Antiviral plant medicine 

Denise Cox explores the antiviral properties of plants, particularly in the forms of essential oils and tinctures.  

This information is not intended as medical diagnosis or prescription. Please contact your healthcare provider if you feel unwell or have symptoms of covid-19. 

Cautionary notes
Herbal medicines and essential oils may interact with pharmaceutical medicines. Seek medical advice before using on children, when pregnant or if you have pre-existing medical conditions. Do not ingest essential oils. Use them in small quantities and dilute with a suitable carrier oil.  

Todays pharmaceutical industry is a relatively recent phenomenon, originating from Victorian apothecaries where drugs such as morphine were made from plant compounds, and early twentieth century dye and chemical companies who discovered medicinal uses from their byproducts. For millennia before that traditional medicine primarily used the properties of plants to treat or help prevent illnesses, including viral infections.  

Clinical research on the antiviral properties of specific herbs is limited, having been conducted in laboratory petri dishes, or animals, and may not have been tested on humans. However, chemical components within plants may disrupt the viral lifecycle and alleviate symptoms, for example, help relieve a cough, assist with breathing or sleep, improve recovery, or boost the immune system. 

Extraction of plant compounds 

Plant compounds are used therapeutically in several ways.   

  • Essential oils concentrate the properties of a specific plant, through methods including steam distillation, pressing or wax extraction. Blends of different essential oils combine and enhance the therapeutic properties of individual plants.  
  • Tinctures are concentrated herbal extracts made by soaking plant material in an alcohol or vinegar base. Tinctures make it easy to ingest the health-boosting chemicals in plants and are relatively cheap and easy to make.  
  • Fresh or dried plant parts can be eaten, made into teas or used as poultices. While beneficial theyre less potent than tinctures or essential oils.  

Using essential oils 
Essential oils can be used therapeutically to relieve symptoms caused by viruses in several ways.

  • Inhalation or vaporising to help with breathing, stress and sleep. Oils can be inhaled over a bowl of steaming hot water, directly inhaled, or placed on cotton wool balls or pillows.
  • Add oils to a diffuser, vaporiser or oil burner, to clean and freshen the air. 
  • Massage the body, chest, head, neck, feet or sinuses with essential oils diluted in carrier oils such as coconut, hemp or jojoba.  
  • Add oils to baths (some oils will damage plastic or enamel baths and irritate your skin). 
  • Some essential oils such as lemon myrtle are superb air fresheners or are diluted and used to clean surfaces. As some essential oils can dissolve paint and damage plastic and polished surfaces, its better to purchase proprietary brands.  


Make tinctures by submerging herbs in alcohol in a glass jar. Use only the parts of the plants that are safe to use: for example a plants leaves may be safe, but the seeds might be poisonous. Alcohols that are at least 8proof (40% alcohol by volume)efficiently extract plant compounds and are a stellar preservative.  

How to make a tincture  

  1. Finely chop fresh or dried plant material.  
  2. Sterilise a glass jar. 
  3. Fill the jar three quarters full with plant material. Pour alcohol such as brandy or vodka to the top of the jar, covering all plant material.  
  4. Put greaseproof paper over the jar top and screw on the lid. Store in a cool dark place for 6–8 weeks.  
  5. Drain and discard the plant material, using a sieve lined with muslin.  
  6. Bottle the tincture in glass containers. Label, date and store in a cool dark place until needed. 


A dropperful equals approximately 30 drops from a standard glass dropper. A standard suggested adult dosage for tinctures is 2 dropperfuls, two to three times a day.

16 plants with antiviral properties 

Many plants have antiviral properties – here are some common ones. These may be general or specific to a virus or viral strain. Their effectiveness may be enhanced by blending their essential oils with those from other plants.  

