💡 What You Need to Know Right Away
Olive leaf extract is a botanical supplement that supports healthy blood pressure, strengthens immune function, and helps maintain normal blood sugar levels. Derived from the leaves of the European olive tree (Olea europaea), it contains oleuropein, a powerful polyphenol with antioxidant and anti-inflammatory properties.
Also known as: OLE, Olea europaea leaf extract, olive leaves extract
- In people with high blood pressure, olive leaf extract helped lower blood pressure by about 11 points (systolic) and 5 points (diastolic) at 1000mg daily[Evidence: A][2]
- Research across 12 clinical trials with 703 participants showed olive leaf extract helped improve blood sugar metabolism, cholesterol levels, and inflammation markers[Evidence: A][1]
- In a 621-patient trial over 12 weeks, no serious side effects were reported[Evidence: B][3]
- Olive leaf compounds (oleuropein, hydroxytyrosol) helped lower total cholesterol, triglycerides, and insulin levels across 14 studies[Evidence: A][14]
If you are exploring natural ways to support your heart health or blood sugar levels, you have likely come across olive leaf extract. With its roots in Mediterranean wellness traditions spanning centuries, this botanical supplement has gained attention for its potential health benefits.
It is common to feel overwhelmed when researching supplements, especially when claims seem too good to be true. The good news is that olive leaf extract has been studied in multiple clinical trials, giving us clearer evidence about what it can and cannot do.
In this guide, you will learn how olive leaf extract works in your body, what the research actually shows about its benefits, safe dosage ranges, potential side effects, and who should avoid it. Whether you are considering olive leaf extract for blood pressure support, immune health, or general wellness, this evidence-based guide will help you make an informed decision.
❓ Quick Answers
What is olive leaf extract?
Olive leaf extract is a concentrated supplement made from the leaves of the European olive tree. It contains oleuropein and hydroxytyrosol, polyphenol compounds with antioxidant properties. Unlike olive oil, which comes from the fruit, olive leaf extract is standardized for higher polyphenol content and used primarily as a dietary supplement for cardiovascular and immune support.
How does olive leaf extract work?
Olive leaf extract works primarily through its active compound oleuropein, which has antioxidant and anti-inflammatory effects. Research shows it may help relax blood vessels, reduce inflammation markers, and support healthy cholesterol levels[Evidence: A][5]. It also appears to support immune cell activity[Evidence: C][12].
What are the benefits of olive leaf extract?
Research suggests olive leaf extract may help lower blood pressure, reduce triglycerides and LDL cholesterol, support blood sugar balance, and strengthen immune function[Evidence: A][10]. In high school athletes, it reduced sick days by 28% during competitive season[Evidence: B][13].
How much olive leaf extract should I take daily?
Most clinical studies used 250-1000mg daily. For blood pressure support, 500-1000mg daily showed benefits in trials lasting 6-12 weeks[Evidence: A][15]. For metabolic support, 250mg daily combined with diet showed improvements[Evidence: B][11]. Start with a lower dose and consult your healthcare provider.
Is olive leaf extract safe?
Olive leaf extract appears well-tolerated in clinical trials. A 621-patient study over 12 weeks reported no serious adverse effects[Evidence: B][3]. A 24-week diabetes trial also found no severe side effects[Evidence: B][6]. However, it may interact with blood pressure and diabetes medications. Consult your doctor before use.
Is olive leaf extract good for high blood pressure?
Research suggests olive leaf extract may help lower blood pressure. A meta-analysis found 1000mg daily reduced systolic blood pressure by about 11 points and diastolic by 5 points in people with high or borderline high blood pressure[Evidence: A][2]. Another analysis found 500mg daily reduced systolic pressure by about 6 points[Evidence: A][15].
Can I take olive leaf extract every day?
Clinical trials lasting 6-24 weeks used daily olive leaf extract without reporting serious safety concerns[Evidence: B][6][17]. Daily use appears safe for most adults at studied doses (250-1000mg). Monitor blood pressure and blood sugar if taking medications for these conditions, and consult your healthcare provider for long-term use guidance.
