Olive Tea: What Olive Leaf Tea Is, and What the Trials Measured
Olive tea is almost always olive leaf tea — an infusion made from the dried leaves of Olea europaea, the same tree that gives us olive oil. It is an old Mediterranean habit that has become a small online industry, and it is also one of the most confidently oversold drinks on the internet. Nearly every page selling or describing it leads with health outcomes. Very few mention that no such claim is permitted on a food label in Great Britain or the EU, that the pooled human evidence runs to three trials and 248 people, or that those trials mostly used a standardised capsule rather than a cup of tea. This guide covers what olive tea actually is, what the research measured, what the law allows anyone to say, and how to brew it so it does not taste like a hedge.
We do not sell olive leaf tea. For our own oil — from the same species, pressed rather than steeped — see our cold-pressed organic Marrakech olive oil.
The Short Answer
- “Olive tea” almost always means olive leaf tea: dried leaves of Olea europaea steeped in hot water. It is not made from the fruit, and it is not olive oil in a cup.
- The compound the marketing is built on is oleuropein — the bitter secoiridoid that also makes a green olive inedible straight off the branch.
- There is no authorised health claim for olive leaf or for oleuropein. The only olive entry on the permitted list in Regulation (EU) No 432/2012 is for olive oil polyphenols, and it attaches to olive oil at a measured threshold.
- The human evidence is thin. A 2025 systematic review in Phytotherapy Research screened 211 studies, found three that were eligible, and pooled 248 participants in total.
- Almost all of those trials used a standardised extract in a capsule — typically 1,000 mg a day — rather than an infusion. The one review that includes an infusion records a dose of around 990 mL a day.
- Processing matters more than most sellers admit: drying olive leaves above 50 °C lowers their phenolic content, and the drying method that raised the measured phenolic number produced the cup tasters liked least.
- Olive tea is a food, not a medicine. If you take prescribed medication, ask your GP or pharmacist before making it a daily habit.
What Olive Tea Actually Is
Olive tea is an infusion made by steeping the dried leaves of the olive tree, Olea europaea, in hot water. It is caffeine-free, faintly bitter and grassy, and it is made from neither the fruit nor the oil. Most packets sold as “olive tea” are simply olive leaf tea under a shorter name.
The leaf is a by-product. Olive groves are pruned every year, and the prunings have historically gone to animal feed, to mulch, or to a bonfire. Turning them into an infusion is a sensible use of something that already exists — which is the honest case for the drink, and a better one than most of what is written about it. The species is the same one behind every bottle of olive oil on every shelf; our guide to what the olive tree actually is covers the botany, including the seven subspecies Kew accepts and why the wild olive is not a separate taxon.
What the leaf carries in quantity is oleuropein, a secoiridoid compound. Oleuropein is why a green olive straight off the branch is inedible, and why an olive leaf infusion keeps a bitter edge that no amount of honey quite hides. It is chemically related to hydroxytyrosol, the compound the olive oil rules are written around — a relationship that gets stretched, in marketing, well past what it can bear.
One thing is worth stating plainly. The olive and its oil are honoured in the Prophetic Sunnah, and we write about that in our piece on olive oil in the Quran and the Sunnah. That tradition concerns the fruit and the oil. We are not going to stretch it to cover a leaf infusion, and you should be wary of anyone who does.
What the Human Evidence Actually Consists Of
Here is the whole of it, as plainly as we can put it. Two recent reviews have gathered the human trials on olive leaf and on its main compounds, and between them they describe a small, mixed and largely unfinished literature. Most of the enthusiasm you will read about olive leaf comes instead from laboratory and animal work, which is where this compound has been studied most; we are staying with the human trials, because that is the only place a statement about people could honestly come from.
Lachovicz and colleagues, writing in Phytotherapy Research in 2025, searched eight databases, screened 211 studies and found three that met their eligibility criteria, covering 248 participants in total. Their headline pooled figure — a pre-versus-post comparison across those three trials — was a systolic difference of −6.03 mmHg (95% CI −11.60 to −0.46) with an I² of 82%, alongside a diastolic difference of −2.38 mmHg (95% CI −4.96 to 0.20, p = 0.07) with an I² of 50%. An I² of 82% means the trials disagreed with one another substantially, and the diastolic interval crosses zero. A narrower sub-analysis restricted to the studies using 1,000 mg a day reported −11.45 mmHg and −4.65 mmHg with an I² of 0% — tidier, but resting on fewer studies still. The authors list variable trial quality and the exclusion of non-English studies among their limitations, and close by saying that further comprehensive clinical studies are essential. No GRADE certainty rating is attached to any of these pooled figures.
