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Natural Antivirals and Immune Boosters

Updated: Feb 5, 2023

With Cornavirus on the tip of everyone’s (proverbial) lips at the moment there is a general feeling of fear and lack of control on a global scale which is to put it mildly, is quite terrifying when we don’t know the outcomes or what we can do about it.

There are obviously no scientific studies on exactly what might be effective against COVID-19 as we simply have not had the time to explore this in depth.

In naturopathic medicine however, we look at the body in terms of how well we can support our immune system to fight off pathogens such as virus’ to reduce risk and we do know that those with lowered immune systems are the ones who are most likely to be affected.

With this in mind, there is plenty of solid research into natural antivirals that theoretically can be applied.

Vitamin C

Vitamin C is a well known antiviral agent, shown in studies to be effective against several virus’ such as influenza and herpes. It has been found to inactivate the RNA and DNA of virus’, rendering them unable to replicate and grow. It also enhances several of our immune cells - including cytokines, NK cells, B cells and T cells allowing our bodies to target and remove viral cells from the body.

Humans are one of the only mammals who do not produce our own vitamin C (along with guinea pigs, bats and dry nosed primates) due to a mutation in the GULO gene. It is hypothesised that this evolutionary mutation occured due to our ability to consume high amounts of vitamin C in our diets.

Foods high in vitamin C include citrus fruit, kiwi fruit, capsicum, greens vegetables, mango, pineapple, lilypilly, amla berry, camu camu and rosehip among others.

Supplementary Vitamin C doses vary from person to person - however a generalised dose of 2g daily for adults has been shown to have a therapeutic effect on the immune system.


Zinc is well known for its immune enhancing properties, and also has a host of studies backing it’s antiviral efficacy. Zinc-deficient populations are more at risk of acquiring HIV and Hepatitis C, and therapeutic use against Influenza and herpes has also been demonstrated via similar actions to Vitamin C - by enhancing our immune defence cells to do their job and keep us protected.

Zinc is found in higher amounts and is more bioavailable in animal sources such as oysters, fish and meat, as well as eggs and to lesser extents in nuts and seeds, grains and legumes.

Zinc supplementation for adults is recommended at 15-50mg daily, with prefered forms being zinc biglycintate, zinc glycinate, zinc citrate, zinc picoliante or zinc amino acid chelate. Many cheaper brands of zinc may contain zinc sulphate which is not as well absorbed.

Always take zinc with a meal or on a full stomach as it will make you feel nauseous on an empty tummy.

Herbal Antivirals


Echinacea spp. is a classic antiviral herb with a particular affinity for respiratory virus infections, especially against membrane containing virus’ (Coronavirus is membrane contained, and a respiratory virus). It has been shown to be effective against both human and avian virus’ (including a Tamiflu resistant strain) as well as herpes simplex virus, respiratory syncytial virus, over 100 rhinoviruses and certain adenovirus. It is one of the wider studied medicinal herbs, not only among adults, but also children.


Baptisia titoria is a lesser known medicinal herb which unfortunately has not had the homage of any clinical studies being carried out. It has however been shown in vitro studies to stimulate immune cells including lymphocytes and macrophages and has hundred of years of traditional use specifically against respiratory illnesses such as tuberculosis, pneumonia and influenza.


Andrographis paniculata has gained a lot more attention over recent years, being commonly found alongside Echinacea in immune formulas. Particularly effective at the early acute stage of infection, it has also been shown to stimulate our immune cell function and has been demonstrated to inhibit Epstein Barr Virus and HSV.

For those concerned about the robustness of their immune systems, those wanting to travel and protect themselves, those wanting to support elderly relatives or the immunosuppressed, the above are easy to find in good health food shops and safe in most situations.

Caution for those taking antiviral medications, immunosuppressant medications and medication for HIV (check in with a professional first) and those with a complicated health history should also seek professional advice.

Hygiene precautions such as regular handwashing and staying at home if unwell are the other obvious first line preventative measures we should all be practising.

Our bodies are designed to defend themselves, and to do it well and with the right tools we can boost our natural defences.

Emma xx

References -

Webb AL, Villamor E (2007) Update: Effects of antioxidant and non-antioxidant vitamin supplementation on immune function. Nutrition Reviews 65:181-217

White LA, Freeman CY, Forrester BD, Chappell WA (1986) In vitro effect of ascorbic acid on infectivity of herpesviruses and paramyxoviruses. J Clin Microbiol. 24:527-531

Kennes B, Dumont I, Brohee D, Hubert C, Neve P (1983) Effect of vitamin C supplements on cell-mediated immunity in old people. Gerontology. 29:305-310.

Read SA, Obeid S, Ahlenstiel C, Ahlenstiel G (2019) The Role of Zinc in Antiviral Immunity. Adv Nutr. 2019 Jul 1;10(4):696-710. doi: 10.1093/advances/nmz013

Hudson J, Vimalanathan S (2011). Echinacea—A Source of Potent Antivirals for Respiratory Virus Infections. Pharmaceuticals (Basel). 4(7): 1019–1031.

Churiya O, Bunga Pongtuluran E, Rofaani T (2015). Antiviral and Immunostimulant Activities of Andrographis paniculata. HAYATI Journal of Biosciences. Volume 22, Issue 2,, Pages 67-72

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emma jacques

Women's Health

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