Evigrade

Olive leaf extract (Olea europaea, oleuropein)

Plant antioxidant, supplement. In EU – traditional herbal medicinal product (EMA HMPC monograph 2014)

ATC code: A11JA-OLIVE-LEAF

Brand names – supplements: Now Olive Leaf, Solgar Olive Leaf, Gaia Herbs Olive Leaf, Barlean's Olive Leaf ComplexSupplements are not tested in clinical trials and are not registered as medications.

Updated · Methodology

Marketing claims without evidence base

The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.

D

Cancer prevention through supplements

Not recommended

Olive leaf extract (Olea europaea) with oleuropein is sold as a supplement for cancer prevention. There is no convincing evidence of benefit for this use – the data needed to show that such supplements lower cancer risk simply are not there. What does lower risk are approaches with proven benefit: quitting smoking, age- and risk-appropriate screening, and vaccination against HPV and hepatitis B. Do not use this extract in place of prevention or treatment with proven benefit, since that can mean missing the care you need.

D

Herpes simplex

Not recommended

Olive leaf extract (Olea europaea) and its compound oleuropein are marketed as an immune supplement and antiviral support, including for herpes simplex. No convincing benefit has been shown for herpes – there is no evidence base for this use. Herpes simplex flare-ups respond to antiviral drugs such as aciclovir, valaciclovir, and famciclovir, and the sooner treatment starts, the better it works. Olive leaf extract is harmless, but don't use it instead of treatment with proven benefit, since that can mean missing the care you actually need.

ICD-10: B00 · ICD-11: 1F00.Z

D

Hypertension

Not recommended

Olive leaf extract is sold as a «natural antihypertensive» promising blood pressure reduction in stage 1. The Susalit 2011 RCT in 232 prehypertensive and stage-1 hypertensive patients compared olive extract 1000 mg/day with captopril 12.5–25 mg twice daily over 8 weeks: both lowered systolic BP by about 11 mmHg; the difference was not significant. Limitations: single-centre design, no placebo group, small sample, short duration. No RCT on olive leaf extract with cardiovascular mortality, MI or stroke endpoints. HMPC 2014 recognises «traditional use for mild blood pressure elevation». 2024 and SEH-LELHA 2022 in HTN first-line list lifestyle modification (DASH, salt restriction, physical activity) and as needed ACE inhibitors or ARBs combined with diuretic or calcium channel blocker; olive leaf is not in international guidelines. If olive leaf extract was recommended as a substitute for ACE inhibitor or sartan in confirmed HTN, consider seeking a second opinion.

ICD-10: I10 · ICD-11: BA00

D

Immune support and respiratory infection care

Not recommended

Olive leaf extract (Olea europaea), whose active component is oleuropein, is marketed as a supplement for immune support and for preventing colds and other respiratory infections. There is no convincing evidence for this use: good-quality clinical trials showing an effect on how often people catch a respiratory infection or how it runs have not been done. For a cold, rest, fluids, and symptom relief are what actually help, and the main protection against flu is vaccination. The substance itself is harmless in normal dietary amounts, but do not use it instead of treatment with proven benefit, since that can mean missing the care you need.

How to read tiers A–F
  • AStrong evidence – first or second line in international guidelines
  • BRecommended in selected cases
  • CStudy data contradict each other
  • DBenefit not proven, no documented harm
  • FDocumented harm, or risk without benefit

Mechanism of action

Olive leaves contain secoiridoids (oleuropein, ligstroside, oleocanthal), flavonoids (rutin, luteolin, apigenin) and triterpenes (oleanolic, maslinic acid). Oleuropein is hydrolysed in the intestine to hydroxytyrosol – one of the most potent natural antioxidants. In vitro oleuropein and hydroxytyrosol suppress oxidation, inhibit NF-κB activation, reduce pro-inflammatory cytokine synthesis. Animal models show moderate antihypertensive effect (via ACE inhibition and NO synthase activation), blood glucose reduction and antimicrobial effect. The human mechanism with 500–1000 mg/day extract intake is weakly clinically characterised. Oral oleuropein bioavailability is moderate (≈50–60%). HMPC 2014 recognised olive leaves as a traditional herbal medicinal product for «mild blood pressure elevation and malaise» based on 30 years of traditional Mediterranean medicine use.

