Evidence: High Possible Benefits: Very High Safety: High
TABLE OF CONTENTS
What is olive leaf extract?
Olive leaf extract is an extract made from the leaves of the olive tree. This extract is often used as a supplement for improving blood pressure and cholesterol levels but can also have various other beneficial effects. This article is about the main benefits of an olive leaf extract, its potential side effects, the best time to take it, and more.
Possible benefits
All of the potential benefits mentioned below are dose-dependent. As with other adaptogens, there is a sweet-spot dose that allows you to get most of the benefits without causing meaningful side effects or tolerance buildup in the body. We will discuss the best dosing protocol later in this article.
Major benefits
Lowered blood pressure – Olive leaf extract can be extremely helpful for reducing blood pressure. It is comparable in potency with some blood pressure medications, such as Captopril. This benefit only applies to people with elevated blood pressure and should not make your blood pressure drop too low.
Improved cholesterol levels – The supplement was shown in multiple studies to reduce LDL and increase HDL cholesterol levels. The reduction in LDL is more reliable than the increase in HDL. Both of these changes are rather small in magnitude. However, the biggest benefit of olive leaf extract in regard to cholesterol is that it can significantly and reliably reduce the oxidation of LDL. Even low doses can reduce LDL oxidation rates by over 25%.
Reduced DNA damage – One study noted up to 50% reductions in mitochondrial and urine measurements of DNA damage.
Increased healthspan and lifespan – Besides the positive effects of olive leaf extract on blood pressure, cholesterol levels, DNA damage, and other things associated with general health, this supplement was also shown to support stem cell differentiation, immune signaling, autophagy, and anti-senescence mechanisms. It also influences NF-κB, mTOR, and AMPK signaling in a positive way. All of these things suggest that this extract can increase both healthspan and lifespan.
Minor benefits
Antioxidant properties – Olive leaf extract can induce the activity of glutathione peroxidase and other antioxidant enzymes. The supplement can also reduce oxidative parameters in the blood.
Reduced blood glucose – Olive leaf extract can significantly improve blood glucose levels in diabetics and people with insulin resistance. A small decrease in HbA1c and insulin (both fasted and postprandial) has also been found. The healthier your blood glucose levels are, the less of an effect olive leaf will have.
Improved insulin sensitivity – Unlike a reduction in blood glucose, this effect applies to healthy people as well.
Improved brain function – While olive leaf extract is rarely seen as a nootropic, many of its mechanisms in the body can directly support brain health and cognition. For example, the supplement can support neural autophagy, neuroprotection, brain ATP levels, and neural mitochondrial function. Animal studies found improvements in spatial working memory (in old mice) and overall improved cognitive function.
Possible side effects
The side effects below are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.
Initial adverse reaction – When you start taking olive leaf extract, things can get worse before they get better. This extract can temporarily worsen some aspects of your health and even make you sick for a few days after you start taking it. That can be unpleasant, but it is usually a sign that the supplement is working and creating a hormetic response that allows the body to adapt and become more resilient in the long term.
Allergic reaction – Some people are allergic to olives or the olive leaf and may experience an allergic reaction after they start taking it. Unlike the “initial adverse reaction,” allergic reactions typically don’t disappear until one stops taking the supplement.
Nausea – This side effect is most common when people take the extract on an empty stomach.
Diarrhea – You can usually prevent diarrhea or stomach discomfort by taking this extract with a meal.
Toxicity – As an adaptogen, olive leaf extract acts as a mild stressor on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, stressing the body too much can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking high amounts of this extract could lead to chronic toxicity and cause health problems over time. To prevent chronic toxicity or the buildup of tolerance, staying below 1000 mg of an average extract or 140 mg of oleuropein daily is best unless you have a great reason to take more.
Contamination – If growing or storing conditions are not adequately controlled, olive leaves can be contaminated with bacteria, molds, and other potentially harmful microorganisms. Some growers also use pesticides and herbicides that can be unsafe. Another issue is that herbal supplements can get contaminated with other supplements and chemicals during the manufacturing process. Choose the brand you get herbs and herbal supplements from wisely. It is often best to use websites like Amazon, where thousands of users have reviewed and rated the products. You are less likely to buy something of lower quality there.
Who should not take olive leaf extract?
You should probably avoid taking olive leaf extract if you:
are allergic to olives
experience a severe adverse reaction after taking the extract (though a mild adverse reaction is usually a great thing as it is a sign that the supplement is working and causing a hormetic response that allows the body to adapt and become more resilient)
are pregnant or breastfeeding (while it can be safe to take this adaptogen during pregnancy or breastfeeding, it acts as a mild stressor and can put some unnecessary risk to the child)
Who will benefit the most?
