Olive Leaf Side Effects - a temporary worsening of symptoms

When experienced, olive leaf side effects usually take the form of a temporary aggravation of existing symptoms, or symptoms of detoxification.

Jarisch-Herxheimer or Herxheimers reaction

This reaction, not exclusive to olive leaf extract, is named after the men who first described it, Adolf Jarisch and Karl Herxheimer, dermatologists working on the treatment of Syphilis in 1895.

It is an immune response to the release of toxins from pathogens which have been destroyed, in this case by the olive leaf extract.

Simply put, the reaction proceeds as follows:
  1. Olive leaf compounds attack and damage the cells of a large number of pathogens. (disease-causing microbes)
  2. The dead pathogens leak toxins, break down and are absorbed by surrounding tissues, which were already displaying symptoms caused by the infection of the pathogens in the first place.
  3. This increase in the concentration of toxins worsens the original symptoms and elicits a further immune response from the body causing histamine release, swelling and pain.
  4. The body ramps up its detoxification and cleansing processes which may result in other uncomfortable symptoms.
  5. As the overload of dead organisms is reduced and removed from the body, healing and a surge of energy and feeling of good health follows.
Drinking 4-6 glasses of purified water daily helps the body eliminate these toxins more quickly. The tissue surfaces where most discomfort may be felt are the mucous membranes of the mouth, oesophagus, stomach, intestines, sexual and urinary organs, ears, lungs and membranes surrounding the brain and synovial linings of the joints. These can give rise to the following olive leaf side effects:
  • Dull headaches

  • Muscle and joint pain

  • Feverishness and sweating

  • Nausea

  • Sore throat and nasal passages

  • Vaginal irritation especially in the case of yeast/fungal infections
These olive leaf side effects, when they do occur, normally last only for a few days and are generally mild.

If infections being treated are more severe, the side-effects may be worse and last longer and a reduction in dosage may be necessary to reduce discomfort.
Treatment can also be temporarily suspended to allow the body to deal with the overload more easily, and then resumed at a lower dosage to keep the die-off effect at a manageable level.

Herxheimers reaction is regarded as a positive sign, meaning that the treatment is working and is killing off the offending pathogens.

Other Olive Leaf Side Effects

  1. Olive leaf side effects may include dizziness in people who have low blood-pressure, by lowering it further. This is usually prevented by taking small doses until your body is used to it.
    Some people however may have to stop taking olive leaf extract for this reason and caution should be exercised initially by people with low blood pressure.

  2. Stomach irritation. This can affect some people using strong capsules or tinctures.
    Dilute the tinctures in water until the alcohol concentration is about 20% for best gastric absorption. Dilute further if still too strong.
    Capsules can be taken with food to minimize stomach aches, cramps and diarrhoea, but this will potentially reduce their virucidal activity. It is better to go for a weaker or more balanced capsule containing extract and powdered leaf.

  3. Severe Nausea/Vomiting. A small percentage of people experience this, especially when taking highly concentrated capsules as a first olive leaf extract product. It is best to start off with weaker capsules or a tincture or mild olive leaf tea and progress to the higher doses, especially when dealing with digestive tract problems such as yeast overgrowth or "leaky gut syndrome.".
    In this way you can more easily differentiate between a Herxheimer reaction which is good news, if uncomfortable, and an allergic response which will not go away after a few days but get worse.

  4. Diarrhoea. This may be caused by stomach irritation described above, or in a few cases where I have come across it, it involved people with candida overgrowth in the gut.
    When it turns parasitic, candida albicans forms filaments which embed themselves in the gut lining replacing and excluding the beneficial probiotic gut bacteria. When olive leaf extract damages these filaments, a Herxheimer reaction may occur as described above causing a loose stool.

  5. Acid reflux/Heartburn. This is experienced by a few people after taking olive leaf tinctures or capsules.
    It appears to happen mostly to acid reflux sufferers after taking peppermint-flavoured glycerine tinctures, although it has occasionally been reported by people taking other forms/flavours of olive leaf extract.
    As peppermint relaxes smooth muscle, it can relax the lower oesophageal or cardiac sphincter(valve) entering the stomach, already leaky in an acid reflux sufferer, causing reflux and heartburn.
    It can sometimes be overcome by taking an unflavoured tincture, or by diluting it in tea or water.
    Some people can still take mild olive leaf capsules.

Drug Interactions

Drug interactions with olive leaf extract are not well documented. The main concern is that olive leaf may magnify or counteract the effects of the drug being taken which could have serious implications.

Where the drugs taken have no overlap with olive leaf side or therapeutic effects, it may be safe to take them both but this is best discussed with your doctor.

Common sense should be the guide based on the known traditional, anecdotal and potential researched effects of olive leaf extract.

  1. Olive leaf extract lowers high blood pressure.
    Do not take olive leaf extract while on blood pressure medication without consulting your physician. If he/she is agreeable, start off with small doses. A reduction in or adjustment to the frequency of your other medication dosage may become necessary.
    This also applies if you wish to take olive leaf extract for a cold for example.

  2. Olive leaf extract demonstrates hypoglycaemic and antidiabetic properties in animals.
    If on diabetic medication, start with small olive leaf doses to gauge the effect or check with your physician beforehand.

  3. Olive leaf extract may increase the effect of blood thinners such as Warfarin as it tends to prevent blood platelets from sticking together. If on Warfarin or other blood thinners, check with your physician before taking olive leaf extract.

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Some final notes

If pregnant especially or breastfeeding, do not take olive leaf extract unless under the guidance of a qualified and informed health care practitioner.
While there are no known adverse effects, no research has been done to establish safety under these circumstances.

If you are using olive leaf for the first time, always start with low dosages to gauge the effect on your body.

Olive leaf sometimes attacks a dormant pathogen left in your body from long ago resulting in a brief return of old symptoms as it eliminates the offender.
This may seem disadvantageous at first but bear in mind that dormant pathogens can become active again as you age and your immune system begins to weaken or become overloaded.
It may be better to get rid of them while you have the upper hand.


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