6 Effective Antiviral Herbs in Your Kitchen and their Properties

Last month I wrote about my search for evidence of the antiviral properties of simple kitchen and garden ingredients against coronavirus. While nothing that I suggest should substitute for getting proper medical care if you are ill, I am fascinated by the steps that we can take that prevent us getting so sick that we need medical care. In Coronavirus in the Kitchen: Part 1 I described my search methods and early results - including black cumin, chamomile, orange, fish mint, garlic, liquorice, rose, turmeric and saskatoon.

Here are some more commonly available plants to make your own kitchen remedies from, to increase your ‘pestilence resilience’. I’ve added references for the journal papers that support my findings at the end, along with a request for your feedback. Don’t miss that.


Lady Ellhorn the wise elder tree yields many crops: the berries, the flowers, the leaf and stem, and a strange gelatinous mushroom shaped like an ear - the wood ear (Auricularia auricula-judae). The berries of Sambucus nigra made into an extract have been shown to prevent people catching a range of common flu viruses both in real life and in vitro lab tests. A study also found that it can inhibit infectious bronchitis virus (IBV) - a chicken coronavirus - at an early point in the infection, probably by rendering the virus non-infectious. As it tastes great, it is often used as a family medicine to prevent coughs, colds and flu especially as the kids go back to school. It also fires up your immune system. This suggests that it is helpful as a preventative to keep your immune system healthy and prevent the start of a virus. However, if you have already caught a rapidly developing coronavirus infection, you should avoid using the berry extract. This is because one of the features of Covid-19 is that your immune system can go into overdrive, so added stimulation of your immune system could be harmful.

Other parts of the elder, such as the leaf, bark and stem have antiviral properties without the immune stimulation. In a recent screening of plants for activity against human coronavirus, a tincture of elder stem displayed strong anti-HCoV-NL63 potential. The researchers thought that a naturally occurring compound called caffeic acid could be the vital component with anti-HCoV-NL63 activity. A branch tip extract of a related red elderberry (Sambucus racemosa) known as the European elder also showed strong anti-coronavirus activity.

You can make a tincture at home by soaking the chopped leaves or stems in vodka for three weeks, at a ratio of 1 part chopped herb to 3 to 5 parts of vodka. UK herbalists tend to use a 1:3 ratio while USA herbalists favour a 1:5 as their tradition. HOWEVER, it is very important to remember that elder is highly emetic. This means that, unless you cook it first, its irritating toxins will make you vomit severely with painful stomach cramps. So you should only ever take small drop doses.

To avoid emesis - the vomiting effect - I simmer 1 part of leaves or chopped twigs in 2.5 parts of water by bringing it to boiling point and then simmering it, with the lid on to prevent evaporation, for a further 20 minutes. I then take it off the gas, add 2.5 parts of vodka, and leave it to infuse for four weeks to make a 1:5 extract. This ensures that no one is going to feel sick taking one teaspoonful three times a day. An uncooked tincture will remain emetic and should only ever be used in tiny doses, its advantage being that - like many other emetic expectorants - it may help to cough up mucus from the lungs. This is where going to see a qualified herbalist can really help to keep you safe.

The berries, for pre-infection immune support, can be boiled to release their juice that is then strained, and sugar or honey is added to make up 30% of the volume. Brought to the boil once the sugar has dissolved, and simmered for a final 5 minutes, will give you a lovely syrup when cool. I prefer to simmer the juice with other herbs and spices that reduce inflammation, increase immune system modulation (to prevent cytokine cascades), and add additional antiviral herbs and spices. This is exactly the formulation approach that I took when my friend Rupert Waites at Buck and Birch had a glut of elderberries and we made a Wild Elderberry Elixir for Napiers.

Blue Jean Baby

The phenolic compounds from dyer’s woad (Isatis indigotica) have also been screened and showed anti-coronavirus powers. Woad was once commonly grown for its lovely indigo blue dye colour but has gone out of fashion since chemical dyes took over. I know that in Victorian times, arsenic green wallpaper would make people very sick from contact with it, brushing against it or inhaling particles, so I’ve toyed with the idea of ‘woad wallpaper’ to keep coronavirus out of the house or perhaps some anti-covid blue jeans? (Just kidding!)