You should consider taking the supplement if you:
have high cholesterol levels
have high blood pressure
are a diabetic
wish to improve healthspan and lifespan
are an older person and want to improve cognitive health
have a high budget for supplements and are willing to experiment with a variety of them (assuming you don’t fall into any of the categories that should avoid this supplement, olive leaf extract appears safe and is unlikely to do more harm than good for most people)
How much olive leaf extract should you take?
Olive leaf extract can be considered an adaptogen. It acts as a mild hormetic stressor on the body, which allows your body to adapt and become more resilient to certain kinds of stressors in the long term.
A higher dose does not necessarily lead to more pronounced benefits. Instead, there appears to be an inverted U-shaped dose-response pattern. In other words, you want to find a sweet-spot dose that allows you to get the benefits of olive leaves without putting too much pressure on the body or quickly causing the body to develop tolerance to the extract.
Doses as low as 10 mg can reduce the oxidation of LDL and lead to a few other benefits. These doses can be obtained from olive oil. However, higher doses can certainly provide more benefits.
The sweet-spot dose for an average olive oil extract ranges anywhere between 500-1000 mg daily. If you purchase an extract standardized for oleuropein, the sweet-spot dose of oleuropein is about 50-140 mg.
The higher end of this range usually provides slightly more benefits in the short term. If you plan to take this extract for a longer time (multiple months or years), the lower end is probably a better way to go since you would develop tolerance faster if you were to take higher doses.
Additionally, very high doses can put too much pressure on your system and cause health problems if you take the supplement for a prolonged period.
While olive leaf could theoretically cause acute toxicity, you’d need to take an extremely high dose that would be way beyond what even the most potent supplements contain.
Like most other adaptogens, it is best to cycle olive leaf extract and take about two days off weekly to reset your tolerance. That will allow you to keep getting the benefits in the long term.
Keep in mind that the effects of this extract are cumulative. Therefore, you must take it for at least 2-4 weeks to notice most of the benefits. But again, cycling the extract and not taking it at least twice a week is necessary to prevent tolerance in the long term.
Best time to take olive leaf extract
You can take this extract with or without food. Each of these options has its benefits. Oleuropein and most of the other bioactive compounds in the olive leaf are water-soluble and should absorb well either way.
If you experience nausea or stomach discomfort when you take this extract, taking it with food should prevent these unpleasant effects or at least make them less intense.
If you take this extract on an empty stomach, the short-term effects will kick in faster, and they will be more pronounced but will not last as long.
Whether you take this extract in the morning or the evening typically does not make much difference. Both options are fine so feel free to experiment.
Where to buy olive leaf extract?
In most countries, Amazon is the best option for ordering olive leaf extract and other plant extracts and supplements. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.
Some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.
FAQ
As with most other plants and plant extracts, it is best to cycle olive leaf extract and take a break from it for about two days per week to reset your tolerance back to baseline. That will keep your body sensitive to the extract and allow you to keep getting the benefits in the long term.
When you take an extract standardized for oleuropein, you know exactly how potent it is and how much you need to take to get the desired outcome. Herbal extracts also tend to be cheaper than unextracted powders in many cases. However, many of the potentially beneficial compounds get lost during the extraction process. Therefore, if you know how potent the unextracted powder is, it is almost always a better option.
All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes time which can add up over months or years. The disadvantage of capsules is that they are often made of bovine gelatine, which rarely comes from ethical sources.
Yes, you can. This supplement should not impact your sleep in any negative way. Whether you take it in the morning or the evening typically doesn’t make much difference. Both options are fine so feel free to experiment.
This extract should not become harmful once it exceeds the expiration date, but it can lose potency over time. Keep this supplement in a cold, dark, and dry place and it should remain just as potent for many months or even years.
As an adaptogen, olive leaf extract acts as a mild stressor on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, putting too much pressure on the body can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking very high amounts of this herb could lead to chronic toxicity and cause health problems over time. High doses can also make you develop tolerance much faster than lower doses so they may be less effective in the long term.
While you could safely take higher doses, there is usually no point in taking more than 1000 mg of an average extract or 140 mg of oleuropein daily. This amount should give you most of the benefits without meaningful side effects. Paradoxically, taking a higher dose would likely lead to fewer benefits as the body would quickly become accustomed to the herb.
Unfortunately, there is not much information about the half-life of olive leaf extract in the body. From what we know, oleuropein has a half-life of at least 12 hours. However, most of the effects of this herb are cumulative, so they mostly happen in the long term rather than acutely. Therefore, the half-life of this herb isn’t very relevant in practice.
The effects of this extract are cumulative. Therefore, you must take it for at least 2-4 weeks to notice most of the benefits. But again, cycling the herb and not taking it at least twice a week is necessary to prevent tolerance in the long term.
Yes, olive leaf extracts are vegan-friendly. If you buy this herb in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.
No, it does not. The supplement does not interfere with fasting in any significant way.
References
Most of the information in this guide is based on scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything you read in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.
