IngredientsTyrosol is classified as a phenylethanoid, a derivative of phenethyl alcohol, and is found in a variety of natural sources. Its chemical structure consists of a benzene ring, a hydroxyl group (–OH), and a hydroxyethyl side chain (–CH2CH2OH). Tyrosol carries the synonyms (2-hydroxyethyl)phenol, p-hydroxyphenethyl alcohol, and 2-(4-hydroxyphenyl)ethanol. The compound is a colorless solid. Its CAS registry number is 501-94-0, and its molecular formula is C8H10O2 (molecular weight 138.16 g/mol).
According to plant secondary metabolic pathways, tyrosol's precursor is derived from the Shikimate pathway. Two main biosynthetic routes have been proposed: first, tyrosol may be derived from p-coumaric acid produced by the phenylpropane metabolic pathway, originating from phenylalanine; second, tyramine — an intermediate of the alkaloid metabolic pathway originating from tyrosine — may serve as a precursor of tyrosol biosynthesis. In Rhodiola rosea, the biosynthetic pathway involves a pyridoxal phosphate-dependent 4-hydroxyphenylacetaldehyde (4-HPAA) synthase that converts tyrosine to 4-HPAA, which is further reduced to tyrosol by 4-HPAA reductase.
The principal source of tyrosol in the human diet is olive oil. Tyrosol is a phenolic compound found especially in olives and olive oil, wine, and several other herbal products. Along with hydroxytyrosol and their secoiridoid derivatives, these compounds constitute approximately 90% of the total phenolic content of virgin olive oil.
Beyond olive oil, tyrosol has been identified across a broad range of botanical and food sources:
Since tyrosol is a minor phenolic component of olive oil, its bioactive potential was for a long time overshadowed by other olive phenolics, particularly hydroxytyrosol. However, over the years, evaluation of many different botanical sources has revealed the presence of tyrosol in them.
Tyrosol is a representative phenolic compound; hydroxytyrosol (HT) is its hydroxylated product. Distributed in olive oil and red wine, tyrosol is the aglycone and also an in vivo metabolite of salidroside. Studies have confirmed that salidroside is extensively metabolized to tyrosol after intravenous administration, and tyrosol was identified as the main form present in all rat tissues.
Tyrosol is encountered in several forms relevant to research and supplementation:
Tyrosol as an isolated compound is a modern subject of scientific investigation; historically, human populations were exposed to it indirectly through olive products, wine, and medicinal plants such as Rhodiola rosea. The traditional contexts in which these sources were used are well documented.
The traditional Mediterranean diet, characterized by regular intake of olive oil, has been associated with many health-benefiting effects experienced by Mediterranean populations. Reduced incidence of different chronic degenerative diseases, major cardiovascular events, type 2 diabetes mellitus, and some types of cancer, improved cognitive function, and protection against overall morbidity and mortality are confirmed by a respectable number of trials and epidemiological studies in humans adhering to this diet. The Mediterranean diet, which has been followed in Greece for centuries, is a modern object of scientific study. The phenolic constituents of olive oil — including tyrosol — are understood to be a contributing component, although ancient and medieval practitioners recognized the benefits of olive oil empirically, not at the level of individual phenolics.
Rhodiola rosea has a long history of use in traditional medicine to stimulate the nervous system, treat stress-induced fatigue and depression, enhance physical performance and work productivity, and treat gastrointestinal ailments and impotence. The roots and rhizomes of Rhodiola rosea L. (Crassulaceae), which is widely growing in Northern Europe, North America, and Siberia, have been used since ancient times to alleviate stress, fatigue, and mental and physical disorders. Within this plant, salidroside, the trans-cinnamyl alcohol glycoside compounds (rhodiolin, rosin, rosavin, rosarin, and rosiridin), and tyrosol are thought to be the most critical plant constituents needed for therapeutic activity.
