Hydroxytyrosol
Also known as: 3,4-dihydroxyphenylethanol, HXT, HT
Randomized trials and a meta-analysis of interventions with hydroxytyrosol or related olive phenolics report reductions in oxidative stress markers and modest favourable effects on some cardiometabolic endpoints (cholesterol, triglycerides, insulin). Trials in overweight/prediabetic adults and people with fatty liver report improvements in biomarkers; bioavailability from supplements is demonstrated but variable.
Last reviewed: 2026-10-14 · 5 indexed studies
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Overview
Hydroxytyrosol is an olive-derived phenolic compound found in olive oil, olives and some supplements. Human trials report improvements in oxidative stress and some cardiometabolic markers, and there is emerging evidence for benefits in fatty liver disease and modulation of the gut microbiota.
Mechanism & Function
Mechanism of Action
Hydroxytyrosol acts as an antioxidant and anti-inflammatory polyphenol and may modulate gut microbial composition and metabolite production (for example butyrate), which could mediate effects on liver and metabolic function.
Physiological Role
Scavenges reactive oxygen species and alters inflammatory signalling; may influence gut microbiota composition and microbial metabolites linked to metabolic homeostasis.
Primary Pathways
Performance / Health Relevance
Not a direct ergogenic compound; potential indirect benefits via improved metabolic health and reduced oxidative stress could support general health and recovery in at-risk populations.
Evidence Review
Practical Use & Dosage
- Minimum Effective Dose
- 15 mg/day (observed in a 16‑week RCT showing reduced oxLDL and oxidative markers)
- Optimal Range
- 15–60 mg/day (based on single-dose bioavailability data showing higher plasma exposure with higher single doses and trials using ~15 mg/day)
- Upper / Caution Level
- Not established
- Timing
- Not established from provided trials; single-dose pharmacokinetics show peak plasma levels around 30 minutes
- Best Format
- Standardised olive-derived hydroxytyrosol supplement (oral)
- Bioavailability
- Hydroxytyrosol is bioavailable from free and conjugated forms; plasma metabolites peak about 30 minutes after oral intake and urinary excretion shows main metabolites such as HT‑3‑O‑sulphate and homovanillic acid.
- Absorption Considerations
- Marked inter-individual variability in absorption and metabolism has been reported.
Safety & Interactions
Side Effects
- •No adverse events reported in the provided human trials
Contraindications
- None reported in the provided abstracts
Drug Interactions
- •Not reported in the provided abstracts
Who Should Avoid
- •Pregnancy and lactation: safety not established in the provided abstracts
Monitoring
No specific monitoring guidance provided in the cited trials; clinical monitoring should follow usual care for at‑risk populations.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Hydroxytyrosol typically used or indicated?
Hydroxytyrosol is most commonly used for: Antioxidant support, Cardiometabolic risk reduction, Liver health / fatty liver support, General ageing / oxidative stress prevention. Scavenges reactive oxygen species and alters inflammatory signalling; may influence gut microbiota composition and microbial metabolites linked to metabolic homeostasis.
How does Hydroxytyrosol work?
Hydroxytyrosol acts as an antioxidant and anti-inflammatory polyphenol and may modulate gut microbial composition and metabolite production (for example butyrate), which could mediate effects on liver and metabolic function.
What is the recommended dose of Hydroxytyrosol?
The optimal range is 15–60 mg/day (based on single-dose bioavailability data showing higher plasma exposure with higher single doses and trials using ~15 mg/day). with a minimum effective dose of 15 mg/day (observed in a 16‑week RCT showing reduced oxLDL and oxidative markers). Best taken: Not established from provided trials; single-dose pharmacokinetics show peak plasma levels around 30 minutes. Upper / caution level: Not established.
What are the side effects of Hydroxytyrosol?
Reported side effects include: No adverse events reported in the provided human trials. Monitoring: No specific monitoring guidance provided in the cited trials; clinical monitoring should follow usual care for at‑risk populations.
Does Hydroxytyrosol interact with medications?
Known or theoretical interactions: Not reported in the provided abstracts. Always check with a clinician before combining with prescription medication.
Who should avoid Hydroxytyrosol?
Hydroxytyrosol is generally not recommended for: Pregnancy and lactation: safety not established in the provided abstracts; and None reported in the provided abstracts.
How strong is the evidence for Hydroxytyrosol?
Evidence level: Moderate (overall score 74/100), based on 5 indexed studies on SuppIndex.
Research & References (5)
Hydroxytyrosol Improves Metabolic Dysfunction-Associated Fatty Liver Disease Dependent on the Modulation of Gut Microbiota.
8‑week randomized placebo‑controlled trial in patients with metabolic dysfunction‑associated fatty liver disease reporting mitigation of liver injury and steatosis and improvements in systemic glucolipid metabolism; metagenomic analysis linked changes in gut bacteria (notably Fusicatenibacter saccharivorans) and fecal butanoic acid with metabolic improvements; fecal microbiota transplantation in mice supported a role for microbiota changes.
Oral Bioavailability and Metabolism of Hydroxytyrosol from Food Supplements.
Randomized, controlled, blinded, cross‑over study in 12 healthy volunteers comparing two olive‑derived watery supplements (30.58 and 61.48 mg HT per dose) and HT‑fortified olive oil; pharmacokinetic analysis showed dose‑dependent bioavailability with peak plasma concentrations about 30 minutes after intake and identification of main plasma and urinary metabolites.
The impact of oleuropein, hydroxytyrosol, and tyrosol on cardiometabolic risk factors: a meta-analysis of randomized controlled trials.
Meta‑analysis of 14 randomized controlled trials (594 participants) assessing oleuropein, hydroxytyrosol and tyrosol on cardiometabolic risk factors; pooled analyses showed small but statistically significant reductions in total cholesterol, triglycerides and insulin.
Antioxidant activity of Hydroxytyrosol and Vitamin E reduces systemic inflammation in children with paediatric NAFLD.
Study in children with biopsy‑proven NAFLD treated with a combination of hydroxytyrosol and vitamin E for four months; the combination reduced oxidative damage markers (4‑HNE, 8‑OHdG) and influenced inflammatory cytokines (increased IL‑10, decreased IL‑6) with correlations between oxidative marker changes and triglyceride/steatosis improvements.
Hydroxytyrosol supplementation improves antioxidant and anti-inflammatory status in individuals with overweight and prediabetes: A randomized, double-blind, placebo-controlled parallel trial.
Randomized, double‑blind, placebo‑controlled parallel trial in adults with overweight and prediabetes given 15 mg/day hydroxytyrosol or placebo for 16 weeks; supplementation reduced oxidized LDL, protein carbonyls, 8‑OHdG and IL‑6 and prevented declines in total antioxidant status and GPx activity; no adverse events reported.
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Research Overview
Moderate EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/hydroxytyrosol
SuppIndex. (2026). Hydroxytyrosol: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/hydroxytyrosol
Based on 5 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Has been studied in combination with vitamin E in paediatric NAFLD; combination makes attribution of effects to hydroxytyrosol alone difficult.