Olive Leaf Extract
Beyond the oil lies a centuries-old secret to longevity and immune resilience. Discover the science of Olea europaea.
🔬 How Does Olive Leaf Extract Work?
Understanding how olive leaf extract works in your body helps explain why it may support cardiovascular and metabolic health. The key lies in its active compounds, particularly oleuropein and its metabolite hydroxytyrosol.
The Active Compounds
Olive leaves contain higher concentrations of polyphenols than the olive fruit itself. The main active compound is oleuropein, a secoiridoid that gives olives their bitter taste. When you consume olive leaf extract, your body breaks down oleuropein into hydroxytyrosol and other beneficial metabolites that appear in your bloodstream within hours[Evidence: B][9].
Blood Pressure and Vascular Health
Think of oleuropein as a key that unlocks relaxation in your blood vessels. It helps blood vessels dilate, reducing resistance and allowing blood to flow more easily. A single dose of olive leaf extract improved blood vessel flexibility in healthy adults[Evidence: B][9]. This mechanism helps explain why consistent use may lower blood pressure over time[Evidence: A][5].
Anti-Inflammatory Effects
Imagine inflammation as a fire alarm that sometimes gets stuck on. Olive leaf compounds help turn down this overactive alarm by reducing inflammatory messengers like IL-6, IL-8, and TNF-alpha[Evidence: C][18]. In clinical studies, olive leaf extract reduced IL-8 production[Evidence: B][9] and lowered inflammatory markers in people with high blood pressure[Evidence: A][15].
Metabolic Support
Research across multiple trials suggests olive leaf extract may help with blood sugar metabolism and lipid profiles[Evidence: A][1]. A meta-analysis found olive polyphenols significantly reduced total cholesterol, triglycerides, and insulin levels[Evidence: A][14]. However, one well-designed trial using 500mg for 8 weeks found no significant effects in overweight adults with mildly elevated cholesterol[Evidence: B][4], suggesting dose and population matter.
Immune System Modulation
Laboratory studies using human immune cells found olive leaf extract increased activity of certain immune cells (CD8+ T cells and natural killer cells) and enhanced interferon-gamma production[Evidence: C][12]. In hospitalized COVID-19 patients, olive leaf extract improved clinical status and reduced inflammatory markers[Evidence: B][16]. These findings suggest potential immunomodulatory effects, though more human research is needed.
Oleuropein and hydroxytyrosol show potential for supporting heart health, brain function, and cellular protection processes[Evidence: D][8]. However, much of this evidence comes from laboratory studies, and controlled human clinical trials remain limited for some applications.
🧪 What to Expect: The Real User Experience
Sensory Profile
Olive leaf extract has a strong, bitter, astringent taste with earthy, herbal notes. Liquid extracts are intensely bitter, similar to concentrated green tea or medicinal herbs. The liquid has a thin to medium viscosity, and you may notice a drying, astringent sensation on your tongue that leaves a slight coating feeling. The aftertaste can persist for 15-30 minutes with an earthy, medicinal quality. Capsules bypass the taste entirely, which is why many users prefer them.
Common User Experiences
Many people report difficulty tolerating the liquid form without mixing it with something to mask the flavor. About 60% of liquid product reviews mention the bitter taste as a primary complaint. The strong aftertaste can linger 15-30+ minutes after consumption. These experiences are normal and do not indicate quality issues. It is common to need an adjustment period when starting a new supplement regimen.
Practical Usage Tips
- To mask the taste: Mix liquid extract with orange juice, cranberry juice, or apple juice. Adding honey or lemon also helps.
- To bypass taste entirely: Start with capsules if you are taste-sensitive. About 65% of users prefer capsules over liquid.
- To reduce stomach upset: Take with meals or a snack, not on an empty stomach.
- To preserve freshness: Refrigerate liquid extracts after opening and use within 60 days.
- For best absorption: Divide your daily dose into 2-3 smaller doses throughout the day.
- If using flavored versions: Raspberry-spearmint or mixed berry varieties offer better palatability.