Rhodiola rosea, also known as "golden root," "Arctic root," and "roseroot," is a plant originating from Europe and Asia. It has been used in traditional medicine for its adaptogenic and anti-inflammatory effects to enhance performance and reduce weakness due to fatigue and infection. An "adaptogen" is an agent conferring non-specific resistance against adverse biological, chemical, and physical stressors. Its rhizome and root have a long history of being used as a traditional medicine and functional food owing to the multiple bioactive compounds present, such as salidroside, tyrosol, gallic acid, and epigallocatechin gallate (EGCG).
Tyrosol is a phenolic compound present in two of the traditional components of the Mediterranean diet: wine and virgin olive oil. Its presence has been described in both red and white wines. Fermented beverages containing tyrosol have been part of Mediterranean and European traditions for millennia, though their phenolic composition was only systematically characterized in the modern era.
Tyrosol demonstrates antioxidant and anti-inflammatory properties by reducing reactive oxygen species, restoring antioxidant enzymes, and modulating inflammatory pathways. In spite of its weak direct antioxidant activity, tyrosol is effective in preserving cellular antioxidant defenses, probably by intracellular accumulation. This distinction is important: tyrosol is classified as a monophenol and is a weaker direct radical scavenger compared to its hydroxylated derivative, hydroxytyrosol, which carries two hydroxyl groups on its aromatic ring.
Extra virgin olive oil has been associated with a reduced incidence of risk factors for coronary heart disease, partly owing to the presence of antioxidant biophenols. Studies have compared the protective effects of tyrosol and hydroxytyrosol — two biophenols greatly different in direct antioxidant power — on macrophage-mediated oxidation of LDL. Both biophenols inhibited cell-mediated oxidation of LDL, though to a different extent (100% inhibition for hydroxytyrosol versus approximately 40% for tyrosol), and both counteracted the impairment of antioxidant cellular defenses including GSH and related enzymes.
A key mechanistic discovery is that tyrosol serves as a precursor to the potent antioxidant hydroxytyrosol in the human body. Once consumed, tyrosol converts into hydroxytyrosol in the human body, which is one of the newly established mechanisms of its potential bioactivity. Research demonstrates for the first time that cytochrome P450 enzymes (CYPs) convert tyrosol into hydroxytyrosol, and that this reaction is primarily mediated by two polymorphic CYP isoenzymes, CYP2D6 and CYP2A6. Experiments using human genotyped livers showed interindividual variability in hydroxytyrosol formation and supported the finding that CYP2D6 and CYP2A6 mediate this reaction.
Tyrosol has been reported to reduce oxidative stress in several types of cells — including in olive oil contexts where its phenolic constituent attenuates dioxin-induced toxicity in peripheral blood mononuclear cells via an antioxidant-dependent mechanism, and in protective effects against oxidative stress in kidney cells. Data have shown that tyrosol, a weak antioxidant monophenolic compound, specifically counteracts Intercellular Adhesion Molecule 1 (ICAM-1) increased expression induced by homocysteine in endothelial cells.
Recent studies indicate that tyrosol (Tyr) and hydroxytyrosol (HTyr), present in extra virgin olive oil, confer cardioprotection through various mechanisms of action including antioxidant, anti-inflammatory, and metabolic regulatory properties. The gut microbiota modulates the structure, bioavailability, and bioactivity of these phenolic compounds, thereby influencing their therapeutic potential.
Following absorption, tyrosol in wine is converted into hydroxytyrosol via different isoforms of cytochrome P450. In a randomized clinical trial in individuals at cardiovascular risk, supplementation of wine with tyrosol resulted in endogenous bioactivation of tyrosol into hydroxytyrosol and in cardioprotective effects including improved endothelial function and increased HDL cholesterol.
In cell studies, tyrosol salvaged myocyte loss, inhibited nuclear condensation and caspase-3 activity dose-dependently, indicating protection against ischemia/reperfusion (I/R)-caused myocyte loss. Furthermore, tyrosol significantly inhibited ROS accumulation and activation of ERK and JNK, augmenting Hsp70 expression. Hsp70 acts as a molecular chaperone and plays a pivotal role in maintaining and repairing cellular homeostasis under thermal, I/R, and oxidative stress. Numerous pieces of evidence have proved that overexpression of Hsp70 builds cardiac resistance to I/R injury.
