Ingestion of essential oils get a bad reputation for causing liver damage. But what are the effects of essential oils on the liver? Studies have reported adverse reactions from depletion of metabolizing enzymes to death.  Conversely, studies have also show liver protection from essential oils.  Let’s look at how essential oils are metabolized to better understand the risks of essential oils on the liver.

What is the Risk when you Ingest Essential Oils?

When essential oils are metabolized (the same as when other external compounds are metabolized),  electrophiles are sometimes produced.  Electrophiles are highly reactive molecules that require additional processing to prevent them from becoming toxic. Any substance, in sufficient quantities, can overwhelm the liver and produce more electrophiles than the liver can metabolize and this puts the liver at risk. Therefore it is important to only ingest small amount of essential oils so the risk of electrophile production is lowered.

The Critical Role of Glutathione

Most foreign substances, including essential oils can potentially damage the liver is by depletion of glutathione.  Glutathione is one of the most potent detoxifying substances in the body. It is responsible for removing a wide variety of foreign chemicals from the body. Importantly, it takes a lot of essential oils to deplete glutathione, produce electrophiles, or cause liver damage. Studies suggest that 0.5 mL/kg of Cassia essential oils in rats can deplete glutathione.  If this data were scaled up,  it would take 35 mL to start to deplete glutathione.

A report of a one-time ingestion 30 mL of pennyroyal essential oil resulted in massive hepatic necrosis in an 18-year old girl, and therefore ingestion of excessive amounts of essential oil is not recommended.  The risk of ingesting large amounts of oil is also evident in two case reports of ingestion of between 5-20 mL of clove essential oil in two children aged 15 months and 2 years, both of whom suffered liver damage as a result. In rats, large doses of menthol in soybean oil (equivalent to 15 mL/day) for 28 days caused vacuoles in the liver. Therefore, it is likely that damage to the liver is dependent on the dose and that massive doses, especially massive doses over time, may cause damage.

Can Essential Oils Protect the Liver?

On the other hand, certain essential oils, and some essential oil constituents have protected against damage from foreign substances.  Fennel and thyme oil protected against carbon tetrachloride damage, and garlic oil against acetaminophen damage to the liver.  Essential oils constituents such as thymoquinone can also increase the amount of glutathione. This helps the body eliminate to toxins.

Bottom Line

As with everything essential oil  related, the dose is absolutely, critically important. I choose to ingest essential oils on a daily basis, but I do not choose to over use them or ingest a lot of at one time. If you want to avoid negative effects of essential oils on the liver, be sure to use small amounts.

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