Olive leaf extract (OLE) is a product of the olive tree leaves which is rich in phenolic compounds that researchers around the world found to have beneficial effects upon human health. The compounds, one of which is oleuropein, have great anti-inflammatory, antioxidant, anti-hypertension, cardioprotective, obesity protective, and immune stimulative effects

The olive tree or Olea europaea L. mostly grows and it is cultivated in the Mediterranean countries i.e. Spain, Italy, Portugal, and Greece which grow 98% of the world olive tree cultivation. However, there are other countries that grow olive trees, such as the  Arabian Peninsula countries, India, and Asia.

The main product of the olive trees, to be more precise form the olive fruit itself, is the olive oil. The global production of olive oil is about 11 million tons per year and these countries consume it the most.

Actually, olive oil is one of the basic ingredients in the Mediterranian diet which is considered to be one of the healthiest in the world.

The olive oil is considered to be healthy because it is rich with many phenolic compounds that affect health in the most positive way.

However, the olive leaves also contain phenolic compounds like oleuropein, hydroxytyrosol, verbascoside, and many others which can be found in even higher doses than in the olive oil.

When we talk about olive leaves we think about leaves and branches trimmed from the olive trees when the olives are harvested.


The chemical configuration of OLE depends on many factors and that’s why we should be careful when using products from different companies.

The quality of OLE depends on the origin, storage condition of the branches and the leaves, the weather conditions, and the soil contamination. Professional pharmaceutical industries take care of these factors and pick up the best goods.

They are also careful about the process of drying and extraction of the OLE. There are studies that show the difference between drying with freezing and drying with hot air (with a temperature higher than 120°C.

It turned out the best way to preserve the anti-inflammatory and antioxidant potential of the OLE, compared to the fresh olive leaves, is the hot air drying because it provides higher phenolic content, especially the substance called oleuropein.

The most important ingredients in the olive leaf extract

We have already mentioned that the Mediterranean diet is one of the healthiest in the world. It is like that because it is rich with olive oil which, in addition, is rich with polyphenols, a kind of chemical that brings benefits to our health.

The extra virgin olive is rich with these substances.

However, it is more interesting that the olive leaves contain an even higher amount of these substances.

For instance, the amount of oleuropein in olive oil ranges from 0.005%-0.12%, whereas it ranges from 1-14% in olive leaves. The difference is enormous.

Because of this data, it is clear that the olive leaves carry a bigger potential to contribute to a healthier diet and treatment of some illnesses.

Oleuropein is not the only compound that is extracted from the olive leaves.

Other phenolic compounds are also very important.  Those are verbascoside, flavones, flavonols, and substituted phenols.

All of these in combination with the oleuropein give the most prominent effects on people’s health.

Olive leaf extract against inflammation 

Inflammation is a very common health issue that is usually accompanied by pain. There are numerous traditional pain and anti-inflammatory drugs that are commonly used,  but doctors are also content when a natural ingredient can help in relieving these conditions.

There are studies that show that oleuropein in OLE has pharmaceutical features. It has been proven that it has great anti-inflammatory, analgesic, and sedative effects which helps in many health problems accompanied by pain and inflammation.

In this study, it is clearly shown that It affects the downregulation of substances that trigger inflammation in the body, and that way helps the reduction of inflammation-related states.

Olive leaf extract helps arthritis 

Arthritis, a common name for rheumatoid arthritis (RA) or osteoarthritis, is another inflammatory condition. It stands for inflammation of the joints in the body. It is a painful condition where one or several joints can hurt a lot at the same time.

Some studies show that the olive leaf extract (OLE) can be combined with the standard therapy of RA and can give excellent results.

To be more specific, when OLE is combined with the standard therapy in the early stages of RA, the levels of DNA damage in the cells and the proinflammatory substance were significantly reduced. It means that the inflammation was improved and the disease activity was suppressed.

The same effect was not that strong in patients with long-term RA, but the combined administration gave better results than the standard therapy only.