Tyrosol, along with salidroside, reduced TNF-α-induced adhesion between monocytes and endothelial cells and abrogated TNF-α-induced expression of adhesion molecules VCAM-1 and ICAM-1, as well as production of MCP-1 with inhibition of phosphorylated MAP kinases. TNF-α-mediated NF-κB transactivation and RelA/p65 acetylation were suppressed through interaction of NF-κB with sirtuin-1 (SIRT1), an NAD+-dependent histone deacetylase.
Tyrosol demonstrates antioxidant, anti-inflammatory, and modulatory effects on liver metabolism that may improve chronic liver diseases such as dysfunction-associated steatotic liver disease (MASLD) and liver fibrosis. Mechanistic studies suggest these hepatoprotective effects are exerted through the regulation of multiple cellular pathways, including those involved in antioxidant response and lipid metabolism. In vitro and in vivo studies have suggested these effects occur through the regulation of cellular pathways involved in antioxidant response, lipid metabolism, transcription factor activity, and NF-κB signaling.
Tyrosol exhibits antidiabetic, antiobesity, and hepatoprotective effects via modulation of lipid metabolism, insulin sensitivity, adipogenesis, and gut microbiota.
Tyrosol offers robust neuroprotection against ischemic and neurodegenerative insults. A mixture of olive oil phenols including tyrosol studied in SK-N-SH cells treated with hydrogen peroxide showed that the combination of compounds improved cell viability and decreased ROS.
Tyrosol shows tumor-specific toxicity by inhibiting cell proliferation, inducing cell cycle arrest, and modulating cancer pathways. These effects are largely characterized from preclinical (cell culture and animal) studies; clinical evidence in humans is not yet established.
Human/Clinical Evidence: The most direct human evidence for tyrosol's individual cardiovascular effects comes from a randomized controlled trial by Pérez-Mañá et al. (2019). A randomized, crossover, controlled study design was used. Individuals at cardiovascular risk (n = 33) received white wine (WW) (females 1, males 2 standard drinks/day), WW plus tyrosol capsules (WW + Tyr) at 25 mg per standard drink, and water as control. Participants were classified by a polygenic activity score as low versus normal activity metabolizers. Tyrosol, and its partial biotransformation into hydroxytyrosol, promoted cardiovascular health-related benefits in humans after dietary doses of tyrosol.
A further study from the same group evaluated lipid effects. The purpose was to evaluate the effects of co-administration of white wine and tyrosol on circulating levels of ceramides and other lipids in humans at high CVD risk. Volunteers underwent a randomized controlled crossover clinical trial (4-week duration per intervention) with three interventions: control, white wine, and white wine enriched with a capsule of tyrosol (WW + TYR). It was found that the WW + TYR intervention resulted in lower levels of three ceramide ratios associated with an improvement of endothelial function (Cer C16:0/Cer C24:0, Cer C18:0/Cer C24:0, and Cer C24:1/Cer C24:0), when compared to the control intervention.
The ability of tyrosol to bind human LDL has been reported. Human bioavailability of tyrosol from virgin olive oil in its natural form has been demonstrated, with urinary tyrosol increasing and reaching a peak at 0–4 hours after virgin olive oil administration.
Evidence Strength: There is limited direct human evidence focused exclusively on tyrosol in isolation; the available randomized controlled trials are small (n = 33), involve co-administration with wine (an alcohol-containing matrix), and are short-term. Broader cardiovascular benefits of the Mediterranean diet and olive oil phenolics as a class are supported by much larger epidemiological and intervention evidence, but attributing specific effects to tyrosol alone remains challenging.
The European Food Safety Authority (EFSA) approved health claims regarding the antioxidant properties of virgin olive oil containing at least 5 mg of hydroxytyrosol and its related compounds (tyrosol and oleuropein) per 20 g. This EFSA claim encompasses tyrosol as part of a combination of olive phenolics rather than as a standalone compound.
