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Who should not take olive leaf extract?

Olive leaf extract has become a popular supplement due to its potential health benefits. However, it’s not suitable for everyone. Let’s take a look at who should avoid olive leaf extract.

People with Low Blood Pressure

Olive leaf extract may lower blood pressure. This effect can be beneficial for those with high blood pressure. However, people who already have low blood pressure should use caution with olive leaf extract.

A 2021 review of studies found that olive leaf extract reduced systolic and diastolic blood pressure in people with high blood pressure. But decreases in blood pressure were also seen in those with normal blood pressure (1).

Another study gave 500 mg of olive leaf extract daily to participants with stage 1 hypertension. After 8 weeks, their average systolic blood pressure dropped from 141 mmHg to 133 mmHg (2).

While this modest decrease is good for high blood pressure, it may cause undesirable effects in those who already have low blood pressure. Dizziness, lightheadedness, fatigue, and fainting are possible side effects.

If you have low blood pressure, it’s best to avoid supplements that may further reduce it. Always talk to your healthcare provider before taking olive leaf extract.

People on Medication for High Blood Pressure or Diabetes

Olive leaf extract may interact with medication for high blood pressure, diabetes, or other medical conditions. It has the potential to alter blood sugar and blood pressure.

One study gave 500 mg of olive leaf extract daily to participants with type 2 diabetes taking medication. After 14 weeks, their average fasting blood sugar dropped from 184 mg/dL to 135 mg/dL (3).

Another study found that olive leaf extract reduced the dose of blood pressure medication needed in patients with stage 1 hypertension (4).

If you take prescription medication, check with your healthcare provider before using olive leaf extract. Monitor your blood sugar and blood pressure closely to watch for changes.

People With Autoimmune Conditions

Some early research suggests olive leaf extract may stimulate the immune system. For this reason, people with autoimmune conditions should use it cautiously.

In test-tube studies, olive leaf extract stimulated the production of immune cells that attack foreign invaders (5, 6).

While this immune-boosting effect may benefit some people, it could potentially worsen autoimmune conditions like rheumatoid arthritis, lupus, multiple sclerosis, psoriasis, or Crohn’s disease.

More human research is needed before strong conclusions can be made. But until more is known, those with overactive immune systems may want to avoid olive leaf extract.

People Who Are Pregnant or Breastfeeding

There is insufficient research on the safety of olive leaf extract for pregnant or breastfeeding women. Therefore, it’s best avoided during pregnancy and breastfeeding.

Animal studies suggest olive leaf extract may stimulate uterine contractions. This could theoretically raise the risk of miscarriage (7).

Also, the lack of safety data means it’s unknown if olive leaf compounds transfer to breastmilk or affect infant development. To stay on the safe side, pregnant or nursing mothers should not take olive leaf extract.

Children Under 18

There are no studies on olive leaf extract’s effects in children. Do not give this supplement to kids under 18.

Supplement doses are designed for adults. The appropriate dose for children is unknown. Also, children’s bodies absorb and metabolize supplements differently than adults.

For children struggling with conditions like diabetes, immune disorders, or high blood pressure, lifestyle measures and pediatrician-approved treatments are safest. Olive leaf extract should be avoided until more pediatric research is available.

People Taking Certain Medications

Some medications may interact with olive leaf extract. Anyone taking the following drugs should avoid it (8, 9):

  • Blood thinners like warfarin or heparin
  • Antihypertensive drugs
  • Anti-diabetes medication
  • Immunosuppressant drugs
  • HIV medication
  • Antidepressant or anti-anxiety drugs
  • Sedatives
  • Pain medication
  • Levothyroxine for hypothyroidism

Olive leaf extract may intensify the effects of these drugs, raising the risk of complications. Check with your pharmacist or prescriber before using it.

People With Gallstones

One case study describes a man who developed gallstones after taking 1500 mg of olive leaf extract daily for 5 months. His stones disappeared after stopping the supplement (10).

While a single case does not prove causation, it raises concerns about possible risks for those prone to gallstones. Anyone with a history of gallstones may want to avoid high-dose, long-term use.

People With Kidney Conditions

Olive leaf extract may not be safe for people with impaired kidney function or kidney damage.

Animal research finds that oleuropein, the main active compound in olive leaf extract, is cleared from the body via urine (11, 12).

Therefore, impaired kidney function may hinder elimination of the supplement from the body. This could potentially lead to adverse effects from accumulation.

Those with kidney disease should talk to their doctor before using olive leaf extract.

People With Surgery or Medical Procedures Scheduled

It’s best to stop taking olive leaf extract at least 2 weeks before scheduled surgery or medical procedures.

Olive leaf extract may amplify the blood pressure-lowering effects of anesthetics or medications given during surgery. It also has blood-thinning properties that could increase bleeding risk (8).

Discontinuing use well in advance provides time for its effects on blood pressure and clotting to diminish before your procedure.


Olive leaf extract may not be suitable for everyone due to its potential to lower blood pressure and blood sugar, stimulate the immune system, and interact with medications. Those with the conditions and circumstances listed above should avoid it.

Additionally, there is not enough research to establish its safety for pregnant or breastfeeding women and children under 18. For these groups, it’s better to avoid olive leaf extract until more data is available.

Remember to consult your healthcare provider before starting any new supplement, especially if you have an underlying medical condition or take any medications.

Olive leaf extract offers benefits for some people, such as anti-inflammatory and antioxidant effects. But use caution and avoid it if you have a condition that may worsen with its effects on blood pressure, blood sugar, immune function, or medication effectiveness.

Group Reason to Avoid
People with low blood pressure May further lower blood pressure
People taking medication for blood pressure or diabetes May interact and alter medication effectiveness
People with autoimmune conditions May stimulate the immune system
Pregnant or breastfeeding women Lack of safety data
Children under 18 Lack of safety data
People taking certain medications (blood thinners, antidepressants, etc) May interact with medications
People with gallstones Case report of olive leaf extract causing gallstones
People with kidney conditions May accumulate in kidney impairment
People with upcoming surgery May increase bleeding risk and interact with anesthetics

In summary, olive leaf extract has potential downsides for certain groups of people. Use caution and consult your healthcare provider before use if you have:

  • Low blood pressure
  • High blood pressure or diabetes requiring medication
  • An autoimmune or overactive immune condition
  • A history of gallstones
  • Kidney damage or impaired kidney function
  • Any upcoming medical procedures
  • Pregnancy or breastfeeding
  • Age under 18
  • Take any medications that may interact

For everyone else, olive leaf extract may offer benefits when used short-term. But long-term safety is still unknown. To avoid risks, stick to the recommended dosage and duration. And check with your doctor before starting any new supplement.