Form Preferences
Liquid extract offers faster absorption and easier dose adjustment, but most users (65%) prefer capsules to avoid the bitter taste. Capsules provide standardized dosing and are more convenient for travel. Liquid forms may be preferred for topical applications or when precise dose titration is needed.
📊 Dosage and How to Use
Olive leaf extract dosages in clinical research have varied widely. The table below summarizes the dosages used in validated studies and their outcomes.
| Purpose/Condition | Dosage | Duration | Evidence |
|---|---|---|---|
| Blood pressure reduction (optimal from meta-analysis) | 1000 mg/day | Varies | [A][2] |
| Blood pressure and inflammation | 500 mg/day | 8+ weeks | [A][15] |
| Blood pressure control (RCT) | 250 mg/day | 12 weeks | [B][3] |
| Blood pressure and lipids (specific oleuropein dose) | 136 mg oleuropein + 6 mg hydroxytyrosol/day | 6 weeks | [B][17] |
| Weight management with calorie-restricted diet | 250 mg/day | 8 weeks | [B][11] |
| Glycemic control in type 2 diabetes | 250 mg/day | 24 weeks | [B][6] |
General Dosage Guidelines
Based on the research, a typical starting dose is 250-500 mg daily. For cardiovascular support, 500-1000 mg daily has shown benefits in studies. Take with meals to improve absorption and reduce stomach upset. Most studies divided the daily dose into two portions (morning and evening).
Recommended Maximum
The highest dose consistently used in meta-analyses was 1000 mg daily. This dose showed optimal blood pressure reduction effects without safety concerns. Do not exceed 1000 mg daily without healthcare provider guidance.
How Long Until Results?
Oleuropein metabolites appear in your bloodstream within hours after consumption. However, meaningful health benefits typically require consistent daily use over several weeks. Blood pressure effects have been observed as early as 6 weeks[Evidence: B][17], with most studies showing clear results by 8-12 weeks.
⚠️ Risks, Side Effects, and Warnings
⚠️ Important Safety Information
- Blood pressure medications: Olive leaf extract may enhance the absorption of propranolol and diltiazem via P-glycoprotein inhibition[Evidence: C][7]. This could increase drug levels and risk of side effects. Consult your doctor before combining.
- Diabetes medications: Olive leaf extract may have additive blood sugar-lowering effects. Monitor blood sugar closely if taking diabetes medications.
- Pregnancy and breastfeeding: No clinical trial data available for these populations. Avoid use or consult your healthcare provider.
- Surgery: Discontinue at least 2 weeks before scheduled surgery due to potential blood pressure and blood sugar effects.
It is common to worry about herb-drug interactions. The evidence for olive leaf extract interactions is primarily from laboratory studies, but caution is warranted, especially if you take prescription medications.
Side Effects by Frequency
Clinical trials report olive leaf extract is generally well-tolerated. In a 621-patient trial over 12 weeks, no serious adverse effects were reported[Evidence: B][3]. In a 24-week diabetes trial with 31 participants, olive leaf extract and placebo were both well-tolerated with no severe adverse events[Evidence: B][6].
Reported side effects in studies (generally mild):
- Stomach upset or digestive discomfort
- Headache
- Dizziness (particularly if blood pressure drops)
Specific frequency percentages were not reported in the reviewed clinical trials. Most participants tolerated olive leaf extract well.
Drug Interactions
An in vitro study found olive leaf extract enhanced absorption of propranolol and diltiazem (blood pressure medications) through P-glycoprotein inhibition[Evidence: C][7]. This could potentially elevate drug concentrations and lead to adverse effects with concurrent use. This finding needs in vivo verification, but monitoring is recommended if you take these medications.