This is just another effect of the olive leaf extract on an additional inflammatory disease – arthritis, which is proven to be really painful and bothersome.

Olive leaf extract in chronic colitis

Chronic colitis intestinal inflammation known as inflammatory bowel disease (IBD) characterized by a chronic inflammatory process involving the gastrointestinal (GI) tract. There are many studies that show that OLE or oleuropein, to be more precise, can be very beneficial for patients with this disease.

Giner and collaborators showed that oral supplements of oleuropein through diet can significantly reduce chronic colitis symptoms.

Namely, oleuropein reduced the recruitment of the inflammatory cells where the injuries on the intestines from the diseases were found. This happened because there was a decreased release of inflammatory substances which actually play the most important role in the development of this disease.

This means that oleuropein was very effective in reducing the symptoms of another inflammatory disease like chronic colitis.

Olive leaf extract against diabetes  

Diabetes, or insulin resistance, belongs to the group of chronic inflammatory diseases. They are considered as one of the most notable causes of death by WHO in the world. WHO assumes that inflammatory diseases will be the biggest human health threat in the future.

As we already talked about the specific features of the oleuropein, which has a high ability to modulate inflammation, we got to the point to see the effect it has on one of the most modern diseases – diabetes. And, of course, the effect it has is very promising and positive. It reduces the damage made by the inflammatory substances, it lowers down the glucose absorption and it increases insulin sensitivity.

The olive leaf extract has a well-known hypoglycemic effect. It functions in two ways: 1) it helps insulin release and 2) increases peripheral glucose uptake.

In a study made with middle-aged overweight men who took the supplementation of OLE for 12 weeks was concluded that their insulin sensitivity was significantly improved compared to the group who took a placebo.

These men were at risk of developing type 2 diabetes and according to the results, OLE can help them a lot to improve their current state.

Olive leaf extract against high blood pressure

Hypertension, or high blood pressure, strikes 50 million people across the US and about 1 billion worldwide. As the world population becomes older, high blood pressure will become a much more common state to be treated.

A study from 2010 evaluated the effect of OLE on systolic blood pressure (SBP) and diastolic blood pressure (DBP) on people with stage 1 hypertension. The study shows that a dose of 1000 mg per day was able to reduce both SBP and DBP.

Another study from 2017 was conducted over 60 males with hypertension in a duration of 6 weeks.

The results show that in males of the experimental group their high blood pressure was significantly lower compared to the control after taking OLE. There was also a significant difference in the level of cholesterol and triglycerides compared to the control group.

This means that OLE has a significant positive effect on the whole cardiovascular system and not just high blood pressure.

Olive leaf extract against obesity

Obesity is frequently referred to as the new disease of modern society. People in developed countries have food available at any time and at any amount. Moreover, most of the food is processed and high on fat and carbohydrates.

Obesity is defined as an energy-balance disorder where the intake of calories exceeds the outflow or their burning because of excessive eating and/ or no physical activities.

There are some studies which show that oleuropein may prevent obesity or rather say achieve an anti-obesity effect. There is a study made of rats that were fed with a high-fat diet (HFD) and were supplemented with oleuropein for ten weeks. It was concluded that the oleuropein significantly reduced the weight gained in the mice fed with HFD.

There was another research also done on mice randomly divided into two groups. The first group of mice was HFD fed and supplemented with OLE, the other group was fed with HFD, but wasn’t receiving OLE for 8 weeks. The research showed that mice that received olive leaf extract reduced the body weight, improved metabolism, and decreased fat tissue.

These studies show that OLE can be used in the process of weight loss or even in the process of not gaining weight at all. However, all the studies are done on mice, and it would take a while to be conducted on people.


The form of OLE and the way how it can be consumed is different. Basically there are 3 ways: as a supplement, in a tea form, and applied externally as a cream or a gel. The most suitable oleuropein dosage and the highest one as well can be found in a supplement form, capsules or pills, and, if applicable, as a tincture.

Tea is great if you use it in the long term i.e. as prevention. The amount of oleuropein in tea is much lower than in the supplements. It can be interchangeably used with green tea. Both of these tea types contain big amounts of antioxidants.

