Olive Leaf Extract

• Cardiovascular support
• Blood pressure regulation
• Antioxidant protection
• Blood glucose regulation

• Antimicrobial activity
• Immune support
• Neuroprotection
• Anti-inflammatory effects
• Skin health
• Joint health
• Weight management support

Olive leaf extract (OLE) exerts its diverse biological effects through multiple mechanisms involving various bioactive compounds, with oleuropein being the primary active constituent. Other important compounds include hydroxytyrosol, tyrosol, caffeic acid, p-coumaric acid, verbascoside, luteolin, rutin, and other polyphenols that contribute to olive leaf’s health benefits. One of olive leaf extract’s primary mechanisms is its potent antioxidant activity. The polyphenols in OLE, particularly oleuropein and hydroxytyrosol, neutralize free radicals and reactive oxygen species (ROS) through direct scavenging activity.

These compounds can donate hydrogen atoms to neutralize free radicals, breaking the chain reaction of oxidative damage. Beyond direct antioxidant effects, OLE upregulates endogenous antioxidant systems by activating nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that regulates the expression of antioxidant enzymes like superoxide dismutase (SOD), catalase, and glutathione peroxidase. This dual approach to oxidative stress—direct scavenging plus enhancement of cellular defenses—provides comprehensive protection against oxidative damage to lipids, proteins, and DNA. In the cardiovascular system, OLE demonstrates multiple beneficial mechanisms.

It inhibits angiotensin-converting enzyme (ACE), which helps reduce blood pressure by preventing the conversion of angiotensin I to the potent vasoconstrictor angiotensin II. This ACE inhibition also reduces aldosterone production, potentially decreasing sodium and water retention. Additionally, OLE enhances nitric oxide (NO) production and bioavailability in vascular endothelial cells, promoting vasodilation and improving blood flow. The extract also demonstrates calcium channel blocking activity, which contributes to its antihypertensive effects by reducing vascular smooth muscle contraction.

For lipid metabolism, OLE inhibits LDL oxidation, a critical step in atherosclerosis development. The polyphenols in olive leaf, particularly oleuropein and hydroxytyrosol, prevent the oxidative modification of LDL cholesterol, reducing its atherogenicity. Some research suggests OLE may also modulate the expression of genes involved in lipid metabolism, potentially reducing triglyceride and total cholesterol levels while increasing HDL cholesterol. In glucose metabolism, OLE improves insulin sensitivity through several mechanisms.

It enhances glucose uptake in peripheral tissues by increasing the expression and translocation of glucose transporters (particularly GLUT4). The extract also protects pancreatic β-cells from oxidative damage and may stimulate insulin secretion. Additionally, OLE inhibits the activity of digestive enzymes like α-amylase and α-glucosidase, potentially reducing carbohydrate digestion and postprandial glucose spikes. The anti-inflammatory effects of OLE involve inhibition of pro-inflammatory enzymes like cyclooxygenase (COX) and 5-lipoxygenase, reducing the production of inflammatory mediators such as prostaglandins and leukotrienes.

OLE also suppresses the activation of nuclear factor-kappa B (NF-κB), a key transcription factor in inflammatory responses, thereby reducing the expression of pro-inflammatory cytokines like tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Olive leaf extract demonstrates broad-spectrum antimicrobial activity against bacteria, viruses, fungi, and parasites. For bacterial pathogens, OLE disrupts cell membranes, interferes with protein synthesis, and inhibits bacterial enzymes. Against viruses, it may prevent viral attachment to host cells, inhibit viral replication, and interfere with viral assembly.

The extract’s antifungal effects involve disruption of fungal cell membranes and inhibition of germination and mycelial growth. In the nervous system, OLE exhibits neuroprotective effects through multiple mechanisms. It reduces oxidative stress in neural tissues, inhibits the aggregation of amyloid-beta peptides associated with Alzheimer’s disease, and modulates neurotransmitter systems. Some research suggests OLE may enhance brain-derived neurotrophic factor (BDNF) levels, supporting neuronal health and plasticity.

For immune function, OLE demonstrates immunomodulatory effects, enhancing certain aspects of immune function while reducing excessive inflammation. It may increase natural killer cell activity, modulate cytokine production, and enhance macrophage function. In skin health, OLE’s antioxidant and anti-inflammatory properties help protect against UV damage and photoaging. The extract may also inhibit matrix metalloproteinases (MMPs) that degrade collagen and elastin, potentially preserving skin structure and elasticity.

