Olive Leaf Extract
A regular part of the Mediterranean diet, olives, olive leaf, and olive leaf extract also have a centuries-long history of use in Tunisia, Morocco, Greece and other countries as a traditional, natural treatment for a variety of symptoms and conditions, from high blood pressure to infections to constipation.
The main active ingredient in olive leaf is a polyphenol called oleuropein. Polyphenols are a type of antioxidant, giving them many beneficial medicinal and therapeutic properties, including anti-inflammatory, antimicrobial, antiviral and anti-tumor properties as well as potentially helping to prevent osteoporosis, cancer and cognitive decline.
A secondary polyphenol in OLE is called oleacein. In addition to these, OLE contains an assortment other polyphenolic compound also attributing to those properties, including hydroxytyrosol, tyrosol and caffeic. (Sources: "Effects of the Olive-Derived Polyphenol Oleuropein on Human Health"; International Journal of Molecular Sciences, "Hydroxytyrosol: Health Benefits and Use as Functional Ingredient in Meat"; Medicines)
Whereas the ancient Mediterranean cultures consumed the olive leaves they harvested directly from olive trees as a food, today, you can ingest only the active ingredient from olive leaves extracted into a convenient tincture known as olive leaf extract (OLE). With similar benefits as olive oil, except in a much more concentrated form. In any form it may be, OLE offers an array of health benefits.
Conditions Olive Leaf Extract Benefits
People take olive leaf extract for a wide variety of conditions and symptoms. Many of those uses have even undergone extensive scientific study verifying their benefits. When available, those studies are referenced below.
Weak or Compromised Immune System

Bacteria and Viruses; Olive Leaf Extract Antiviral

According to research and ancient tradition alike, OLE shows great promise for relieving and preventing colds, flus and other chronic illnesses.
In a review of research examining OLE's anti-microbial properties, called "Antimicrobial Efficacy of Olive Leaf Extract Antimicrobial Efficacy of Olive Leaf Extract: A systematic review of in vitro study" and published in 2016 in Advances in Bioresearch, multiple test-tube studies have verified and confirmed the anti-microbial properties of the compound.
Meanwhile, a 2007 review of research entitled "Colds and influenza: a review of diagnosis and conventional, botanical, and nutritional considerations" published in Alternative Medicine Review found that OLE halted the replication of the flu virus in animal studies.
In addition, OLE may help cut down the length and degree of various infections, both chronic and acute, including:
- Upper respiratory infections
- Influenza and the common cold
- Candidiasis
- Shingles
- Urinary tract infections
- Mononucleosis
- Rotavirus
OLE can also help to relieve symptoms related to viral and bacterial illnesses, like diarrhea and chronic fatigue.
High Blood Pressure; Olive Leaf Extract for Blood Pressure
A 2011 study published in Phytomedicine called "Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: Comparison with Captopril", researchers gave subjects with stage 1 hypertension a twice-daily dose of either OLE or the high-blood-pressure medication captopril.
After eight weeks, blood pressure had lowered significantly in both groups, demonstrating that OLE was as effective as captopril in achieving those results.

In a 2017 study published in European Journal of Nutrition called "Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial", researchers gave either OLE or a placebo to 60 subjects with prehypertension for six weeks while monitoring their blood pressure throughout.
From the results, they concluded that OLE may lower both diastolic and systolic blood pressure, as well as cholesterol, triglycerides and inflammatory markers of high blood pressure.
Aging

Joints and Bones

Not exclusively a problem for the aging, issues of joint pain, chronic and otherwise, and conditions like osteoporosis and osteoarthritis may all benefit from OLE.
In a 2017 Nutrients review of research called "Therapeutic Effects of Olive and Its Derivatives on Osteoarthritis: From Bench to Bedside", osteoarthritis patients showed improvements after taking OLE.
The study also speaks to the autophagic property of OLE, which is its ability to clean out damaged cells and replace the area with fresh, newly generated healthy cells.
Type 2 Diabetes

- Cholesterol
- Serum glucose
- Blood glucose and plasma malondialdehyde levels and other indications of oxidative stress, in which an excess of free radicals causes damage to the body’s cells
- Hyperglycemia, or high blood sugar
- Hyperinsulinemia, or excessive insulin in the blood
A human study recounted in the review found that, while taking OLE didn’t significantly affect insulin levels, it may help reduce insulin resistance in the body, one of the main risk factors for the illness.
In the same human study, OLE did, however, lower fasting plasma insulin levels, as well as average blood sugar levels.

