Olive Leaf Extract and Blood Pressure: A Research Review

What the evidence shows

Human trials suggest a possible short-term lowering of systolic blood pressure, especially in adults with elevated blood pressure, but the finding is not uniform.
A 12-study meta-analysis found average reductions in blood pressure, while a newer review emphasized the small and variable evidence base.
The strongest direct trial evidence is still short-term and does not establish reductions in cardiovascular events or long-term safety.
Olive extracts vary in composition, and mixed leaf-plus-fruit products cannot isolate the effect of olive leaf.
The studied populations were mainly adults with prehypertension or hypertension, so evidence for other groups remains limited.

Bottom line

Olive leaf extract has shown a recurring but not uniform association with lower blood pressure in short human trials. A systematic review of randomized studies found an average reduction in systolic blood pressure, especially among participants with hypertension, while a newer review reached a more cautious conclusion because it included only three eligible studies and found important variation between trials. [1] [2]

The most defensible conclusion is that the evidence shows a plausible short-term signal, not a settled or consistent effect across all adults. The research has measured blood-pressure changes, not reductions in cardiovascular events or proof of long-term benefit.

Who has been studied

The available research has focused mainly on adults with elevated blood pressure rather than healthy people with consistently normal readings. Study populations have included people described as prehypertensive, people with stage-1 or mild-to-moderate hypertension, and adults already receiving care for hypertension. [1] [2] [3]

The populations were not uniform:

One crossover trial studied 60 prehypertensive men with a mean age of about 45 years. [4]
A newer multicenter trial enrolled 621 adults with hypertension who were already being treated for the condition. [3]
A 2026 trial enrolled 56 adults with systolic blood pressure of at least 130 mmHg, but tested a mixed olive product containing both leaf and fruit extracts. [5]

This leaves limited direct evidence for children, pregnancy, people with consistently normal blood pressure, and long-term use in diverse older populations.

What pooled analyses found

A 2022 systematic review and meta-analysis included 12 studies involving 819 participants. Six studies, representing 372 participants, contributed systolic blood-pressure data. The pooled estimate was a reduction of 3.86 mmHg in systolic pressure. In a subgroup of participants with hypertension, the estimated reductions were 4.81 mmHg for systolic pressure and 2.45 mmHg for diastolic pressure. [1]

Those findings are informative but should not be treated as a guaranteed individual response. The review combined different extracts, study populations, comparison groups, and follow-up periods. It rated the certainty of evidence for blood pressure as moderate, while also identifying studies with some concerns or high risk of bias.

A 2025 systematic review included only three eligible studies involving 248 analyzed participants. It found a pre-intervention to post-intervention reduction in systolic pressure, but the studies were heterogeneous and the pooled diastolic result was less certain. Its larger estimate in a higher-intervention subgroup came from a small evidence base and does not establish a general dose-response pattern. [2]

Representative trial results

The individual trials illustrate why the overall conclusion remains cautious. In the 2017 randomized, double-blind crossover study, 60 prehypertensive men used a phenolic-rich olive leaf extract and a control intervention in separate six-week periods. Twenty-four-hour systolic pressure was about 3.33 mmHg lower and 24-hour diastolic pressure about 2.42 mmHg lower during the extract period relative to control. [4]

The larger 2025 multicenter randomized, double-blind, placebo-controlled trial included 621 adults and followed them for 12 weeks. It reported a reduction in 24-hour systolic pressure and improvements in several secondary measures, including blood-pressure load. No significant adverse events were reported during that trial, but its duration was still short relative to the time frame relevant to chronic blood-pressure outcomes. [3]

In contrast, the 2026 randomized placebo-controlled trial of a standardized olive extract found that systolic pressure fell in both groups, with no statistically significant difference between them. Because the product combined olive leaf and olive fruit extracts, the trial also cannot isolate the contribution of olive leaf. [5]

How strong are the study designs

Several studies used useful methods: random allocation, blinding, placebo or control groups, and repeated blood-pressure measurements. Ambulatory 24-hour monitoring, used in some trials, can provide a more stable outcome than a single office reading. The crossover design used in the 2017 study also allowed participants to serve as their own comparison, although that design depends on an adequate washout period. [3] [4]

The main weaknesses are small samples in many trials, short follow-up, different extract compositions, and inconsistent comparator conditions. Some older evidence also came from open or active-control designs, which are more vulnerable to expectancy and measurement bias than a well-controlled placebo trial. The pooled literature therefore gives a direction of effect but not a highly standardized estimate that can be assumed to apply across products or populations. [1] [2]

What remains uncertain

The research has not established whether olive leaf extract produces a durable blood-pressure change beyond roughly two to twelve weeks, or whether any observed change translates into fewer cardiovascular events. No trial cited here establishes an effect on heart attacks, strokes, cardiovascular mortality, or other long-term outcomes.

Important unanswered questions include:

Whether standardized oleuropein content predicts the blood-pressure response.
Whether results differ between untreated participants and those already using blood-pressure medication.
Whether the effect is present in women, older adults, and people without elevated blood pressure.
How much results are influenced by regression to the mean, background lifestyle changes, or placebo response.
Whether short-term tolerability findings adequately describe longer-term safety or product-specific interactions.

These uncertainties matter because olive leaf extracts are not chemically identical. Results from one standardized preparation cannot automatically be transferred to every capsule, tea, or blended olive product.

Overall research verdict

Human research supports a possible modest short-term reduction in blood pressure, with the clearest signal appearing in adults who already have elevated readings. The evidence includes randomized and blinded trials, including one relatively large multicenter study, but it also includes small studies, heterogeneous preparations, and at least one recent null comparison.

The fairest summary is that olive leaf extract is promising but not consistently established for blood-pressure change. Future research should use clearly characterized leaf-only preparations, independent funding where possible, larger samples, longer follow-up, ambulatory blood-pressure outcomes, and prespecified analyses of medication use and participant subgroups.

Sources

About this article

NootroWorld publishes research summaries, not medical advice. This article describes what studies have and have not established; it does not tell you what to take. Supplements can interact with medication, pregnancy and existing health conditions, and study populations often differ from your own situation. Discuss any personal decision with a qualified healthcare professional.