The olive leaf extract cream or the gel is very useful for wounds or irritated skin, as well as some inflammatory conditions of the skin.

Olive leaf extract doesn’t have a daily recommended dosage. The standard dose may be between 500 mg and 1,000 mg per day. You will most often be suggested to split the dose in at least two. One part taking in the morning and the other in the evening. But, you can split the dosage in even more than two and up to four times per day the most.

However, everybody should be aware of the possible side-effects and should consult their doctor for further consumption.

Side Effects

You have read many scientific studies and researches about the effects of olive leaf extract on people, but some of them were done on mice. Not all of the studies have included people, even if they did, there are not many studies conducted on people.

Because of that, not a lot is known about the regular, constant use of the olive leaf extract as a supplement. The dosage may also not be the right one for you so you should be careful when deciding to start using it.

However, there are some reports about the possible side effects of the olive leaf extract. Some of that is that it may trigger mild side effects like headache, muscle discomfort, stomach pain, or even allergy.

Since this is a herbal supplement it may contain pollen from the leaves and branches of the tree and may trigger severe allergic reactions to it. If you have an allergy of any kind it would be wise to check on the chemical list before consuming. Be careful if you are allergic to plants in the family of olive trees (Oleaceae family of plants) like jasmine, forsythia, privet, lilies, and so on.

Food and Drug Administration (FDA) takes this product to be a dietary supplement and it doesn’t monitor the dosage or the quality of the herbs. Because of that, you should be careful when using and definitely consult your doctor about it.

The long-term side effects are also not known because it is a relatively new supplement with no long history. If you experience anything which you consider unusual after taking this product, immediately consult your doctor.

Interaction with other medicines

Olive leaf extract has a significant effect on many health conditions like diabetes, hypertension, or some inflammatory diseases. Because of that, you should be careful if you take the supplement together with other medicines.

For example, if you take standard medications for hypertension prescribed by your doctor and combine it with olive leaf extract, it may happen to lower your blood pressure additionally and cause a sudden drop of pressure which may affect your heart rhythm.

Or, if you are diabetic and take certain prescribed doses of insulin, now, when taking olive leaf extract, you may increase the sensitivity to insulin unintentionally and cause hypoglycemia, which is a very dangerous situation.

It is very important to check if this supplement is suitable for you with your doctor or pharmacist, especially if you already have some of the above-mentioned preconditions.


Olive leaf extract is a dietary product or a food supplement that the scientists have been investigating quite vigorously lately. It is like that because it has been proven that the extract is full of very useful substances called phenolic compounds, one of which is oleuropein – a mighty anti-inflammatory antioxidant, antiobesity, anti-hypertension and cardioprotective substance.

The oleuropein can be found in all olive products, but it is for sure that the amount of oleuropein is the highest in the olive leaves. That is why the leaves are used to produce olive leaf extract.

In many studies, it was proven that the olive leaf extract has the utmost positive effect on human health. It predominantly helps people fight inflammations of any kind. It helps lessen the inflammation and pain in arthritis, rheumatoid arthritis, and osteoarthritis.

It also helps in bowel inflammations like colitis, which is another disturbing health issue for some people. In all of these conditions, olive leaf extract does not only alleviate the symptoms, but it also repairs the damages made in the cells.

Diabetes is another chronic inflammatory disease that has conquered the world. Luckily, science is trying to find a new and natural way to beat these diseases. Olive leaf extract helps the body to increase insulin sensitivity and lower blood sugar.

Hypertension and other cardiovascular diseases are also on the list of olive extract oil. It helps to lower the blood pressure and clear the body of excessive cholesterol.

Finally, obesity! The biggest enemy of the modern man. It is interesting how this extract does not let the fat stay in the body even if it is consumed.

If you ask me, I think that the scientists haven’t discovered the full potential of the olive leaf extract yet. Its time is yet to come, and I am sure there will be much more to be found out.

Comments are closed.