Bioavailability studies in humans show that the absorption of olive oil phenols is probably larger than 55–66 mol%, and that at least 5% is excreted in urine as tyrosol and hydroxytyrosol. It has been estimated that 50 g of olive oil per day provides about 2 mg or approximately 13 μmol of hydroxytyrosol-equivalents per day, and that the plasma concentration of olive oil phenols with antioxidant potential resulting from such an intake can be at most 0.06 μmol/L. This is much lower than the minimum concentrations (50–100 μmol/L) required to show antioxidant activity in vitro. Although phenols from olive oil seem to be well absorbed, the content of olive oil phenols with antioxidant potential in the Mediterranean diet is probably too low to produce a measurable effect on LDL oxidizability or other oxidative markers in plasma.
Evidence Strength: The direct antioxidant power of tyrosol in isolation is characterized as weak compared to hydroxytyrosol. A well-recognized disconnect exists between in vitro antioxidant assay results and physiological plasma concentrations achievable through dietary intake. Much of the cellular antioxidant evidence is in vitro. The EFSA health claim applies to a mixture of olive phenolics, not tyrosol alone.
Phenolic compounds rosavin, rosarin, rosin, salidroside, and tyrosol are responsible for the biological action of R. rosea, exerting antioxidant, immunomodulatory, anti-aging, and anti-fatigue activities. R. rosea extract formulations are used as alternative remedies to enhance mental and cognitive functions and to protect the central nervous system and heart during stress.
Evidence from cell culture studies demonstrates tyrosol and related compounds reduce oxidative damage and inflammatory signaling in neuronal models, but no randomized controlled human clinical trials have specifically examined isolated tyrosol for neuroprotective or cognitive outcomes. Recent studies indicate that R. rosea may be used to treat diabetes, cancer, and a variety of cardiovascular and neurological disorders such as Alzheimer's and Parkinson's diseases, though these statements are based on preclinical and preliminary data, and tyrosol's specific role within these effects has not been isolated in human trials.
Evidence Strength: Neuroprotective evidence for tyrosol specifically remains largely preclinical (in vitro cell culture and animal models). Human clinical trials on Rhodiola rosea extracts — which contain tyrosol — show positive effects on stress and fatigue, but the individual contribution of tyrosol versus other constituents (rosavins, salidroside) cannot be distinguished from these studies.
Reviews exploring the hepatoprotective properties of tyrosol from extra virgin olive oil indicate both antioxidant, anti-inflammatory, and lipid metabolism-modulating effects, which may mitigate chronic liver diseases such as metabolic-associated liver dysfunction, liver fibrosis, and hepatocellular carcinoma. These compounds demonstrate modulatory effects on liver metabolism that may improve dysfunction-associated steatotic liver disease (MASLD) and liver fibrosis, and their progression to liver cancer. Mechanistic studies have suggested these hepatoprotective effects are exerted through the regulation of multiple cellular pathways, including those involved in the antioxidant response and lipid metabolism.
Evidence Strength: Hepatoprotective evidence derives primarily from in vitro and animal studies with mechanistic data. No dedicated human clinical trials specifically testing isolated tyrosol for liver outcomes have been identified.
In laboratory studies, tyrosol reduced TNF-α-induced adhesion between monocytes and endothelial cells, and abrogated TNF-α-induced expression of adhesion molecules VCAM-1 and ICAM-1, and production of MCP-1, with inhibition of phosphorylated MAP kinases. These effects are mechanistically relevant to atherosclerosis prevention.
Research explores the intricate interactions between tyrosol, hydroxytyrosol, and gut microbiota within the context of atherosclerosis prevention and management. Gut microbial metabolism may magnify or alter the biological effects of tyrosol and hydroxytyrosol, and interindividual differences in microbiota composition may influence their efficacy. A deeper understanding of these mechanisms could support the development of precision nutrition strategies aimed at reducing the risk of atherosclerosis.
Evidence Strength: The anti-inflammatory evidence specific to tyrosol in isolation is predominantly in vitro and from animal models. Human evidence comes from multi-compound interventions with olive oil or wine where the anti-inflammatory effect cannot be attributed solely to tyrosol.
