Skipped: a 2025 Chinese MAFLD trial (PMID 41114530; abstract gives no n or dose, no free full text), a 2025 platelet multi-omics study (no outcome numbers in the abstract), combination products (hydroxytyrosol with vitamin E, punicalagin or other ingredients) and a 2023 COVID-19 trial that was retracted. | Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md |
| Goals | Added the Brain & focus goal (focus): the page already has a graded human row on a memory or thinking outcome (“Cognitive test scores in middle-aged and older adults”, Grade D). No evidence row, grade or text changed. | Writer: Kymata Health EditorialTrigger: Update |
| all | Independent adversarial review: relabelled the 16-week prediabetes trial key fact; it is not the largest supplement trial cited (the coronary-disease crossover enrolled 61 and the olive-pearl trial 72). | Writer: Kymata Health EditorialTrigger: review |
| all | Initial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice. | Writer: Kymata Health EditorialTrigger: new page |
Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.