Frumuzachi and colleagues, in Antioxidants in 2024, took a wider view: 12 randomised controlled trials and 683 participants, covering oleuropein and hydroxytyrosol given as supplements, as pure compounds, or in enriched foods. The detail that matters most to anyone holding a teapot is the dose range they record. It runs from 5 mg a day of hydroxytyrosol at one end to 990 mL a day of olive leaf infusion — supplying 320.8 mg of oleuropein and 11.9 mg of hydroxytyrosol — at the other. The review describes its own results as contrasting and mixed, and calls for further work to establish optimal dose and duration.
Read that dose again, because it is the single most useful number on this page. The one included study that used an actual infusion used close to a litre of it a day, prepared from leaves whose composition had been measured. A mug made from an unlabelled bag of leaves, dried at an unknown temperature and stored for an unknown length of time, is not that.
| Review | What it gathered | Participants | Form and dose | Heterogeneity | The authors’ own caveat |
|---|---|---|---|---|---|
| Lachovicz et al., Phytotherapy Research, 2025 | 3 eligible trials, from 211 screened across eight databases | 248 | Olive leaf extract; the tidy sub-analysis was restricted to 1,000 mg a day | I² = 82% (systolic), I² = 50% (diastolic); no GRADE rating given | Variable trial quality; non-English studies excluded; further comprehensive clinical studies described as essential |
| Frumuzachi et al., Antioxidants, 2024 | 12 randomised controlled trials | 683 | Oleuropein and hydroxytyrosol as supplements, pure compounds or enriched foods; 5 mg/day hydroxytyrosol up to 990 mL/day of infusion (320.8 mg oleuropein, 11.9 mg hydroxytyrosol) | Not pooled into a single figure | Results described as contrasting and mixed; optimal dose and duration unresolved |
None of this makes olive leaf tea a bad drink. It makes it a drink whose human evidence base is three trials, 248 people, wide disagreement between studies, and doses that mostly arrived in capsules. That is a reasonable thing to say out loud, and almost nobody selling it does.
What the Law Actually Permits
Health claims on food are not a matter of opinion in Great Britain or the EU. Under Regulation (EC) No 1924/2006, a health claim may only be made on a food if it appears on an authorised list, and the list of permitted general-function claims sits in the Annex to Regulation (EU) No 432/2012.
We read that Annex for this article. It runs to 249 rows. There is no entry for olive leaf, no entry for olive leaf extract, and no entry for oleuropein as a substance in its own right. There is exactly one olive entry, and this is what it says.
| Subject | On the permitted list? | The authorised wording | Conditions of use |
|---|---|---|---|
| Olive oil polyphenols | Yes | “Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress” | May be used only for olive oil containing at least 5 mg of hydroxytyrosol and its derivatives (e.g. oleuropein complex and tyrosol) per 20 g of olive oil, and the consumer must be told the effect is obtained with a daily intake of 20 g of olive oil |
| Olive leaf, or olive leaf extract | No entry | — | — |
| Oleuropein as a substance | No entry of its own | Appears only as an example of a hydroxytyrosol derivative counted inside the olive oil entry above | — |
Two things are worth noticing about that authorised wording. The first is its shape: a named substance, a measurable threshold, a specific food, and a requirement to tell the reader what daily intake the effect is tied to. That is what a claim looks like when somebody has had to prove it. The second is where oleuropein appears — not as a subject, but as an example of a hydroxytyrosol derivative that counts towards the 5 mg in 20 g of oil. It is a measurement rule for oil. It says nothing about leaves, and it cannot be borrowed.
We should be explicit here, since we sell olive oil ourselves: we have not had our own oil analysed against that threshold, so we do not make that claim either. For the equivalent argument about what a legal grade on a bottle does and does not guarantee, see our guide to what extra virgin olive oil actually means.
In Great Britain the equivalent permitted list continues to apply as assimilated law — the term that replaced “retained EU law” under the Retained EU Law (Revocation and Reform) Act 2023.
And now the honest counterweight, because this is where writing about food-claim regulation usually goes wrong in one direction or the other. An unauthorised claim is a claim that has not been substantiated to that standard. It is not a finding that the claim is false. The absence of a permitted claim tells you nobody has proved the case; it does not tell you there is no case. What it does tell you is that anyone printing an outcome on a packet is making a promise the law has not let them make.
How to Make Olive Leaf Tea, and Why Processing Changes the Cup
Two recent food-science papers make this section worth writing, because between them they show that most of what determines your cup happened before you bought the leaves.
Ramírez and colleagues, in Foods in 2023, modelled the dehydration of olive leaves specifically for infusion use. They found that drying temperatures above 50 °C reduced the phenolic concentration of the leaves; that storing the leaves for 24 hours at room temperature before drying considerably reduced that loss; and that the finer the grind, the more of both the bioactive and the coloured compounds diffused into the water.