As a constituent of Rhodiola rosea extracts, tyrosol contributes to a body of clinical evidence on that plant. An exploratory single-arm, multi-center study investigated clinical outcomes of R. rosea intervention (200 mg of R. rosea extract) in 118 burnout patients. The fatigue symptoms experienced by the patients continuously declined during the 8 weeks of intervention, with noteworthy results after only one week of treatment and statistically significant improvement at week 8. An open-label, multicenter, single-arm trial explored clinical outcomes in burnout patients treated with 400 mg of R. rosea extract over 12 weeks. A wide range of outcome measures including alertness, calmness, and good mood clearly improved over time, with considerable changes already detected after the first week of administration.
On a molecular basis, the main active ingredients of R. rosea appear to be tyrosol and its glucoside salidroside. When consuming the root, other structurally related bioactive constituents (the rosavins) may also play a role.
Evidence Strength: Human clinical evidence for adaptogenic and anti-fatigue effects is based on R. rosea extract as a whole, not on isolated tyrosol. The contribution of tyrosol specifically cannot be disaggregated from these clinical trials.
Tyrosol shows tumor-specific toxicity by inhibiting cell proliferation, inducing cell cycle arrest, and modulating cancer pathways. Tyrosol and related phenolic compounds are considered promising with significant antioxidant, anti-inflammatory, anticancer, and cardiovascular protective properties, holding considerable potential for the prevention and treatment of chronic diseases including cardiovascular conditions, neurodegenerative diseases, and cancer.
Evidence Strength: Anticancer evidence for tyrosol is currently confined to preclinical in vitro and animal studies. No clinical trials have investigated isolated tyrosol for cancer prevention or treatment in humans.
Tyrosol exhibits antidiabetic, antiobesity, and hepatoprotective effects via modulation of lipid metabolism, insulin sensitivity, adipogenesis, and gut microbiota. These effects have been characterized in cell culture and animal studies. Human evidence in this area is indirect, arising from epidemiological data on the Mediterranean diet and olive oil consumption.
Evidence Strength: Metabolic and antidiabetic evidence is largely preclinical. No human randomized trials specifically on isolated tyrosol for glycemic or metabolic outcomes have been identified.
Tyrosol exhibits various biological activities including antimicrobial, anticarcinogenic, anti-inflammatory, and antioxidant capabilities, making it valuable for potential applications in food, cosmetics, and pharmaceuticals.
Evidence Strength: Antimicrobial evidence for tyrosol is in vitro in nature. No human clinical trials have assessed tyrosol's antimicrobial activity in vivo.
Through antioxidant, anti-inflammatory, and gene-regulatory functions, tyrosol contributes to respiratory protection, ameliorates ulcerative colitis, improves reproductive health, and enhances stress resilience. These claims are based on preclinical evidence.
Evidence Strength: All evidence for these additional systemic effects is preclinical (animal or cell-culture based). Human evidence is absent for these specific indications.
Tyrosol's relatively low toxicity and high bioavailability further underscore its potential as a nutraceutical compound. Bioavailability studies in humans show that the absorption of olive oil phenols is probably larger than 55–66 mol%, and that at least 5% is excreted in urine as tyrosol and hydroxytyrosol.
Human bioavailability of tyrosol from virgin olive oil in its natural form has been demonstrated. Urinary tyrosol increases, reaching a peak at 0–4 hours after virgin olive oil administration.
A critical aspect of tyrosol metabolism is its in vivo conversion to hydroxytyrosol. CYP2D6 and CYP2A6 convert tyrosol into hydroxytyrosol in human liver microsomes, working cooperatively. The involvement of two CYP isoenzymes in the production of hydroxytyrosol is relevant since to date only a few known substrates of CYP2A6 have been reported. The gene that encodes CYP2A6 is highly polymorphic, resulting in extensive interindividual variation in CYP2A6 enzyme activity and the rate of metabolism of CYP2A6 substrates including tyrosol. The dietary health benefits of tyrosol-containing foods remain to be evaluated in light of CYP pharmacogenetics.