The Mighty Oak

Quercetin and tannic acid were also candidates for new drugs. They both originally come from Quercus species, the oaks. Quercetin is an interesting compound that’s been widely available as a supplement for years and is mainly used to dampen down high histamine and overactive mast-cell response in people with hay fever or food allergies. Tannic acid in oak bark was of course once used to tan leather, drying it out and giving it its rich dark brown colour. Tannins are also found in tea and gives mugs their brown stain over time!

Having been a custodian of Victorian herbal medicine for a long time, it’s interesting to remind people that oak bark was often added to traditional remedies for the flu. I know one recipe of elder flowers, peppermint and oak bark that was a ‘composition essence’ to help sweat out and dry up an infection. One of the problems in coronavirus infection is when the immune system becomes over-reactive and this is where a course of a quercetin supplement could help if you are someone already suffering from hay fever or allergies.

A Nice Cuppa Tea

Black tea came up trumps in studies too. Perhaps it was all those tannins! So now is the time to give coffee a break and invest in some lovely organic loose teas. If you’ve only ever stuck to builders’ tea bags you’ll be amazed how many different varieties and flavours there are out there.

Birch Trees & Their Fungi

Betulinic acid is an interesting compound found in birch trees (Betula spp.) and the medicinal fungi that live on them, birch polypore (Piptoporus betulinus) and chaga mushroom (Inonotus obliquus). Birch leaf tea was once regularly drunk by gardeners and others with a sore back or stiff joints to alleviate pain and reduce inflammation - they also contain methyl salicylate one of Nature’s aspirin compounds. Birch is also antimicrobial and containers, made from birch bark, were used by our ancestors as a type of Stone Age Tupperware to keep food from going off - well at least to slow down the decay. As betulinic acid is now found to be antiviral for coronaviruses, perhaps it’s time to ditch paracetamol for a cup of birch leaf tea next time you’ve overdone the exercise.



The Wormwood Family

Several Artemisias from the wormwood family managed to get included in the screening. This doesn’t surprise me as Sweet Annie Artemisia annua is well known as an antimalarial. There are several other species too that grow in British gardens and run wild. Wormwood Artemisia absinthium a traditional ingredient of absinthe - a potent alcoholic drink that in Victorian times could make you crazy (although that may well have also been methanol in poorly distilled cheap alcohol). Southern wood Artemisia abrotanum traditionally used as a worming medicine and of course Mugwort Artemisia vulgaris, a highly valued shamanic herb that makes dreaming more vivid and lucid, and also brings calm.

Artemisinin is extracted to make a drug, now with some semi-synthetic derivatives. Once hailed as a break-through antimalarial it really is a lesson for our time. However, like so many modern drugs it has been outwitted by the organism it targets and malarial resistance has set in and the drug companies are trying various combination compounds to combat this.

Yet, last year I was at a Cryptoinfections Conference in Dublin listening to a very interesting presentation of a clinical trial done in East Africa with a simple, home made tea of Artemisia afra. This species not only stopped the malaria in patients but was also discovered not to contain any artemisinin! So why is it that organisms become resistant to drugs but not plants?

We are not the only clever species on this planet. Intelligence is all around us in all living organisms and the systems that make up Gaia, and life is constantly evolving, responding, reacting and reinterpreting. For living things without a much-coveted ‘brain’, plants have developed as master chemists and fungi as master alchemists. Plants have been analysing their surroundings through their multiple ‘noses’ (scent receptors on the surface of every cell on their stems, trunks and branches), for over 400 million years. Every breath in the forest is analysed and not even the lightest of breezes ruffling the grasslands goes unnoticed.

Contrary to common public opinion, plants are not passive, indeed they are highly active and responsive to their environment. Their inability to uproot and run away from trouble means that they have to face up to every threat and challenge. And deal with it, disabling, disarming, where necessary destroying, to restore harmony and equilibrium around them. O if only humans were so rooted in the earth. Imagine if we couldn’t run away, move house, emigrate, join a different society, pass the buck, drive away from landfill, make toxic goods in poorer countries or retreat to a gated community… perhaps we too would invest as passionately in our environment as the plants do.