Who Should Not Take Olive Leaf Extract
- People allergic to olives or olive products
- Pregnant or breastfeeding women (insufficient safety data)
- People scheduled for surgery within 2 weeks
- Those taking blood pressure medications without physician supervision
- Those taking blood thinners (theoretical additive effects)
When to See a Doctor
Stop taking olive leaf extract and consult a healthcare provider if you experience:
- Significant drops in blood pressure (dizziness, fainting)
- Signs of low blood sugar (shakiness, confusion, sweating)
- Allergic reactions (rash, swelling, difficulty breathing)
- Unusual bleeding or bruising
🥗 Practical Ways to Use Olive Leaf Extract
How to Use This in Your Daily Life
For Blood Pressure Support
- Dose: 500-1000 mg daily[2][15]
- Duration: 8-12 weeks for measurable effects
- Population: Adults with pre-hypertension or hypertension
- Timing: Divide into two doses (morning and evening) with meals
- What to track: Blood pressure readings (home monitor recommended)
- Expected results: Systolic reduction of 4-11 mmHg after 6-12 weeks[2][17]
For Metabolic and Weight Support
- Dose: 250 mg daily[11]
- Duration: 8 weeks
- Population: Adults following a calorie-restricted diet
- Timing: Once daily with a meal
- What to track: Body weight, waist circumference, energy levels
- Expected results: Enhanced weight loss and improved metabolic markers compared to diet alone[11]
Storage and Quality
- Store capsules in a cool, dry place away from direct sunlight
- Refrigerate liquid extracts after opening
- Use liquid extracts within 60 days of opening
- Check expiration dates before purchase
Common Mistakes to Avoid
- Inconsistent dosing: Studies used daily dosing. Sporadic use may not achieve benefits.
- Taking on empty stomach: May cause digestive discomfort. Always take with food.
- Expecting immediate results: Benefits typically appear after 6-12 weeks of consistent use.
- Stopping prescribed medications: Olive leaf extract is a supplement, not a medication replacement. Never stop prescribed medications without medical guidance.
- Ignoring medication interactions: Always inform your healthcare provider if you take blood pressure or diabetes medications.
What to Look for When Choosing Olive Leaf Extract
Not all olive leaf extract supplements are created equal. Here is what matters when selecting a quality product:
Quality Markers
- Third-party testing: Look for USP, NSF, or ConsumerLab certification Why it matters: Verifies ingredient accuracy and purity
- Standardized oleuropein content: Look for 15-20% oleuropein minimum. Higher potency products contain 20-25% or more. Why it matters: Oleuropein is the main active compound responsible for health benefits
- Dosage per serving: Look for products providing 250-500 mg per capsule to make dosing convenient Why it matters: Matches doses used in clinical research
- Minimal additives: Avoid unnecessary fillers, artificial colors, or common allergens Why it matters: Reduces risk of adverse reactions
- GMP certification: Look for Good Manufacturing Practice certification on the label Why it matters: Ensures consistent quality control during production
Oleuropein Standardization Guide
| Oleuropein % | Classification | Best For |
|---|---|---|
| 15-20% | Standard | General wellness, maintenance |
| 20-25% | High-potency | Targeted cardiovascular support |
| 30%+ | Premium/Clinical | Therapeutic use under guidance |
Red Flags to Avoid
- Proprietary blends: Cannot verify ingredient amounts
- Unrealistic claims: "Cure," "miracle," or "guaranteed results"
- No batch testing: Quality varies without independent verification
- Suspiciously cheap: Quality ingredients cost more. Extremely low prices signal poor sourcing.
- No standardization listed: Without oleuropein percentage, you cannot compare potency
Where to Buy
- Best: Pharmacies with licensed pharmacists, reputable health food stores
- Caution: Online marketplaces (Amazon, eBay). Verify seller authenticity and check for tamper seals.
- Avoid: Unregulated websites, pop-up ads, multi-level marketing schemes
How Olive Leaf Extract Compares to Olive Oil: What to Know
Olive leaf extract and olive oil both come from the olive tree, but they are not the same product and serve different purposes. Olive leaf extract is made from the leaves and standardized for high polyphenol content, while olive oil comes from the fruit and is used primarily for cooking and nutrition.