Challenges such as low solubility and instability of tyrosol in vivo lead to a shortened biological half-life, decreased bioavailability, and limited applications in some formulation contexts. Thermal oxidation of extra virgin olive oils at 170–220°C causes a significant decrease in hydroxytyrosol- and tyrosol-like substances. This is relevant for food processing and cooking contexts.
Fifteen percent of an oleuropein-glycoside supplement administered to healthy human subjects was excreted in urine as hydroxytyrosol and tyrosol, indicating tyrosol is also a metabolic product of oleuropein-derived compounds.
No established therapeutic or supplemental dosing recommendation for isolated tyrosol has been issued by regulatory agencies. The following doses are those specifically reported in the peer-reviewed literature:
Tyrosol has relatively low toxicity and high bioavailability. Formal dedicated safety assessments for isolated tyrosol supplements have not been published by regulatory bodies such as EFSA or the FDA in the same systematic manner as for hydroxytyrosol. The safety context for tyrosol largely derives from its occurrence in foods that have been consumed for millennia (olive oil, wine).
For the structurally related compound hydroxytyrosol — tyrosol's primary in vivo conversion product — no toxic effects were demonstrated at doses up to 300 mg/kg/day of a virgin olive oil extract rich in hydroxytyrosol, in acute single dose, subacute 14-day supplementation at a maximum dose of 2000 mg/kg/day, and after sub-chronic supplementation during 90 days at up to 1000 mg/kg/day, in accordance with OECD-408 guidelines.
EFSA approved health claims regarding the antioxidant properties of virgin olive oil containing at least 5 mg of hydroxytyrosol and its related compounds (tyrosol and oleuropein) per 20 g of oil. This regulatory recognition implies a favorable safety-to-benefit profile at dietary exposure levels. However, this claim covers tyrosol as part of a mixture, not as an isolated supplement.
A pharmacogenetically relevant safety consideration is the CYP-mediated conversion of tyrosol to hydroxytyrosol. The gene encoding CYP2A6 is highly polymorphic, resulting in extensive interindividual variation in CYP2A6 enzyme activity and the rate of metabolism of CYP2A6 substrates including tyrosol. The dietary health benefits of tyrosol-containing foods remain to be evaluated in light of CYP pharmacogenetics. This implies that individuals who are poor metabolizers of CYP2A6 or CYP2D6 may convert less tyrosol to hydroxytyrosol, potentially altering the magnitude of cardiovascular benefit. Conversely, high metabolizer individuals may generate more hydroxytyrosol.
The dietary phenol tyrosol, found in red wine, olives, and olive oil, is metabolized to hydroxytyrosol by CYP2A6, with minor contributions of CYP2D6 and CYP3A4. Because tyrosol is a substrate of CYP2A6 and CYP2D6, co-administration with potent inhibitors of these enzymes (e.g., certain antidepressants that inhibit CYP2D6, or specific CYP2A6 inhibitors) could theoretically alter tyrosol metabolism and its conversion to hydroxytyrosol, though specific human drug–interaction studies focused on tyrosol have not been identified in the current literature.
Thermal oxidation of extra virgin olive oils at 170–220°C causes a significant decrease in hydroxytyrosol- and tyrosol-like substances. Cooking at high temperatures substantially reduces the tyrosol content of olive oil.
Challenges remain, particularly regarding the low bioavailability of tyrosol in certain formulations, which limits clinical effectiveness. The evidence available concludes that these phenolic compounds have great pharmacological potential; however, further studies are still required. The majority of mechanistic evidence for tyrosol's health benefits derives from cell culture and animal experiments. The number of human randomized controlled trials examining isolated tyrosol as the sole intervention remains small, and most are short-term and conducted in specific populations (e.g., high cardiovascular risk). Conclusions about efficacy cannot yet be reliably extrapolated to the general population or to long-term outcomes.
Health conditions that Tyrosol may help support.
Body systems that Tyrosol may help support.
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