Safety

Contraindications

  • Pregnancy and lactation
  • Children under 18 (EMA HMPC – insufficient data)
  • Hypotension (theoretical risk of further BP reduction)
  • Antihypertensive therapy (ACE inhibitors, ARBs, diuretics, beta-blockers, CCBs) – additive effect risk
  • Hypoglycaemia and insulin or sulphonylurea therapy (theoretical additive effect risk)
  • Allergy to Oleaceae family plants

Serious adverse effects

  • Orthostatic hypotension combined with antihypertensives
  • Hypoglycaemia combined with insulin or sulphonylurea
  • Allergic reactions (rare)
  • Masking of HTN symptoms with delayed proven antihypertensive prescription in a high cardiovascular risk patient

Common adverse effects

  • Nausea
  • Epigastric pain
  • Diarrhoea
  • Headache
  • Dizziness (with lowered BP)

Pregnancy: can you take Olive leaf extract (Olea europaea, oleuropein)?

No RCT data in pregnancy with the extract. Olive oil as part of the diet is safe. Concentrated olive leaf extract supplements (500–1000 mg/day) in pregnancy have not been studied – avoid. EMA HMPC 2014 lists pregnancy as contraindication.

Breastfeeding: can you take Olive leaf extract (Olea europaea, oleuropein)?

No data on oleuropein milk transfer. EMA HMPC 2014 lists lactation as contraindication. Lactating women should avoid.

Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.

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Frequently asked

What is Olive leaf extract (Olea europaea, oleuropein) used for?

Olive leaf extract (Olea europaea, oleuropein) is evaluated for the following indications with varying evidence strength: Cancer prevention through supplements (evidence tier D), Immune support and respiratory infection care (evidence tier D), Hypertension (evidence tier D). See the full indication matrix with dosing and citations above on this page.

What are the side effects of Olive leaf extract (Olea europaea, oleuropein)?

Common side effects of Olive leaf extract (Olea europaea, oleuropein) (≥ 1 in 100): Nausea, Epigastric pain, Diarrhoea, Headache, Dizziness (with lowered BP). See the Safety section for uncommon and serious reactions.

Is Olive leaf extract (Olea europaea, oleuropein) safe during pregnancy?

No RCT data in pregnancy with the extract. Olive oil as part of the diet is safe. Concentrated olive leaf extract supplements (500–1000 mg/day) in pregnancy have not been studied – avoid. EMA HMPC 2014 lists pregnancy as contraindication.

Is Olive leaf extract (Olea europaea, oleuropein) compatible with breastfeeding?

No data on oleuropein milk transfer. EMA HMPC 2014 lists lactation as contraindication. Lactating women should avoid.

Who should not take Olive leaf extract (Olea europaea, oleuropein)?

Olive leaf extract (Olea europaea, oleuropein) is contraindicated in: Pregnancy and lactation; Children under 18 (EMA HMPC – insufficient data); Hypotension (theoretical risk of further BP reduction); Antihypertensive therapy (ACE inhibitors, ARBs, diuretics, beta-blockers, CCBs) – additive effect risk; Hypoglycaemia and insulin or sulphonylurea therapy (theoretical additive effect risk). Full list in the Safety section.

Other drugs in this group

Omega-6 polyunsaturated fatty acids (linoleic acid and GLA), Omega-9 monounsaturated fatty acid (oleic acid), Panax ginseng (Korean/Chinese ginseng), Pantothenic acid, Rhodiola rosea (golden root), Stinging nettle root (Urtica dioica, radix), L-threonine + pyridoxine (Biotredin), Grape seed extract (Vitis vinifera, oligomeric proanthocyanidins)