Olive Leaf Extract

Olive leaf is well tolerated and has more cardiovascular research than most herbs on the shelf. Here's the triage our naturopaths run, and most of it is about medicines you might already be on.

A good fit if

• You want general cardiovascular maintenance and you'll give it a couple of months
• You can read an oleuropein figure off a label, or you'll ask us to
• You're not on medicines that lower blood pressure or blood sugar
• You'd rather have a conflicted evidence base explained than simplified

Check with us first if

• You take any blood pressure medicine. ACE inhibitors, ARBs, calcium channel blockers, diuretics or beta blockers. The effect may be additive.
• You take insulin or oral diabetes medicine, for the same reason.
• You take diltiazem or propranolol, where blood levels of the medicine may rise.
• You're pregnant or breastfeeding. The advice we hold is to avoid it, because safety information is lacking.
• It's for a child, where nothing's established.
• You react to olive tree pollen, which is the only allergy signal recorded for this plant.

• Standardised extract, 500 mg twice daily. Best known for: The classic clinical format. Absorption: Implied by clinical effect; no direct pharmacokinetics in our sources. Typical use: A flat 1,000 mg a day. Two trials and one meta-analysis subgroup used it.
• Standardised extract, 500 mg once daily. Best known for: Half the above. Absorption: As above. Typical use: The dose that worked in the diabetes trial and in one meta-analysis. Note the two meta-analyses disagree about which dose works.
• Extract labelled by oleuropein content. Best known for: The only honest way to compare two products. Absorption: Phenolic metabolites were recovered in urine 8 to 24 hours after a single dose. Typical use: Around 136 mg oleuropein with 6 mg hydroxytyrosol a day in the one trial that moved both blood pressure and lipids.
• Lower-phenolic extract. Best known for: Roughly 51 mg oleuropein a day. Absorption: As above. Typical use: One unreplicated crossover on insulin sensitivity. A separate review found low-dose extract lost to placebo on fasting glucose.
• Dried-leaf-equivalent labelling. Best known for: The Australian retail convention. Absorption: Not comparable to extract milligrams. Typical use: Only useful if the oleuropein figure is declared alongside it.
• Olive leaf tea or infusion. Best known for: The traditional preparation. Absorption: Phenolic load varies enormously with leaf, water and steeping. Typical use: An infusion can reach clinical phenolic loads, but one review's figure needed up to 990 mL a day to do it.
• Olive fruit and extra-virgin olive oil. Best known for: Same plant, different part. Absorption: Hydroxytyrosol-dominant rather than oleuropein-dominant. Typical use: A food with its own separate literature. Don't transfer olive oil evidence onto an olive leaf product.
• Sorbitan olivate (item 4677). Best known for: An olive-derived emulsifier in topical products. Absorption: Not applicable. Typical use: Formulation only, capped at 10% and not for use in the eye. It isn't a benefit-bearing ingredient.

Reference values. There's no Nutrient Reference Value or RDI for olive leaf. It's a herb, not a nutrient.

Typical supplemental range. Standardised extract at 500 to 1,000 mg a day, or extracts delivering roughly 100 to 136 mg of oleuropein a day. Most trials ran 8 to 14 weeks, with one going to 24.

Upper level. Schedule 1 sets no cap on item 3571 and no maximum daily intake has been set by NHMRC, FSANZ or the TGA. The only human upper-dose signal we hold is a single case report of behavioural changes in a 67-year-old taking 5.5 g a day. High-dose animal studies showed liver enzyme elevation, though human trials at studied doses found no change in liver function.

Worth knowing. Compare products on oleuropein per daily dose, not on extract milligrams and not on dried-leaf-equivalent grams. Those two aren't comparable to each other or to the trials. Because Schedule 1 sets no warning at all here, anything we tell you is a duty-of-care call rather than a regulatory one, which is a reason to be more careful rather than less. Your needs depend on your age, diet and health circumstances. Talk to one of our naturopaths in store.

Food first, where the diet allows it.

• Dried olive leaf: oleuropein has been reported at levels reaching 240 mg per gram of dried leaf, though real leaf varies widely by cultivar, season and drying
• Olive leaf infusion: up to 990 mL a day in reviewed trials, delivering 320.8 mg oleuropein and 11.9 mg hydroxytyrosol
• Olives and olive oil: the same phenolic family but hydroxytyrosol-dominant, with a separate clinical literature that doesn't transfer

This list is the part of the page we will not shorten. If any of it applies to you, talk to one of our naturopaths or your doctor before starting.

• Blood pressure medicines. Olive leaf may add to the blood-pressure-lowering effect. This is listed as a contraindication and it's the interaction that matters most here.
• Insulin and oral diabetes medicines. Possible additive lowering of blood sugar. Careful monitoring is warranted.
• Diltiazem and propranolol. Blood levels of these medicines may rise when combined with olive leaf.
• Pregnancy and breastfeeding. The guidance we hold is to avoid it, because information on safety and efficacy is lacking.
• Children. No paediatric evidence located. One trial in high-school athletes reported no safety issue, but it wasn't powered for safety and enrolled only 32 people.
• High doses. One case report describes behavioural changes in a 67-year-old taking 5.5 g a day, and high-dose animal studies showed liver enzyme elevation. Against that, human trials at studied doses found no change in liver function, total protein, albumin, urea or creatinine.
• Olive pollen allergy. Olive tree pollen can trigger severe respiratory allergies in susceptible people. That's a pollen reaction rather than a leaf-extract one, but it's the only allergy signal recorded.
• Everyone. Schedule 1 sets no warning statement and no dose cap for this ingredient, so every caution here is our judgement rather than a rule. Treat that as a reason for more care, not less.