Also known as: Olea europaea, Oleuropein, Hydroxytyrosol, Olive polyphenols
BotanicalGood evidence
An extract of olive leaves standardised to oleuropein, with reasonable evidence for blood pressure and vascular measures. The leaf contains far more polyphenol than the oil does.
Typical dose
500.0–1000.0 mg per day
With food, split across the day
What it is
Olive leaf extract comes from the leaves of Olea europaea rather than the fruit or the oil. The leaves are a by-product of olive cultivation and pruning.
The compound of interest is oleuropein, the bitter phenolic that gives olives their harshness before curing. Leaves contain considerably more of it than the fruit, and far more than olive oil, where most is lost in processing.
Extracts are standardised to oleuropein content, commonly 15 to 25 per cent. Some also declare hydroxytyrosol, a related and highly bioavailable compound that oleuropein breaks down into.
How it works
Oleuropein and its metabolites have antioxidant activity and influence endothelial function, supporting the ability of blood vessels to widen. That is the main proposed route to the blood pressure findings.
There is also reported activity on enzymes involved in blood pressure regulation, and effects on inflammatory signalling.
Oleuropein is extensively metabolised, with hydroxytyrosol being the more bioavailable end product. That is one reason some products now standardise to both rather than oleuropein alone.
What the evidence shows
Blood pressure is the best-supported outcome. Several controlled trials and meta-analyses have reported modest reductions, more evident in people with elevated readings than in those already normal.
There is reasonable evidence for improvements in lipid markers, and work on blood sugar handling with modest findings.
The wider claims made for it, particularly around immunity, rest largely on laboratory work rather than human trials. It is a decent cardiovascular polyphenol sold with a good deal of unsupported additional framing.
Dosing
Typical range is 500 to 1,000 mg of extract daily, often split across two servings. Trials on blood pressure have generally used doses in this band over 6 to 12 weeks.
Dose against oleuropein content rather than extract weight, since standardisation varies considerably between products.
Take with food. Effects on blood pressure accrue over weeks rather than acutely, so give it a couple of months before judging. It combines sensibly with other vascular ingredients since the mechanisms differ.
Metabolites clear within hours; blood pressure effects accrue over weeks
Timing
With food, split across the day
Competition status
Permitted — not on the WADA Prohibited List
Category
Botanical
Safety and side effects
Olive leaf extract is well tolerated. Digestive upset and headache are the most commonly reported effects and are generally mild.
Because it lowers blood pressure, take care if yours is already being managed, and be aware of the possibility of it dropping further than intended.
It may also lower blood sugar and has a mild effect on how readily blood clots. Speak to your doctor before use if you take regular medication, and stop before scheduled surgery.
Who should avoid it
Take care if your blood pressure or blood sugar is being managed, and speak to your doctor first in either case. Speak to your doctor before use if you take anything affecting blood clotting or any regular medication. Stop before scheduled surgery. Avoid if sensitive to olives. Not established in pregnancy or breastfeeding.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