Alzheimer’s and Parkinson’s disease

According to a 2014 study published in the International Journal of Molecular Sciences entitled "Effects of the Olive-Derived Polyphenol Oleuropein on Human Health", the antioxidant properties of oleuropein may help protect against Alzheimer’s disease and prevent loss or damage of dopamine neurons related to Parkinson’s disease.
Olive Leaf Extract Herpes

Cancer

- Breast cancer
- Prostate cancer
- Pancreatic cancer
- Colorectal cancer
Cardiovascular Health and Cholesterol

Weight Management
In a similar study, published in Science Direct in 2018 and called, "Evaluation of hypocholesterolemic effect of oleuropein in cholesterol-fed rats", obese rats fed a high-cholesterol diet experienced a reduction in fatty tissue, metabolic profile improvements and lower overall body weight after being administered oleuropein for eight weeks.

While more human studies on OLE for weight loss are still warranted, these studies on rats have at least led researchers to conclude already that OLE can help to prevent unwanted weight gain and, thereby, lower obesity risk.
Olive Leaf Extract Dosage

Once you know that you'd like to try taking OLE, the next questions are: how much to take and where to obtain it?
Olive leaf extract comes in several forms, including:
- Supplement - In which the OLE is dried and powdered and delivered in a tablet, softgel or capsule form
- Tincture - In which the OLE is infused into an alcohol or glycerin
- Tea - In which the OLE is steeped in hot water
While no official dosing recommendations exist, WebMD reports that studies find daily doses of 500-1,000 mg of OLE appropriate.
On the label of many OLE supplements, you’ll read the recommendation to split this dosage into between two and four servings spread out throughout the day and taken with food.

That said, specific dosing most appropriate for men, women or children is not currently available and, for that reason, you should consult with your doctor if you'd like more guidance about precisely how much OLE is right for you. Your doctor can even monitor you while you're taking it to help assess its effects.
OLE for Pregnant Women

There is currently a lack of sufficient data to conclude whether or not OLE is safe or effective for pregnant or breastfeeding women.
Olive Leaf Extract Side Effects

The relatively small amount of research into OLE to date leaves little known about the potential side effects from taking it.
One of the most severe known potential side effects of olive leaf extract is an allergic reaction affecting the respiratory system, particularly in people who are allergic to pollen, and of those, particularly those allergic to the pollen from the Oleaceae family of plants that also includes privets, forsythia, jasmine, lilacs and ash trees. (Source: ”Natural Standard Herb & Supplement Guide - E-Book: An Evidence-Based Reference”; Natural Standard)
Drug Interactions
If you have diabetes or take any blood thinners or blood pressure medications, consult with your doctor before trying OLE. When taking blood pressure medication in particular, olive leaf extract can bring your blood pressure down too low.
Similarly, those taking blood sugar medications or insulin should be cautious using olive leaf extract, as it can bring on hypoglycemia. If you are taking chemotherapy drugs, the antioxidant properties in OLE can interfere with the treatment’s actions.
Also consult with your doctor before taking OLE if you have kidney disease.
While mild, other potential side effects of OLE include:
- Discomfort
- Headaches
- Stomach pains
- Coughing
- Vertigo

While the US Food and Drug Administration (FDA) doesn’t regulate OLE or any other nutritional supplements, its centuries-long history of use by people from thriving Mediterranean cultures may give you some comfort as to its relative safety.
That said, if you experience any concerning or severe side effects while taking OLE, certainly cease taking it until you at least first speak with a doctor.
Where to buy OLE

Keep in mind that supplements are not regulated by the FDA or any other US government body for product safety.
Therefore, for quality assurance when choosing a brand of olive leaf extract supplements, seek out those products manufactured on a SQF certified facility regulated by the FDA
When storing olive leaf extract, keep it in a dark, cool space, like the kitchen cabinet. And keep the capsules store in its original bottle to maximize its lifespan.
You can find OLE for sale in health food stores and online.
Summary

Olive leaf extract has many possible benefits, including some that may help you. Before you try OLE for any conditions or symptoms you experience, let your doctor know what you’re planning first, in case he or she wants to monitor you or check your medical history and medication list for any contraindications.
Beyond that, keep in mind that, as with any herbal therapy, the results from OLE can be subtle, especially at first, and gradual, building up in their efficacy over time.
Don’t consider OLE a possible replacement for any therapies you’re already taking or doing under a doctor’s recommendation, but rather as a supplement, to help it all work better and increase your likelihood of experiencing the results you’re seeking faster and more fully.