Never opting out, plants continue to use their chemistry expertise to change their environment. Their sheer complexity - each species containing hundreds of compounds - designed to respond to and modulate processes both inside them and in their habitat, results in living medicine for us. Literally alive. Bacteria and other pathogens are smart and a single chemical compound is easily out-witted, but plants are equally smart, chemically complex, and have lived alongside bacteria and viruses for over 400 million years. They have their measure!

To conclude in the words of the researchers Boukhatem and Setzer “Considering the significant number of traditional medicinal plants that have provided good outcomes, it would seem reasonable to assume that these [plant] products contain different types of antiviral compounds. A characterization of secondary metabolites will reveal further health benefits. Therefore, the common usage of many traditional medicines for the prevention of viral infections is warranted. Eventually, the discovery and development of new antiviral agents from medicinal plants and herbs to control the threats presented by certain pathogenic viruses, such as the 2019-nCoV, is critical.”

Next month - in Part 3 - I’ll be talking about Cinnamon, Reeds, Dock, Honeysuckle, Mulberries and Marigolds.

Further reading for all you boffins out there!

Boukhatem, M. N., & Setzer, W. N. (2020). Aromatic Herbs, Medicinal Plant-Derived Essential Oils, and Phytochemical Extracts as Potential Therapies for Coronaviruses: Future Perspectives. Plants (Basel, Switzerland)9(6), 800.

Chen, C., Zuckerman, D. M., Brantley, S., Sharpe, M., Childress, K., Hoiczyk, E., & Pendleton, A. R. (2014). Sambucus nigra extracts inhibit infectious bronchitis virus at an early point during replication. BMC veterinary research10, 24.

Fuzimoto, A. D., & Isidoro, C. (2020). The antiviral and coronavirus-host protein pathways inhibiting properties of herbs and natural compounds - Additional weapons in the fight against the COVID-19 pandemic?. Journal of traditional and complementary medicine10(4), 405–419.

Mani, J. S., Johnson, J. B., Steel, J. C., Broszczak, D. A., Neilsen, P. M., Walsh, K. B., & Naiker, M. (2020). Natural product-derived phytochemicals as potential agents against coronaviruses: A review. Virus research284, 197989.

Orhan, I. E., & Senol Deniz, F. S. (2020). Natural Products as Potential Leads Against Coronaviruses: Could They be Encouraging Structural Models Against SARS-CoV-2?. Natural products and bioprospecting10(4), 171–186.

Russo, M., Moccia, S., Spagnuolo, C., Tedesco, I., & Russo, G. L. (2020). Roles of flavonoids against coronavirus infection. Chemico-biological interactions328, 109211. Advance online publication. https://doi.org/10.1016/j.cbi.2020.109211

Shu-Jen Chang, Yi-Chih Chang, Kai-Zen Lu, Yi-Yun Tsou, Cheng-Wen Lin, "Antiviral Activity of Isatis indigotica Extract and Its Derived Indirubin against Japanese Encephalitis Virus", Evidence-Based Complementary and Alternative Medicine, vol. 2012, Article ID 925830, 7 pages, 2012.

Weng, J. R., Lin, C. S., Lai, H. C., Lin, Y. P., Wang, C. Y., Tsai, Y. C., Wu, K. C., Huang, S. H., & Lin, C. W. (2019). Antiviral activity of Sambucus FormosanaNakai ethanol extract and related phenolic acid constituents against human coronavirus NL63. Virus research273, 197767.

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***Content of this blog/website is for information purpose only. It is not intended to substitute for legal or medical advice, or medical treatment or diagnosis. Consult your health care provider if you are experiencing any symptoms and before using any herbal product or beginning a new health regimen. When wildcrafting or foraging for plants, do so ethically; be accompanied by an expert; and always have absolute certainty of plant identification before using or consuming any herbs. by using any or all of this information, you do so at your own risk. No warranties are expressed or implied. Any application of the material provided is at the reader’s discretion and is his or her sole responsibility.

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