Echinacea is among the most popular immune-boosting herbs. Solid evidence reveals it can help prevent the common cold by strengthening the body’s immune defense. But how much do we know about its potential effects on the new coronavirus? Read on as we dive deep into the latest science to figure out whether it’s actually worth taking amid the current pandemic.
This article is for informational purposes only. The current coronavirus outbreak is an ongoing event and certain details may change as new information comes to light.
Does Echinacea Have a Role Amid the COVID-19 Pandemic?
Research Overview
Echinacea is among the most widely used herbal immune boosters in both North America and Europe. People traditionally use extracts from different echinacea species to help fight bacterial infections and the common cold [1].
If echinacea helps us build immunity to viruses that cause the common cold, it must also do the same for the COVID-19-causing coronavirus — right? Not so fast.
The 2019 coronavirus is extremely recent, and we are still lacking robust studies specifically related to it. No effective or FDA-approved products are yet available to treat or prevent it.
Thus, we’re currently lacking evidence to claim that echinacea can directly prevent or treat the new coronavirus, also known as SARS-CoV-2 or 2019-nCoV. In fact, no studies on echinacea and SARS-CoV-2 have been published so far.
Therefore, we can only look at studies that tested various echinacea preparations on genetically similar microorganisms, including other coronaviruses like SARS-CoV and MERS-CoV.
Based on its immune effects, echinacea may turn out to be a good general supportive and preventive measure for SARS-CoV-2, similar to how zinc is used for SARS-CoV. If so, echinacea is more likely to play a larger role in prevention, but it’s still too early to say.
Remember, the best preventive measures you can take against SARS‐CoV-2 are those of standard care: social distancing, hand washing, and avoiding touching your face.
The Latest Findings
Before we jump to the effects of Echinacea on immunity and various viruses in detail, one preliminary report (so-called preprint) still awaiting publication deserves special attention. Mainly, the authors of this study claimed that echinacea might be effective for preventing all coronaviruses, including the newly occurring SARS-CoV-2 [2].
The data brought up in the preliminary report should be taken with a grain of salt. Their findings remain inconclusive, unvalidated, and medically uncertain until it undergoes peer review.
This study, led by a team of Swiss scientists, investigated the effects of a standardized echinacea preparation called Echinaforce® against several coronaviruses in cells (HCoV-229E, MERS-CoV, and SARS-CoVs).
Echinaforce irreversibly inactivated one virus strain called human coronavirus or HCoV-229E. This strain is typically associated with milder, cold-like symptoms. We can’t claim Echinaforce will have the same effects on cells of the SARS-CoV-2 virus, which is behind the current epidemic.
In the same study, scientists also poured Echinaforce over most types of cells before exposure to HCoV-229E, but they didn’t manage to prevent infection. The only exception were respiratory cells, which were protected against infection caused by droplets of HCoV-229E, a lab scenario imitating a natural infection. With more research, this might hold value for the new coronavirus that needs to enter lung cells to cause serious damage [3, 4].
Lastly, high-dose post-infection treatment in the study only slightly reduced the spreading on the same virus. This suggests a potentially modest, if any, role of Echinacea once the virus has entered the body. Other studies we bring up further down in the post echo this finding.
Echinacea & SARS-CoV-2 Prevention: Useful or Not?
Prevention & Recovery from the Common Cold
Echinacea is perhaps best-known as a traditional remedy for the common cold.
Colds can be caused by many different viruses, including other types of coronaviruses. These are, however, not the same as the 2019 coronavirus [5].
The data on echinacea and colds seem conflicting at first. For example, one meta-analysis concluded that echinacea products are ineffective at treating but may help prevent the common cold [6, 7, 8, 9].
Despite mixed findings, most evidence is on the side of echinacea.
Standardized echinacea extracts likely slightly reduce common cold symptoms. This was the case with colds caused by rhinovirus, which amount to 10%-40% of the cases [7].
Another study of 282 patients points out that echinacea should be taken at the first symptom of a cold [10].
According to most studies, echinacea extracts also likely help prevent colds, shorten their duration by a day or two, and reduce painkiller use [8, 11].
Scientists believe that echinacea extracts may reduce cold symptoms by reducing inflammation and mucus in the airways. Airway inflammation–especially of cells that line tiny sacs in the lungs–is implicated in COVID-19, but echinacea has never been tested in COVID-19 patients [12, 13, 14, 15].
Immune & Anti-Inflammatory Effects
Echinacea is believed to promote overall immune function and reduce inflammation [16].
In mice and rats, echinacea extract increased lymphocytes and monocytes, two types of white blood cells involved in immune defense [17, 18].
Recent studies suggest that people infected with the new coronavirus may have low lymphocytes. Low lymphocyte count has also been associated with worse COVID-19 outcomes [15].
The Battle of Interferons & Echinacea: Helpful or Harmful?
The Effects of Echinacea
In a study of 6 adults, echinacea extract reduced inflammation and increased the production of interferon molecules (IFN-alpha) after 3 days [19].
In general, interferons help fight viral infections. But some viruses can also take advantage of the immune system, forcing it to over-produce interferons [20].
Recent studies emphasize that the interaction between the virus and the host’s immunity determines the outcome of SARS-CoV-2 infection [20].
Interferons have a major effect on your immunity. Not having enough interferons may lower immune defense, which makes it easier for the virus to invade the body [20, 20, 15].