Through these diverse and complementary mechanisms—antioxidant protection, vascular function enhancement, metabolic regulation, anti-inflammatory effects, antimicrobial activity, and tissue protection—olive leaf extract influences numerous physiological processes, explaining its wide range of traditional uses and the growing body of scientific evidence supporting its various health benefits.

No official Recommended Dietary Allowance (RDA) has been established for olive leaf extract, as it is not considered an essential nutrient. Based on clinical research, effective doses typically range from 500-1,000 mg per day of olive leaf extract, standardized to contain 15-20% oleuropein (providing approximately 75-200 mg of oleuropein daily). The optimal dose may vary depending on the specific health goal, the standardization of the extract, and individual factors such as body weight, health status, and sensitivity to botanical extracts. For general antioxidant support and preventive health benefits, lower doses (500 mg daily) are often sufficient.

For specific therapeutic applications like blood pressure or blood glucose management, higher doses (750-1,000 mg daily) may be more appropriate. Some clinical studies have used doses up to 1,600 mg daily for specific conditions, though such high doses are not typically necessary for general health support. The quality and standardization of the extract significantly impact effective dosing, with properly standardized extracts (typically 15-20% oleuropein) showing efficacy at lower doses than unstandardized products. When using whole olive leaf powder rather than standardized extract, higher doses are typically required (1,000-1,500 mg daily) due to the lower concentration of active compounds.

The bioavailability of olive leaf extract’s active compounds varies significantly based on several factors, including the specific compounds, extraction method, formulation, and individual physiological differences. Oleuropein, the primary active compound, shows moderate oral bioavailability, with significant metabolism occurring during absorption. After oral consumption, oleuropein undergoes partial hydrolysis in the acidic environment of the stomach and further metabolism by intestinal enzymes and gut microbiota. This metabolism converts oleuropein to smaller, more bioavailable metabolites, including hydroxytyrosol, which has high bioavailability and potent biological activity.

Pharmacokinetic studies indicate that oleuropein and its metabolites reach peak plasma concentrations approximately 1-2 hours after ingestion, with a relatively short half-life of 2-4 hours in the bloodstream. However, the compounds may accumulate in tissues with repeated dosing, potentially extending their biological effects beyond what would be predicted from plasma concentrations alone. The bioavailability of olive leaf polyphenols is enhanced by certain formulation factors. Liquid extracts typically show faster absorption than solid forms like capsules or tablets.

Taking olive leaf extract with a small amount of fat (such as olive oil) may enhance the absorption of some of its less water-soluble components. The presence of other compounds in the extract can also influence bioavailability, with some evidence suggesting that the complex mixture of polyphenols in whole olive leaf extract may have synergistic effects on absorption and activity compared to isolated compounds.

Taking with a small amount of healthy fat (like olive oil) may enhance absorption of less water-soluble components, Liquid extracts or tinctures may offer faster absorption compared to capsules or tablets, Standardized extracts with higher oleuropein content provide more consistent bioavailability, Consuming with a meal containing some fat may improve absorption, Liposomal formulations may potentially enhance absorption (though commercial availability is limited), Micronized powder forms may improve dissolution and absorption, Combining with a small amount of black pepper extract (piperine) may theoretically enhance absorption through inhibition of certain metabolizing enzymes, Phytosome formulations (phospholipid complexes) may improve bioavailability of certain compounds, Fermented olive leaf preparations may enhance bioavailability through partial breakdown of complex compounds, Avoiding consumption with high-tannin beverages (strong tea, coffee) that might bind to certain compounds

For general health support, olive leaf extract can be taken at any time of day, though consistency in daily supplementation is more important than specific timing for many of its benefits. Taking olive leaf extract with meals is generally recommended, as the presence of food, particularly foods containing some fat, may enhance the absorption of certain active compounds. This approach may also reduce the potential for mild digestive discomfort that some individuals experience when taking olive leaf extract on an empty stomach. For those using olive leaf extract specifically for blood pressure management, some research suggests that taking it in the morning may align with natural circadian patterns of blood pressure regulation.