Tripodi and colleagues, in Foods in 2026, compared air drying at 50 °C for three hours against microwave drying at 400 W for four minutes, then had the resulting infusions assessed by a descriptive sensory panel and by ordinary consumers. Microwave drying significantly raised total phenolic content — though not proportionally the measured antioxidant capacity — and shifted the aroma away from the green and floral notes of the air-dried leaves towards fruitier aldehydes and ketones. The microwave-dried teas were more bitter and more astringent, and consumers showed a clear preference for the air-dried version.
That is a small result with a large lesson. The processing choice that maximised the number on the certificate produced the cup people liked least. It is worth remembering the next time a bigger number is offered as proof of a better product — including in olive oil, where the same trap is set every day. Our guide to choosing a quality olive oil works through what the numbers on a bottle can and cannot tell you.
| Processing choice | What the research found | What it means for your cup |
|---|---|---|
| Drying above 50 °C | Reduced the phenolic concentration of the leaves (Ramírez et al., Foods, 2023) | Hard, hot drying costs you the compound the whole category is sold on |
| 24 hours at room temperature before drying | Considerably reduced the loss of phenols (Ramírez et al., 2023) | A handling step you cannot see, and one nobody prints on a packet |
| Finer grinding | Greater diffusion of both bioactive and coloured compounds into the infusion (Ramírez et al., 2023) | Cut or crushed leaves give up more than whole ones |
| Microwave drying (400 W, 4 min) against air drying (50 °C, 3 h) | Microwave drying raised total phenolic content but not proportionally the antioxidant capacity, and produced a more bitter, more astringent tea (Tripodi et al., Foods, 2026) | The higher number came with the less pleasant cup |
| Consumer preference | A clear preference for air-dried leaves (Tripodi et al., 2026) | If a packet says how the leaves were dried, air-dried is the safer buy |
The practical part is short.
- Use roughly a teaspoon of dried leaves per large mug, or a tablespoon per litre.
- Water just off the boil, rather than violently boiling.
- Steep five to ten minutes. Longer draws out more bitterness, not more virtue.
- Cut or lightly crush the leaves rather than brewing them whole — finer material gives up more of its content to the water.
- Buy leaves that say how they were dried; air-dried is the version drinkers preferred.
- Store them airtight, dark and cool, as you would any dried leaf.
- It is caffeine-free, so the time of day is not a constraint.
- If it tastes like a hedge, you steeped it too long or the leaves were dried too hard.
Safety, and When to Ask Someone Qualified First
Olive leaf tea is a food. It is not a medicine, and it is not a substitute for medical care.
The trials described above measured cardiometabolic parameters, which is a reason to check rather than a reason to worry. If you take prescribed medication of any kind, or you are pregnant or breastfeeding, ask your GP or pharmacist before making a daily habit of any concentrated herbal infusion. Not because an interaction has been established — it has not been properly studied — but because asking costs nothing and guessing is the wrong order of operations.
There is a second, quieter problem. Most packets tell you almost nothing. Nothing on a typical bag states the drying temperature, the harvest year, the storage history or the oleuropein content, which means you cannot know even approximately what is in your cup. That is not a scandal, and it is not unusual for an agricultural by-product sold loose. But it does mean that the confident dosage advice you will find online is being offered about a material nobody has characterised.
The Objections Worth Taking Seriously
The first objection is aimed straight at us: you sell olive oil, so of course you are sceptical about olive leaf tea. Fair enough. But the standard applied here is the one we apply to ourselves, and it costs us more than it costs the tea. We publish no polyphenol figure, no acidity result and no peroxide value for our own oil, because we have not had the panel done. We would rather say so than print a number we have not measured. If that standard reads as hard on a packet of leaves, it is because it is hard on us first.
The second objection is a better one. Absence of an authorised claim is not absence of an effect — plenty of things work before anyone gets round to substantiating them. That is true, and we said so above. The reason we still would not build a daily habit on the current evidence is not the regulator; it is three trials, 248 people, an I² of 82%, and the fact that the doses producing the tidiest numbers arrived in capsules.
The third is practical. If a study got 320 mg of oleuropein into people using an infusion, surely I can do that at home? Roughly a litre a day, from leaves whose composition had been measured in advance. You can drink a litre of olive leaf tea a day if you want to. What you cannot do, from an ordinary packet, is know what is in it.
Why Sidr & Stone
This article is mostly about a drink we do not sell, which is the right proportion for it. The reason we wrote it is that the pattern in olive leaf tea marketing — an outcome on the front of the packet and nothing checkable on the back — is the same pattern that runs the length of the olive oil aisle, and it is the pattern our own product is built against.
- Single-estate — one family-owned grove on the plains outside Marrakech, Morocco, with no blending across origins.
- Rain-fed — the trees are not irrigated; they take what the season gives them.
- Organically grown — no synthetic fertilisers, pesticides or herbicides.