  1. Cinnamon bark has demonstrable antibacterial, antiseptic, anti-inflammatory qualities, and antiviral activity against viruses including avian flu H5, influenza A, parainfluenza virus, HIV and HSV-1 viruses. Studies show that cinnamon essential oil effectiveness against flu viruses increases when combined with eucalyptus and rosemary essential oils. 
    Applications: essential oilvaporiser, teas, culinary.
  2. Cloves have antiviral, antimicrobial, antiseptic and antifungal properties. Clove oil may increase the efficacy of the medication acyclovir, used to treat viral infections underlying Bells palsy, chronic fatigue syndrome anherpes simplex. Diffusing clove oil helps clean the air. Cloves relieve blocked nasal passages, sinus and lung congestion and soothe sore throats.
    Applications: essential oil, diffuser, culinary, tea, tincture.
  3. Eucalyptus has potent antibacterial and antiviral properties and is excellent to stimulate the immune system, treat respiratory problems, and reduce fevers. Aerosols made with eucalyptus and tree tree blends have shown high antiviral efficiency against influenza viruses
    Applications: essential oil, diffuser, tincture.
  4. Ginger demonstrates antiviral activity against colds and flu. Studies conducted on animals found ginger root had antiviral action against the avian flu and herpes simplex viruses.
    Applications: essential oil, diffuser, culinary tea, tincture.
  5. Lavender is one of the safest essential oils with demonstrable antibacterial, antiseptic, and anti-inflammatory properties, and antiviral activity against viruses including herpes simplex virus type 1. Lavenders scent promotes sleep and breathing which aids recovery.  Applications: essential oil, diffuser, room spray, culinary, tea, tincture.
  6. Lemon has antifungal, antibacterial and antiviral properties. Diluted lemon essential oil is useful for disinfecting the air and surfaces. It has numerous health applications, including stimulating the immune and digestive system and clearing the nasal passages.  Applications: essential oil, diffuser, tea, culinary, tincture.
  7. Lemon balm or melissa is a well-documented antiviral herb. Laboratory studies demonstrate antiviral properties against influenza, mumps, herpes and smallpox viruses
    Applications: essential oil, vaporiser, tea, culinary, tincture.
  8. Lemon myrtle has proven antiviral effects against Molluscum contagiosumIts anti-inflammatory and antimicrobial properties boost the immune system, and relieve sinus and bronchial infections. The essential oil is a useful antiseptic, disinfectant and expectorant and may be more powerful than tea tree. Excellent in diffusers to clean the air. 
    Applications: essential oil, diffuser, culinary, tea, tincture.
  9. Liquorice root: Test-tube studies show effectiveness against HIV, RSV, herpes viruses, and SARS coronavirus (SARS-CoV).
    Applications: tincture, tea, culinary.
  10. Mullein has antibacterial and antiviral properties and is a traditional remedy for relieving influenzas, colds and respiratory issues. Some laboratory studies have shown mullein to have antiviral activity against influenza A and herpes; another found combining the medication amantadine with mullein increased antiviral activity against influenza. Applications: tea, tincture, essential oil.
  11. Oregano has anti-inflammatory and antioxidant properties, and exhibits antiviral activity against numerous viruses including Murine norovirusOregano essential oil is different from the herbal supplement and shouldnt be taken orally. 
    Applicationsessential oil, diffuser, culinary, tea, tincture.
  12. Peppermint essential oil possesses antiviral, antibacterial and antiseptic properties and is a proven potent antiviral against the herpes simplex virus. Peppermint helps reduce coughs, sinusitis and throat infections. 
    Applications: diffuser, room sprayessential oil, culinary, teas, tincture. 
  13. Rosemary has antibacterial, antifungal, and antiviral properties and has shown antiviral activity in laboratory and animal tests against herpes, HIV, influenza, and hepatitis.
    Applications: essential oil, diffuser, culinary, tea, tincture.
  14. Tea tree (Australian tea tree, Melaleuca alternifolia, not manuka) has numerous antibacterial and antiviral properties. Test-tube studies show effectiveness against influenza, herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) 
    Applications: essential oil, vaporiser, room spray, tea.
  15. Thyme is a powerful anti-infectious agent and immunostimulant thats been scientifically proven to kill harmful bacteria, fungi and viruses, and was used to disinfect hospitals in World War I. Blends of thyme, eucalyptus and tea tree essential oils have been shown to reduce viral infectivity by more than 96%
    Applications: essential oil, vaporiser, tea, tincture, culinary.
  16. Turmeric: Research shows that turmeric has antiviral effects on influenza, hepatitis C and HIV viruses. 
    Applicationsessential oil, diffuser, culinary, tea, tincture. 


How viruses spread 

Viruses are hijackers that invade and multiply inside living cells. They can live on inanimate surfaces for more than 24 hours depending on atmospheric conditions and surface type.  

Viruses can spread by airborne droplets which transfer to a live host. Viruses cause infectious diseases including HIV, cold sores, warts, smallpox, ebola and flu. Different viruses will attack cells in specific parts of your body such as your blood, respiratory system or liver.  

Given the right conditions, viruses can transfer between species, then mutate as they evolve. A virus may mutate into many different strains, some more virulent than others, making them difficult to kill. 


Denise Cox is a writer, former organic grower in Kerikeri, and now co-owner of Lavender House Perfumery in Tasmania, which she is converting to organics (