However, clinical studies showing blood pressure benefits have typically not controlled for time of day, suggesting that consistent use is more important than timing. When using olive leaf extract for blood glucose management, taking it 15-30 minutes before meals may theoretically provide better effects on postprandial glucose levels, as some of its active compounds can inhibit digestive enzymes involved in carbohydrate breakdown. However, this timing approach is based on mechanism of action rather than specific clinical evidence. For immune support, particularly during periods of increased susceptibility, dividing the daily dose into two administrations (morning and evening) may provide more consistent immune support throughout the day.

This approach is often recommended for herbs with antimicrobial properties, though specific research on timing for olive leaf is limited. When using olive leaf extract alongside medications, it’s generally advisable to separate the doses by at least 2 hours to reduce the potential for interactions, particularly with medications that have a narrow therapeutic window. This is a precautionary approach rather than based on documented interactions. For those taking multiple supplements, olive leaf extract can generally be taken alongside most other supplements without significant interaction concerns.

However, separating it from iron supplements by at least 2 hours may be advisable, as the polyphenols in olive leaf might slightly reduce iron absorption. For topical applications of olive leaf extract (in skincare products), applying to clean skin and allowing sufficient time for absorption before applying other products is recommended. Evening application may provide longer contact time during sleep, though morning application is also appropriate depending on the specific product formulation. Consistency in daily supplementation is generally more important than specific timing for many of olive leaf extract’s benefits, particularly for cardiovascular, metabolic, and antioxidant effects, which typically develop through cumulative action over several weeks of regular use.

• Generally well-tolerated with minimal reported side effects at recommended doses
• Mild digestive discomfort (stomach upset, nausea, or diarrhea)
• Headache (uncommon)
• Dizziness (rare)
• Mild allergic reactions in sensitive individuals (rare)
• Temporary increase in intestinal gas or bloating
• Mild throat irritation (primarily with liquid extracts)
• Potential for mild detoxification reactions when first starting (headache, fatigue, or skin eruptions)
• Temporary changes in taste perception (rare)
• Mild diuretic effect in some individuals

• Known allergy to olive or olive products
• Pregnancy and breastfeeding (insufficient safety data; traditionally avoided)
• Scheduled surgery (discontinue 2 weeks before due to potential effects on blood pressure and blood glucose)
• Caution advised in patients with low blood pressure (hypotension)
• Caution in patients with diabetes who are on medication (may enhance hypoglycemic effects)
• Caution in patients with bleeding disorders or on anticoagulant therapy (theoretical concern based on in vitro antiplatelet effects)
• Caution in patients with autoimmune conditions (theoretical concern due to immune-modulating properties)
• Children under 12 years (limited research in pediatric populations)

• Antihypertensive medications (potential additive effects on blood pressure reduction)
• Diabetes medications (may enhance blood glucose-lowering effects)
• Anticoagulant and antiplatelet drugs (theoretical mild additive effect on bleeding risk)
• Cholesterol-lowering medications (potential additive effects)
• Immunosuppressants (theoretical interaction due to immune-modulating effects)
• Diuretics (potential additive diuretic effects)
• Medications metabolized by cytochrome P450 enzymes (potential interaction, though clinical significance unclear)
• Medications with narrow therapeutic windows (general caution advised due to limited interaction data)

No official Tolerable Upper Intake Level (UL) has been established for olive leaf extract. Based on available research, doses up to 1,600 mg per day of standardized extract have been used in clinical studies without significant adverse effects. However, higher doses may increase the risk of side effects, particularly digestive discomfort, without necessarily providing additional benefits. For most healthy adults, olive leaf extract supplementation within the typical range of 500-1,000 mg daily is unlikely to cause significant adverse effects, even with long-term use.

As with any supplement, it’s prudent to use the lowest effective dose for the intended purpose, particularly for long-term use. Those with specific health conditions, on medications, or with known sensitivities should consult healthcare providers before using olive leaf supplements. A note on hypotensive effects: While olive leaf extract’s blood pressure-lowering effects are generally considered beneficial, they could potentially cause problems for individuals with already low blood pressure or those taking multiple blood pressure-lowering medications. Monitoring blood pressure when first starting olive leaf extract is advisable for these populations.