- Single harvest — a small batch pressed once a season; when it is gone, it is gone until the next one.
- Cold-pressed within hours of harvest — which is what preserves flavour, aroma and polyphenols.
- Unfiltered extra virgin — minimally processed, and it may show natural sediment, which is normal for an unfiltered oil.
- 100% natural — one ingredient, olive oil, with nothing added.
- Dark glass with a gold label — packaging that protects the oil from light.
- Halal certified.
- 10% of profits to charity — a commitment that applies across every Sidr & Stone product.
- Fulfilment in the UK, EU, and US.
We will not tell you Sidr & Stone is the best olive oil — that is exactly the sort of unfalsifiable claim this article has spent its length picking apart. What we will say is that the oil is single-estate Moroccan, rain-fed, organically grown and cold-pressed within hours of harvest, and that the evidence of that care is in the taste, the colour and the size of the season’s small batch. For what a named single estate does and does not guarantee, see our note on single-estate olive oil.
Frequently Asked Questions
What is olive tea?
Olive tea is an infusion made from the dried leaves of the olive tree, Olea europaea. It is not made from olives, and it is not olive oil. Almost everything sold as olive tea is olive leaf tea under a shorter name.
Is olive tea the same as olive leaf tea?
In practice, yes. “Olive tea” is the shorter search term; olive leaf is what is in the bag. If you find a product that genuinely is not leaf-based — a blend of ordinary tea with olive leaf, for instance — the ingredients list will say so.
Does olive leaf tea contain caffeine?
No. Olive leaf does not come from the tea plant, Camellia sinensis, so an olive leaf infusion is naturally caffeine-free. Blends that combine olive leaf with actual tea will carry caffeine from the tea component.
What does olive leaf tea taste like, and how do I make it less bitter?
Grassy, faintly hay-like, with a bitter edge that comes from oleuropein. Steep for five to ten minutes rather than longer, use water just off the boil, and choose air-dried leaves: in a 2026 sensory study in Foods, microwave-dried leaves produced a more bitter and astringent tea that consumers liked less.
Are the health claims on olive leaf tea packets allowed?
No. A health claim may only be made on a food if it appears on the authorised list, and there is no entry for olive leaf or for oleuropein. The single olive entry in the Annex to Regulation (EU) No 432/2012 is for olive oil polyphenols, and its conditions attach to olive oil at a measured threshold.
How much oleuropein is in a cup of olive leaf tea?
Nobody can tell you from a packet, because packets do not state it. For scale: the one review to include an olive leaf infusion among its trials records a dose of around 990 mL a day supplying 320.8 mg of oleuropein, prepared from leaves whose composition had been measured.
Can I drink olive leaf tea every day?
It is a herbal infusion, and many people do. If you take prescribed medication of any kind, or you are pregnant or breastfeeding, ask your GP or pharmacist first — the interactions have not been properly studied, and that is the reason to ask rather than a reason to assume.
Is olive oil a medicine?
No. Olive oil is a food, not a medicine. It has a long traditional history — including being honoured in the Prophetic Sunnah — and a substantial body of modern research, particularly around polyphenols, cardiovascular health, and the Mediterranean diet pattern. It can be a worthwhile part of a healthy routine, but it does not cure diseases and is not a substitute for medical care. Be cautious of any olive oil marketed with specific disease-cure claims.
Final Thoughts
Olive tea is a decent drink carrying an indecent amount of nonsense. The leaf is real, oleuropein is real, and turning grove prunings into something people enjoy drinking is a genuinely good idea. What is not real is the confidence. Three trials and 248 people is not a settled question, an I² of 82% is not agreement, and a capsule is not a cup.
The habit worth taking from this is not really about tea. When a product is sold on an outcome, look underneath it for the thing that could in principle be checked — a named substance, a threshold, a measurement, a date. The authorised olive claim has all four, which is exactly why it is the only one on the list. Most of what you will read about olive leaf has none of them.
We hold ourselves to that test and currently fail part of it: we have not yet had our own oil analysed, so we publish no polyphenol figure and make no claim that rests on one. What we can tell you is where the oil comes from and how it was made, because we know. Our cold-pressed organic Marrakech olive oil — single-estate, rain-fed, organically grown and pressed within hours of harvest — is open for pre-order on its limited first harvest. Estimated shipping from November 2026. Fulfilment in the UK, EU, and US.
Pre-Order Sidr & Stone Organic Marrakech Olive Oil — Limited First Harvest →
Disclaimer: This article describes published research and food-law provisions at the time of writing; research findings and regulations change, and readers should check current sources. It reports what studies measured and does not recommend olive leaf tea for any purpose. Olive oil is a food, not a medicine, and is not a substitute for medical treatment of any condition. For any health concern, consult a qualified medical professional.