Olive Leaf
Olive leaf comes from the olive tree, Olea europaea, and is used fresh or dried, as tea, powder or extract. It is distinct from olives and olive oil.
Also listed as Green Olive, Oleae Folium, Olive Fruit, Olive Pulp
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
What does olive leaf mean here?
Olive leaf comes from Olea europaea. EMA’s traditional herbal assessment covers fresh or dried leaves, tea preparations and powdered leaves. This profile concerns leaves, not olives or olive oil. 1
Why is it used for water retention?
EMA recognizes traditional use to increase water elimination in mild water retention after a doctor has excluded serious causes. That conclusion rests on longstanding use and is distinct from clinical research on blood-pressure extracts. 1 2
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Does the research mean I can replace blood-pressure medicine?
No. The newer trial enrolled people already receiving hypertension treatment and tested the extract as an addition. 2
Is olive-leaf tea the same as the tested extract?
The EMA monograph covers leaves and powdered leaves; the blood-pressure trial studied an extract. These preparations should not be treated as interchangeable evidence. 2 3
Is traditional use proof of a clinical effect?
EMA’s water-retention indication relies on longstanding use. It is a different basis of evidence from a placebo-controlled trial. 1
Sources
- Oleae folium European Medicines Agency
- European Union herbal monograph on Olea europaea L., folium European Medicines Agency, 2017