A note on hypoglycemic effects: Similarly, olive leaf extract’s blood glucose-lowering effects could potentially enhance the effects of diabetes medications, potentially leading to hypoglycemia. Blood glucose monitoring is advisable when combining olive leaf extract with diabetes medications.

In the United States, olive leaf extract is regulated as a dietary supplement under the Dietary Supplement Health and Education Act (DSHEA) of 1994. Under DSHEA, manufacturers are responsible for determining that their products are safe before marketing, but do not need FDA approval. The FDA has not approved specific health claims for olive leaf extract supplements. Manufacturers must limit their claims to structure/function statements (how the product affects the structure or function of the body) rather than disease claims (preventing, treating, or curing specific diseases).

For example, claims about supporting cardiovascular health or healthy blood pressure are permitted, but claims about treating hypertension or heart disease would not be allowed. Olive leaf is included in the FDA’s Generally Recognized as Safe (GRAS) database for certain food uses, particularly as a flavor component. This GRAS status applies to specific applications rather than all uses. The FDA does not routinely test dietary supplements for safety or efficacy before they reach the market, but can take action against unsafe products or those making illegal disease claims.

Eu: In the European Union, olive leaf extract is regulated under the Traditional Herbal Medicinal Products Directive (THMPD) in some member states, allowing traditional use registrations based on historical use rather than clinical trials. In other contexts, it may be regulated as a food supplement under the Food Supplements Directive (2002/46/EC). The European Food Safety Authority (EFSA) has evaluated several health claims for olive products, including olive leaf. While many claims have been rejected due to insufficient evidence meeting EFSA’s stringent standards, olive polyphenols have received approval for claims related to protecting blood lipids from oxidative damage, though this applies primarily to olive oil rather than leaf extract. Regulatory status varies somewhat between EU member states, with some countries having more permissive regulations for traditional herbal products than others.

Australia: The Australian Therapeutic Goods Administration (TGA) regulates olive leaf extract as a listed complementary medicine ingredient. Olive leaf products can be listed on the Australian Register of Therapeutic Goods (ARTG) after meeting safety, quality, and efficacy requirements. The TGA has specific guidelines regarding permitted indications for listed complementary medicines containing olive leaf. In Australia, olive leaf extract has gained significant popularity and is widely available in various formulations.

Canada: Health Canada has approved olive leaf extract as a Natural Health Product (NHP) ingredient with authorized claims related to its role as an antioxidant and for traditional use in herbal medicine. Olive leaf products with approved Natural Product Numbers (NPNs) can be legally sold in Canada with specific authorized claims. Health Canada has established specific quality requirements and dosage recommendations for olive leaf products.

Japan: In Japan, olive leaf extract may be regulated as a non-pharmaceutical health food or as an ingredient in Foods with Function Claims (FFC), depending on the specific product and claims. It is not typically approved as a Kampo medicine (traditional Japanese herbal medicine) as it is not part of the traditional Japanese pharmacopoeia.

Mediterranean Countries: In Mediterranean countries with long traditions of olive cultivation and use (such as Spain, Italy, Greece, and Turkey), olive leaf has special cultural and regulatory status. In these countries, olive leaf remedies are often recognized in traditional pharmacopoeias and may have more extensive approved traditional uses than in other regions. Some of these countries have specific monographs for olive leaf in their national pharmacopoeias.

Low to moderate

$0.20-$0.80 per day for standardized extracts (500-1,000 mg); $0.10-$0.30 per day for leaf powder (higher doses required); $0.50-$1.20 per day for premium or specialized formulations

Olive leaf extract offers good value compared to many other supplements, providing multiple evidence-based benefits at a relatively modest cost. Standardized olive leaf extracts typically cost $0.20-$0.60 per day for standard doses (500-1,000 mg), making them moderately priced compared to many other supplements. The value proposition improves when considering olive leaf’s diverse benefits for cardiovascular health, blood glucose regulation, and antioxidant protection – potentially replacing multiple other supplements for these purposes. For cardiovascular support, comparing olive leaf extract to other options is informative.

