Olive Leaf

Olive leaf is well tolerated and has more heart research than most herbs on the shelf. These are the questions our naturopaths ask in store, and most of them are about medicines you might already take.

A good fit if

• You want everyday heart and circulation maintenance, and you'll give it a couple of months
• You can read an oleuropein figure on a label, or you're happy to ask us
• You don't take medicines that lower blood pressure or blood sugar
• You'd like the mixed evidence explained honestly rather than simplified

Check with us first if

• You take any blood pressure medicine, such as ACE inhibitors, ARBs, calcium channel blockers, diuretics or beta blockers. The effects may add up.
• You take insulin or diabetes tablets, for the same reason.
• You take diltiazem or propranolol, because blood levels of these medicines may rise.
• You're pregnant or breastfeeding. The advice is to avoid it, because there isn't enough safety information.
• It's for a child, because there's no established safety information for children.
• You react to olive tree pollen, which is the only allergy 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 recommended intake for olive leaf. It's a herb, not a nutrient.

Typical supplemental range. Trials used 500 to 1,000 mg a day of standardised extract, or extracts giving roughly 100 to 136 mg of oleuropein a day. Most trials ran for 8 to 14 weeks, and one went to 24.

Upper level. Australia's permitted ingredients list (Schedule 1, item 3571) sets no limit, and the NHMRC, FSANZ and the TGA haven't set a maximum daily intake. The only human report of a problem at a high dose is a single case of behaviour changes in a 67-year-old taking 5.5 g a day. High-dose animal studies showed raised liver enzymes, though human trials at the doses studied found no change in liver function.

Worth knowing. Compare products on oleuropein per daily dose, not on extract milligrams or dried-leaf equivalent grams. Those two figures can't be compared with each other or with the trials. Australian rules set no warnings for olive leaf, so the advice we give you comes from our duty of care, and that's a reason for us to be more careful, not less. What you need depends on your age, diet and health, so talk to one of our naturopaths.

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.