Some essential oils, such as eucalyptus, thyme, tea tree, lavender, and peppermint, may help alleviate some flu symptoms and protect against the flu virus.
Essential oils (EOs) are oils that derive from certain parts of plants, such as the seeds, leaves, or roots. These oils contain chemical compounds, some of which may help to treat certain ailments, such as influenza (flu).
This article outlines 10 essential oils and presents research into their effectiveness against the flu virus or flu symptoms. We also offer advice on when to contact a doctor about flu.
Most of the research investigating the use of essential oils (EOs) for flu uses in vitro studies, meaning scientists test the EOs or their compounds against cell cultures in a test tube or petri dish.
This makes it difficult for scientists to determine the effectiveness of these substances in living animals, including humans.
It is also important to note that certain EOs can interact with other medications or supplements a person is taking. A person should always talk with a qualified healthcare professional and certified aromatherapist before ingesting EOs as this is generally not recommended.
Topical application of certain oils can irritate the skin. Even if an essential oil is safe to apply to the skin, a person must first dilute it in a carrier oil to reduce the risk of skin damage. Two popular carrier oils are coconut oil and jojoba oil.
A person can also inhale essential oils by placing one or two drops in water inside an oil diffuser. This will expel a mist around the room, dispersing the scent into the air.
A person can also put one or two drops of essential oil into a bowl of hot water and then inhale the fumes.
Below are 10 essential oils that may help to protect against the flu virus or treat some of the symptoms of flu.
While research suggests there are health benefits, the FDA doesn’t monitor or regulate the purity or quality of essential oils. It’s important to talk with a healthcare professional before using essential oils and research the quality of a brand’s products. Always do a patch test before trying a new essential oil.
Eucalyptus is a genus of flowering plants consisting of more than 900 species and subspecies. Most are native to Australia and Tasmania.
A 2021 review assessed the antiviral properties of Eucalyptus EOs. According to the review, Eucalyptus oil contains compounds called monoterpenes that bind with proteins on the surface of viral cells.
This binding impedes the ability of the virus to enter the host’s cells. Without this ability, the virus cannot replicate itself.
The review adds that Eucalyptus oil has properties that may help treat the symptoms of viral infections. These include:
- anti-inflammatory properties
- mucolytic properties, meaning it can break up and thin mucus so that it is easier to expel from the airways
- spasmolytic effects, meaning it helps to relieve muscle spasms
The review concludes that Eucalyptus oil and its major monoterpenes have great potential to prevent and treat viral diseases.
Like eucalyptus, tea tree also contains high amounts of terpenes.
A 2021 review notes that tea tree contains two terpenes called “Terpinen-4-ol” and “α‐terpineol” that demonstrate antiviral activity.
People have used thyme essential oil in
This is because of the suspected anti-inflammatory, antiviral, antibacterial, and antiseptic properties of thyme.
According to a
The researchers also observed that thyme EO displays some antifungal and anti-parasite properties.
A 2020 review lists peppermint oil among five of the most important antiviral herbs for cold and flu.
Peppermint contains the compound “menthol,” which is a common ingredient in over-the-counter cold and flu remedies.
A 2017 review notes that menthol can cause a cooling sensation in the throat, which may help to soothe the throat and airways.
A 2021 in vitro study investigated the antiviral activity of lavender and salvia essential oils against avian influenza (H5N1) virus.
In this study, both EOs demonstrated antiviral activity against the virus in a laboratory setting. However, further research is necessary to determine whether these oils are effective against viruses in living organisms, including humans.
Lavender is also widely renowned for its ability to promote sleep, which may prove useful for people struggling to sleep due to their flu symptoms.
Indeed, a 2017 study associated a herbal supplement containing lavender with subjective improvements in sleep quality among participants with mild to moderate insomnia.
A 2023 study investigated the effects of an aromatherapy oil blend on COVID-19 symptoms. The EO blend consisted of the following:
- lemon
- lavender
- peppermint
- tea tree
The researchers state they selected the above EOs due to their reported effectiveness against the following ailments:
- respiratory tract infections
- pain
- fatigue
- stress
Participants in the experimental group (EG) wore an aroma diffuser necklace during the daytime. The researchers instructed them to hold the diffuser close to their nose and inhale the EO blend for 1 minute, three times daily — in the morning, noon, and evening.
A control group (CG) received their usual care over the same 4-day testing period.
The study did not show any significant differences in nasal symptoms or stress between the two groups. However, the EG reported significant reductions in throat pain and fatigue compared to the CG.
The study authors concluded that the EO blend may help to alleviate sore throat in people with COVID-19.
It is possible that the EO blend may also help to alleviate sore throat from the flu, but scientists have yet to investigate this possibility.
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Of the 63 tested, 11 showed antiviral activity, and the most effective among these were:
- clary sage
- marjoram
- star anise
The researchers noted that all three of the above EOs contain linalool, so they speculated that this compound may be responsible for the anti-influenza effect. However, further research is necessary to establish whether this is the case.
A 2019 in vitro study investigated the antiviral effect of an EO blend consisting of oregano, thyme, and Greek sage on upper respiratory tract viruses. The study showed the blend to be effective against the following viruses:
- influenza A/H1N1 virus strains
- influenza B
- human rhinovirus 14 (HRV14)
In the case of influenza A/H1N1 and HRV14, the EO blend was associated with a decrease in virus replication.
The study authors concluded that the EO blend possesses antiviral activity and has the potential for use as an herbal treatment against both influenza viruses and rhinovirus.
However, further research is necessary to determine whether the EO blend is effective against viruses in human participants, and to establish an effective dosing regimen.
An older study from 2014 found that bergamot oil vapors and certain other EO vapors had an inhibitory action on the flu virus in vitro. This inhibitory action was primarily due to a compound in bergamot oil called “citronellol.”
A 2019 review also notes that bergamot and various other EOs have strong antiviral properties against the SARS-CoV-1 virus.
The study authors suggest inhaling these EOs via a diffuser or nebulizer could serve as a supportive treatment for SARS-CoV-2 (COVID-19).
It is not clear from this study whether inhaling bergamot would have similar therapeutic effects against influenza viruses.
A person should use bergamot carefully, as using too much can be toxic. There have been a few reports of bergamot oil causing the skin to be susceptible to sunburn when used topically.
A 2018 in vitro study found that cinnamon extract dampens the TLR2 and TLR4 signaling pathways involved in inflammation and that this effect is most likely due to two compounds in cinnamon called “rans-cinnamaldehyde” and “p-cymene.”
Influenza viruses
According to the
However, a person should contact a qualified healthcare professional if they experience flu symptoms and are at increased risk of flu-related complications.
This
Certain flu symptoms warrant emergency medical care. Anyone who experiences any of the
- shortness of breath or breathing difficulties
- persistent pain or pressure in the chest or abdomen
- persistent dizziness
- persistent confusion
- seizures
- lack of urination
- severe muscle pain and weakness
- a fever or cough that improves but then returns or worsens
- worsening of chronic medical conditions
Essential oils are plant oils containing natural chemicals or compounds, some of which may help to protect against the flu virus or treat flu symptoms.
Research into the effectiveness of essential oils against flu mainly uses in vitro studies, meaning it is difficult for scientists to determine how these substances will work against the flu virus in humans and other living organisms.
A person who is considering using an essential oil should first contact a qualified healthcare professional to determine whether the oil is suitable for their use.
Some essential oils are toxic if ingested, and some cause irritation when applied to the skin. Always keep them away from pets and children.
They may also interact with other medications or supplements a person is taking. As such, a person should enquire about an essential oil before using it for the first time.