At approximately $0.40 per day, olive leaf extract is typically less expensive than many specialized cardiovascular supplements like CoQ10 ($0.50-$2.00 per day), specialized fish oil formulations ($0.80-$2.00 per day), or proprietary heart health blends ($1.00-$3.00 per day). Clinical research suggests olive leaf extract may provide blood pressure benefits comparable to some first-line antihypertensive medications but at a fraction of the cost, particularly for those without insurance coverage for prescriptions. For blood glucose management, olive leaf extract ($0.20-$0.60 per day) compares favorably to many specialized blood sugar supplements ($0.80-$2.00 per day) in terms of cost, though individual responses may vary. The research supporting olive leaf’s benefits for insulin sensitivity and glucose metabolism is growing but still less extensive than for some other supplements like berberine or alpha-lipoic acid.

When comparing products, the standardization of active compounds significantly impacts value. Products standardized to contain 15-20% oleuropein generally provide better value than those with lower standardization or unstandardized products, even if they cost slightly more. This is because the oleuropein content is primarily responsible for many of olive leaf’s health benefits. The specific extract used also affects value.

Extracts with clinical research supporting their efficacy (particularly EFLA®943 used in several studies) may command higher prices but often provide more reliable results. For those seeking to maximize value, olive leaf powder is the most economical option at $0.10-$0.30 per day, though higher doses (1,000-1,500 mg) are required compared to extracts, and the concentration of active compounds may vary. The powder also has a bitter taste that many find unpleasant. For specific therapeutic applications, such as blood pressure or blood glucose management, the value should also consider potential cost savings from reduced need for other interventions or medications.

In these cases, higher-quality extracts with research-backed standardization may offer better overall value despite higher upfront costs. When used for immune support, olive leaf extract ($0.20-$0.60 per day) is comparable in cost to many other immune-supporting supplements like echinacea or elderberry, though the specific benefits and mechanisms differ.

Olive leaf extract stability varies based on the specific preparation method, formulation, and storage conditions. Dried olive leaf extract powder typically maintains its potency for 2-3 years when properly stored in sealed containers protected from light, heat, and moisture. The stability is primarily limited by the potential degradation of polyphenolic compounds, particularly oleuropein, through oxidation and exposure to environmental factors. Standardized extracts in capsule or tablet form generally have a manufacturer-assigned shelf life of 2-3 years, though this is often conservative and the actual stability may be longer.

Liquid extracts and tinctures typically have shorter shelf lives (1-2 years unopened, 6-12 months after opening) compared to dry forms, particularly after opening. The primary degradation pathway for oleuropein and other olive polyphenols is oxidation, which can be accelerated by exposure to light, heat, and oxygen. Some manufacturers add natural antioxidants like vitamin E or rosemary extract to enhance stability, particularly in liquid formulations. Properly standardized and packaged commercial products typically include stability testing to ensure the labeled oleuropein content remains within acceptable ranges throughout the stated shelf life.

Store in a cool, dry place away from direct light and heat (below 25°C/77°F). Keep containers tightly closed to prevent moisture absorption and oxygen exposure, as these can accelerate degradation of active compounds. While refrigeration is not necessary for most olive leaf products, it may extend shelf life, particularly for liquid extracts after opening. Avoid storing in bathrooms or other high-humidity areas.

For olive leaf powder, using the included scoop or a clean, dry utensil is recommended to prevent introducing moisture into the container. Some manufacturers include desiccant packets in olive leaf extract containers to maintain dryness – these should be left in place but not consumed. Once opened, olive leaf powder should ideally be used within 6-12 months for optimal potency, though it may remain stable longer if properly stored. For capsules and tablets, storage in the original container is recommended as these are designed to protect from light and moisture.

Liquid extracts and tinctures should be tightly sealed after use and may benefit from refrigeration after opening. If transferring to another container, ensure it is airtight, opaque, and include a desiccant if possible. Avoid exposure to metal containers or utensils for extended periods, as some metals (particularly iron and copper) can catalyze oxidation reactions of polyphenols.