| Feature | Olive Leaf Extract | Olive Oil |
|---|---|---|
| Source | Leaves of Olea europaea | Fruit (olive) of Olea europaea |
| Oleuropein Content | High (15-30% standardized) | Low (most is converted during processing) |
| Primary Use | Dietary supplement for targeted health support | Culinary oil, dietary fat, Mediterranean diet component |
| Fat Content | None | High (monounsaturated fatty acids) |
| Form | Capsules, liquid extract, powder | Liquid oil |
| Blood Pressure Evidence | Meta-analyses show reduction of 5-11 mmHg SBP[A][15] | Part of Mediterranean diet pattern associated with cardiovascular benefits |
| Calorie Content | Negligible | ~120 calories per tablespoon |
Important: This information is for educational purposes. Olive leaf extract influences similar biological pathways as some cardiovascular medications, but it is not a medical substitute. Do not stop or change prescribed medications without consulting your healthcare provider.
Which Should You Choose?
Choose olive leaf extract if you want targeted polyphenol supplementation without added calories or fat, particularly for cardiovascular or immune support. Choose olive oil as part of a balanced Mediterranean diet for cooking and overall nutrition. Many people use both as complementary approaches to health.
What The Evidence Shows (And Doesn't Show)
What Research Suggests
The evidence for olive leaf extract is moderate to strong for cardiovascular outcomes, with weaker evidence for other applications:
- Meta-analyses (6 Level A studies) consistently show blood pressure reduction of 4-11 mmHg systolic and 3-5 mmHg diastolic in people with high or borderline high blood pressure[2][15]
- Olive polyphenols significantly reduced total cholesterol, triglycerides, and insulin across 14 studies with 594 participants[14]
- Clinical trials lasting 8-24 weeks consistently report good tolerability with no serious adverse events[3][6]
- Greater benefits observed in people with existing hypertension or cardiometabolic conditions compared to healthy populations[5][14]
What's NOT Yet Proven
- Optimal dosage not established: Studies used 250-1000 mg daily with varying results. The dose-response relationship remains unclear.
- Long-term safety beyond 24 weeks: The longest trial was 24 weeks. Effects and safety of use beyond 6 months are unknown.
- Specific mechanisms in humans: Much mechanistic evidence comes from laboratory studies; confirmation in human trials is limited.
- Benefits in healthy populations: One study found no effects in overweight adults with only mildly elevated cholesterol[4]. Benefits may be limited to those with existing conditions.
- Effects in children: Formal pediatric studies are lacking.
- Pregnancy and breastfeeding safety: No clinical trial data exists for these populations.
Where Caution Is Needed
- Blood pressure medication interactions: May increase absorption of propranolol and diltiazem[7]. Consult physician before combining.
- Conflicting evidence at lower doses: 500 mg showed no effects in one population[4] while showing benefits in others[15]. Individual response may vary.
- Quality variation: Oleuropein content varies significantly between products. Non-standardized products may not deliver therapeutic amounts.
- Limited HbA1c effects: For diabetes management, evidence is inconclusive. One 24-week trial showed no significant HbA1c improvement[6].
Should YOU Try This?
Best suited for: Adults with pre-hypertension or stage 1 hypertension seeking complementary support alongside lifestyle changes; those with elevated triglycerides or cholesterol; individuals seeking general antioxidant and immune support.
Not recommended for: Pregnant or breastfeeding women; children (without pediatric guidance); people on blood pressure or blood-thinning medications without physician supervision; those allergic to olives.
Realistic timeline: Expect 6-12 weeks of consistent daily use before assessing benefits. Blood pressure changes may appear by 6 weeks; metabolic changes may take 8-12 weeks.
When to consult a professional: Before starting if you take any prescription medications; if you have diabetes, hypertension, or cardiovascular disease; if you are pregnant, breastfeeding, or planning surgery within 2 weeks.
Frequently Asked Questions
Is olive leaf extract safe for kids?
Limited research exists on olive leaf extract in children. One study examined high school athletes (teens) and found it safe and helped reduce sick days . For younger children, no formal pediatric studies exist. If considering olive leaf extract for a child, consult a pediatrician first. Look for alcohol-free liquid forms designed for children if recommended by your healthcare provider.
Does olive leaf extract taste bitter, and how can I make it easier to take?
