Echinacea is the name of a group of flowering plants that are native to North America. Consumers of echinacea believe that the supplement boosts the immune system and can reduce symptoms of infections and other illnesses, including the common cold.

In previous in vitro studies echinacea purpurea has been shown to have strong antiviral activity against enveloped viruses. After the onset of Covid-19, expanded studies demonstrated that the anti-viral benefits of echinacea also worked against SARS-CoV-2.

Echinacea purpurea is one of the three species of echinacea that are known to have therapeutic properties.

Now the results of a new randomized controlled trial has shown the potential of echinacea in preventing and treating SARS-CoV-2 infections using healthy human volunteers. A randomized controlled trial is the most scientifically rigorous method of hypothesis testing available.

Though results were only published in 2022, the study was carried out at the height of the Covid pandemic—from November 30, 2020 to May 29, 2021.

Study details

A total of 120 volunteers were provided five months of supplementation with 2,400 mg per day of an echinacea purpurea provided by a supplement manufacturer in Switzerland.

All test subjects were seen and tested at a single test center, the Diagnostics and Consultation Center Convex in Sofia, Bulgaria.

Subjects had to provide nasal or oral swabs, in addition to blood samples, on a monthly basis for the purpose of virus detection and quantification. If diagnosed with acute symptomatic episodes they also had to provide samples on days one, two, five and 10. They were also required to complete a symptom diary to establish severity of respiratory symptoms.

Samples identified 21 positive cases in the echinacea group and 29 positive cases in the control group. Of these, five and 14 samples tested positive for SARS-CoV2 respectively.

Study results

Echinacea was shown to be effective against all viral types observed, but was more effective for coronavirus infections.

There was a 25% reduction of all respiratory viruses, increasing to 43% for enveloped viruses, and 48% for coronavirus infections.

Researchers also reported that higher dose of echinacea administered during acute respiratory tract infection was even more effective. When administered this way there was a 99% reduction in viral loads.

According to researchers this suggested that there was a limited ability of respiratory viruses to evade the antiviral effects of echinacea.

“A commercial preparation of echinacea purpurea in the licensed dosage represents a safe, easy-to-use and widely available cost-efficient antiviral with effects in preventing respiratory tract infections, including SARS-CoV2 and reducing virus load. It may add well to existing counter measures in the current Covid-19 pandemic,” the scientists wrote in the study summary.

The study was published in Frontiers in Pharmacology in June 2022.

Echinacea basics

Historically echinacea exhibits broad antiviral and antifungal effects in both adults and children. This effectiveness includes coronaviruses, including the yearly flu.

The protective properties seem most clear with echinacea purpurea, which also appears to be the strain with the most research. Echinacea purpurea has repeatedly been shown to reduce inflammatory cytokines while at the same time increasing anti-inflammatory cytokines that respond to invading pathogens.

Weighing in on the study, the American Botanical Council noted that though the study has limitations, the results conform with previous findings and further substantiates the inherent preventative qualities of the herb.

“I hope manufacturers may take a closer look at echinacea as an ingredient, and possibly invest more resources into clinical studies, which may lead to more confidence by consumers about the benefits of their product and therefore increased sales,” said Dr Stefan Gafner, Chief Science Officer at the American Botanical Council.

During the Covid pandemic, Echinacea has been one of the most trusted herbs that consumers turn to in order to boost the immune system. According to a survey by the American Botanical Council, echinacea sales increased by 36.8% during the first year of the pandemic. It was one of four herbs that saw an increase surpassing 30%.

Echinacea purpurea is part of the potent immune-building blends found in the following Optimal Health Systems products:

• Optimal Defense
• Natural Z Pak
• Opti-Immune VRL

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Sources: Frontiers in Pharmacology, American Botanical Council.

To learn more about echinacea, see our article Introduction to Echinacea — America’s favorite immune building herb.