Oxidation (primary degradation pathway for oleuropein and other polyphenols), Light exposure (particularly UV light, can accelerate oxidation reactions), Heat (accelerates degradation reactions; significant degradation occurs above 40°C/104°F), Moisture (promotes hydrolysis of active compounds and potential microbial growth), Oxygen exposure (leads to oxidation of phenolic compounds), Microbial contamination (if moisture is introduced), Enzymatic degradation (particularly in improperly processed material), Extreme pH conditions (oleuropein is most stable at slightly acidic to neutral pH), Metal ions (particularly iron and copper, can catalyze oxidation reactions), Repeated freeze-thaw cycles (for liquid formulations)

Synthesis Methods

Natural Sources

Quality Considerations

Olive leaf has a rich history of traditional medicinal use spanning thousands of years across Mediterranean and Middle Eastern cultures. The earliest documented medicinal use of olive leaf appears in ancient Egypt, where it was used as a symbol of heavenly power and was utilized in the mummification process. Archaeological evidence suggests that olive leaves were used medicinally in Egypt as early as 3000 BCE. In ancient Greece, olive leaves were widely used for medicinal purposes.

Hippocrates, often referred to as the ‘father of medicine’ (circa 400 BCE), prescribed olive leaf tea as a remedy for various ailments, particularly for treating fevers and malaria. The leaves were also used topically for wound healing and skin conditions. Dioscorides, a Greek physician in the 1st century CE, documented olive leaf’s medicinal properties in his work ‘De Materia Medica,’ noting its astringent, antiseptic, and fever-reducing properties. In ancient Rome, olive leaves were similarly valued for their medicinal properties.

Pliny the Elder, in his ‘Natural History’ (77 CE), described olive leaf preparations for treating fever, wounds, and various infections. The Romans also used olive leaf extracts topically for skin conditions and to promote wound healing. In traditional Arabic and Islamic medicine, olive leaf was highly regarded and mentioned in religious texts. The Quran refers to the olive tree as a ‘blessed tree,’ and olive leaf remedies were incorporated into Islamic medical practices from the 7th century onward.

Avicenna (Ibn Sina), the influential Persian physician of the 11th century, included olive leaf in his ‘Canon of Medicine’ for treating fever, skin conditions, and infections. Throughout the Mediterranean region, traditional folk medicine employed olive leaf for numerous applications. In Spain, Italy, Greece, and North Africa, olive leaf tea was a common household remedy for reducing fevers, treating coughs and colds, lowering blood pressure, and improving digestion. The leaves were also used topically in poultices for skin infections, wounds, and inflammatory skin conditions.

In the 19th century, olive leaf tea gained attention in European medical practice as a treatment for malaria. In 1854, the Pharmaceutical Journal published a report on the use of olive leaf extract as an effective remedy for malaria, noting its ability to reduce fever and fight the infection. This application was particularly significant in regions where malaria was endemic and quinine was scarce or expensive. The modern scientific investigation of olive leaf began in earnest in the early 20th century.

In the 1920s and 1930s, researchers began isolating and identifying the active compounds in olive leaf, though oleuropein, the primary active constituent, wasn’t fully characterized until 1960 by P. Pannizzi and colleagues. In the mid-20th century, olive leaf extract was studied for its antimicrobial properties, with research demonstrating effectiveness against various bacteria, viruses, and fungi. These studies provided scientific validation for many of the traditional uses of olive leaf for treating infections.

The late 20th and early 21st centuries saw a significant increase in research on olive leaf’s cardiovascular benefits, particularly its effects on blood pressure, cholesterol levels, and vascular health. This research has provided scientific support for traditional uses related to heart health and has expanded understanding of olive leaf’s mechanisms of action. Today, olive leaf extract is widely used as a dietary supplement, particularly for cardiovascular health, immune support, and antioxidant protection. Modern standardized extracts typically contain specified levels of oleuropein and other bioactive compounds, providing more consistent potency than traditional preparations like olive leaf tea.

The historical journey of olive leaf from ancient remedy to modern supplement reflects the enduring value of this medicinal plant across cultures and time periods, with contemporary research continuing to validate and expand upon traditional knowledge.

Olive leaf extract for cognitive function in older adults with mild cognitive impairment, Combination of olive leaf extract with standard therapy for metabolic syndrome, Olive leaf extract for non-alcoholic fatty liver disease (NAFLD), Effects of olive leaf extract on endothelial function and arterial stiffness, Olive leaf extract for inflammatory bowel conditions, Topical olive leaf extract for dermatological conditions, Olive leaf extract for upper respiratory tract infections, Long-term safety and efficacy of olive leaf extract for hypertension management, Olive leaf extract’s effects on gut microbiome composition and function, Comparison of different olive leaf extracts and standardization methods for cardiovascular outcomes