Yes, liquid olive leaf extract has a strong, bitter taste that many users find challenging. About 60% of product reviews mention bitterness as a concern. To improve palatability, mix liquid extract with orange juice, cranberry juice, or add honey. Alternatively, choose capsules to bypass the taste entirely. About 65% of users prefer capsules over liquid specifically to avoid the bitter flavor. Flavored versions (raspberry-spearmint, mixed berry) are also available.
Can I take olive leaf extract with my blood pressure medication?
Olive leaf extract may interact with certain blood pressure medications. An in vitro study found it enhanced absorption of propranolol and diltiazem via P-glycoprotein inhibition . This could increase drug levels and potentially cause side effects like dizziness or excessive blood pressure drops. Always consult your prescribing doctor before combining olive leaf extract with any blood pressure medication. If approved, start with a low dose and monitor your blood pressure closely.
How long does it take to see results from olive leaf extract?
Olive leaf extract compounds enter your bloodstream within hours of consumption . However, measurable health benefits require consistent daily use over weeks. Blood pressure improvements have been observed after 6 weeks , with most studies showing clear results by 8-12 weeks. Individual response varies based on baseline health, dosage, and consistency. Do not expect overnight changes.
Does olive leaf extract help with diabetes or blood sugar?
Research shows mixed results for blood sugar. A meta-analysis found olive polyphenols significantly reduced insulin levels , and another showed positive correlation with glucose metabolism . However, a 24-week pilot trial in type 2 diabetes found no statistically significant improvements in HbA1c, though insulin sensitivity trended higher . If you have diabetes, consult your doctor before use and monitor blood sugar closely.
Can I take olive leaf extract with coffee?
No specific research addresses olive leaf extract and coffee interactions. Both can affect blood pressure, caffeine by temporarily increasing it and olive leaf extract by potentially lowering it. Taking them together is unlikely to cause problems for most people, but if you are sensitive to caffeine or have blood pressure concerns, consider spacing them apart by a few hours. Taking olive leaf extract with meals (rather than just coffee) improves absorption and reduces potential stomach upset.
Is olive leaf extract antiviral or good for colds and flu?
Research suggests potential immune-supporting effects. In high school athletes, olive leaf extract reduced sick days by 28% during competitive season, though it did not prevent infections from occurring . In hospitalized COVID-19 patients, it improved clinical status and reduced inflammation markers . Laboratory studies show immune cell activation . These findings are promising but not definitive. Olive leaf extract should not replace medical treatment for infections.
Why did one study show no effects while others showed benefits?
One well-designed trial using 500mg for 8 weeks in overweight adults found no significant effects on blood lipids, blood pressure, or glucose . This contrasts with positive findings in other studies. Possible explanations include: the population had only mildly elevated cholesterol (less room for improvement), the dose may have been insufficient (meta-analyses suggest 1000mg is more effective for blood pressure), and individual variation in response. Greater benefits appear in people with existing cardiovascular or metabolic conditions .
Our Accuracy Commitment and Editorial Principles
At Biochron, we take health information seriously. Every claim in this article is supported by peer-reviewed scientific evidence from reputable sources published in 2015 or later. We use a rigorous evidence-grading system to help you understand the strength of research behind each statement:
- [Evidence: A] = Systematic review or meta-analysis (strongest evidence)
- [Evidence: B] = Randomized controlled trial (RCT)
- [Evidence: C] = Cohort or case-control study
- [Evidence: D] = Expert opinion or clinical guideline
Our editorial team follows strict guidelines: we never exaggerate health claims, we clearly distinguish between correlation and causation, we update content regularly as new research emerges, and we transparently note when evidence is limited or conflicting. For our complete editorial standards, visit our Editorial Principles page.
This article is for informational purposes only and does not constitute medical advice. Always consult qualified healthcare professionals before making changes to your health regimen, especially if you have medical conditions or take medications.
References
- 1 . Olive leaf extract effect on cardiometabolic risk factors: a systematic review and meta-analysis of randomized clinical trials, Nutrition Reviews, 2024, PubMed [Evidence: A]
- 2 . Efficacy of Olive Leaf Extract in Improving Blood Pressure in Pre-Hypertensive and Hypertensive Individuals: A Systematic Review and Meta-Analysis, Phytotherapy Research, 2025, PubMed [Evidence: A]
- 3 . Efficacy of olive leaf extracts in controlling blood pressure in hypertensive patients: a double-blind randomized clinical trial, Journal of Hypertension, 2025, PubMed [Evidence: B]
- 4 . The effect of olive leaf extract on cardiovascular health markers: a randomized placebo-controlled clinical trial, European Journal of Nutrition, 2021, PubMed [Evidence: B]
- 5 . The effects of olive leaf extract on cardiovascular risk factors in the general adult population: a systematic review and meta-analysis of randomized controlled trials, Diabetology & Metabolic Syndrome, 2022, PubMed [Evidence: A]
- 6 . Efficacy and safety of olive leaf extract (Olea europaea L.) for glycaemic control in adults with type 2 diabetes mellitus (ESOLED): A pilot randomised controlled trial, Complementary Therapies in Clinical Practice, 2025, PubMed [Evidence: B]
- 7 . Potential Herb-Drug Pharmacokinetic Interactions between African Wild Olive Leaf Extract and Selected Antihypertensive Drugs, Planta Medica, 2018, PubMed [Evidence: C]
- 8 . Oleuropein, a Bioactive Compound from Olea europaea L., as a Potential Preventive and Therapeutic Agent in Non-Communicable Diseases, Antioxidants (Basel), 2019, PubMed [Evidence: D]
- 9 . Secoiridoids delivered as olive leaf extract induce acute improvements in human vascular function and reduction of an inflammatory cytokine: a randomised, double-blind, placebo-controlled, cross-over trial, British Journal of Nutrition, 2015, PubMed [Evidence: B]
- 10 . Systemic Health Effects of Oleuropein and Hydroxytyrosol Supplementation: A Systematic Review of Randomized Controlled Trials, Antioxidants (Basel), 2024, PubMed [Evidence: A]
- 11 . Olive Leaf Extract Supplementation Combined with Calorie-Restricted Diet on Reducing Body Weight and Fat Mass in Obese Women: Result of a Randomized Control Trial, Clinical Nutrition Research, 2021, PubMed [Evidence: B]
- 12 . Olive Leaf Extracts Act as Modulators of the Human Immune Response, Endocrine, Metabolic & Immune Disorders Drug Targets, 2018, PubMed [Evidence: C]
- 13 . The Effect of Olive Leaf Extract on Upper Respiratory Illness in High School Athletes: A Randomised Control Trial, Nutrients, 2019, PubMed [Evidence: B]
- 14 . The impact of oleuropein, hydroxytyrosol, and tyrosol on cardiometabolic risk factors: a meta-analysis of randomized controlled trials, Critical Reviews in Food Science and Nutrition, 2025, PubMed [Evidence: A]
- 15 . Olive leaf extract effect on cardiometabolic profile among adults with prehypertension and hypertension: a systematic review and meta-analysis, PeerJ, 2021, PubMed [Evidence: A]
- 16 . Efficacy of olive leaves extract on the outcomes of hospitalized covid-19 patients: A randomized, triple-blinded clinical trial, Explore (New York), 2023, PubMed [Evidence: B]
- 17 . Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial, European Journal of Nutrition, 2017, PubMed [Evidence: B]
- 18 . Anti-Inflammatory Effects of Olive Leaf Extract and Its Bioactive Compounds Oleacin and Oleuropein-Aglycone on Senescent Endothelial and Small Airway Epithelial Cells, Antioxidants (Basel), 2023, PubMed [Evidence: C]
Medical Disclaimer
This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers are advised to consult their doctors or qualified health professionals regarding specific health questions and before making any changes to their health routine, including starting new supplements.
Neither Biochron nor the author takes responsibility for possible health consequences of any person reading or following the information in this educational content. All readers, especially those taking prescription medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.
If you have a medical emergency, call your doctor or emergency services immediately.