When first attempting to enter the body, coronaviruses try to dampen interferon release. It’s at this initial infection point that interferon-boosting compounds like echinacea might be useful [20, 15].
Can Echinacea Worsen “Cytokine Storms”?
Once coronaviruses enter the body, they force the immune system to mass-produce inflammatory molecules. Cytokines lose control and start damaging tissues, setting off a “cytokine storm” — the turning point that makes infection serious [20, 15].
Too much interferon (type I IFN) causes lung complications in people with coronaviruses similar to the 2019 strain (SARS-CoV and MERS-CoV)[15].
Thus, interferon-boosters like echinacea might do more harm than good in people who are already infected with the virus [20].
Echinacea has antiviral activity against viruses that have membranes. These include [21, 22, 23, 24]:
- Rhinovirus
- Herpes simplex
- Influenza A and B
- Coronavirus
- Respiratory syncytial virus
Scientists believe echinacea might disrupt receptors that viruses use to spread; these receptors are found on the viruses’ membranes [24].
In test tubes, echinacea was less effective against viruses inside cells than against viruses outside cells. So, if a virus already managed to sneak inside a cell, echinacea may be powerless to reach it. If virus particles shed into fluids outside cells, echinacea might be able to catch them [24, 13].
In dog cells, echinacea extract also prevented the influenza viruses from binding to and entering cells [25, 24, 26].
This further stresses that echinacea may play the biggest role during initial contact with viruses [24].
However, this doesn’t mean that echnicaea can prevent catching a specific virus, even if it shows activity against a virus in a cell culture.
Effects on ACE2
If echinacea shows potential for preventing viruses from entering cells, might it affect the ACE2 receptor implicated in the current coronavirus pandemic?
To rewind, the SARS-CoV-2 virus likely enters human cells by attaching to the ACE2 receptor, which serves as an entry point for the virus. This receptor normally plays an important role in balancing the body’s fluids and blood pressure [27].
Yet, evidence is currently lacking to claim that echinacea can block the ACE2 receptor. Some cell studies suggest that it may be a weak blocker, while others didn’t find any effect. Its impact on ACE2 has never been confirmed in animals or humans [28, 29].
ACE2 receptors can be found in the body’s airways, making them a target for several types of viruses. Recent research suggests that SARS-CoV-2 mainly causes serious respiratory complications by infecting the lungs via ACE2 [3, 4].
Since echinacea likely doesn’t affect ACE2, it may have a more important role in prevention. By ensuring proper immune defense, echinacea may help reduce one of the biggest risk factors for severe COVID-19: poor innate immunity in the elderly. This has yet to be tested, though.
Influenza
In a clinical trial on 473 people, a hot drink with echinacea was as effective as an antiviral drug (oseltamivir) at improving early flu symptoms [30].
Clinical research also shows that taking echinacea might improve the response to influenza vaccines in people with respiratory problems such as chronic bronchitis or asthma. These groups seem to be particularly vulnerable to COVID-19 complications [31].
An extract from echinacea and black seed also enhanced the immune response in stressed chicken vaccinated against bird flu. More research is needed [32].
Cough & Recurrent Respiratory Infection
A meta-analysis found that echinacea reduces the risk of recurrent respiratory tract infections and their complications [33].
Viral infections in the airways increase the chances of secondary bacterial infections that may cause pneumonia, bronchitis, and sinus and ear infections.
In the lab, echinacea extract made bacteria (Haemophilus influenzae and Staphylococcus aureus) stick to cells less while reducing cytokine storms. This hints at its potential to reduce respiratory complications [34].
However, we have yet to see whether echinacea can reduce respiratory complications in people with COVID-2019.
Dosage & Precautions
Dosage
Studies used a standardized liquid echinacea extract (Echinaforce) for the prevention of colds at the following dosage [35]:
- 0.9 mL three times daily (2400 mg echinacea daily) for 4 months for prevention
- An increase to 0.9 mL five times daily (4000 mg echinacea daily) at the first sign of a cold
The typical dosage for echinacea powders (including capsules) taken by mouth is 300mg-500mg three times per day.
Tinctures are usually used at up to 10mL daily, depending on the strength.
The optimal doses remain uncertain, and a lack of standardization among various extracts is a big problem.
Precautions & Side Effects
Most available supplements are composed of multiple echinacea species. The composition of these supplements can vary depending on which species were used and which parts of the plant were included (stem, flower, extracts). Therefore, echinacea supplements purchased from different sources can have varying health outcomes for the body [24].
According to data from clinical trials, side effects from echinacea consumption are rare. The common adverse reactions seen include rash and mild stomach problems such as nausea and stomach aches [36, 9].
Allergic reactions may occur, especially in people allergic to other plants of the same family (such as chamomile) [36].
Due to the effects of echinacea on immune function, people with autoimmune or systemic diseases like tuberculosis, multiple sclerosis, or AIDS should not use echinacea. This also applies to patients taking immunosuppressants [36].
Use of echinacea during pregnancy and breastfeeding is not recommended without consulting a doctor [37, 38].
Takeaway
Echinacea might be a useful herbal remedy for preventing and shortening the duration of the common cold. However, there is no solid evidence to support its use amid the current SARS-CoV-2 pandemic.
Echinacea is an immune booster: it seems to increase different white blood cells that fight infection.
This herb may also increase some potentially inflammatory messengers like interferons. In theory, this might be useful for prevention and during the initial stages of a viral infection. On the other hand, it may be detrimental to people with advanced COVID-19, the disease caused by the SARS-CoV-2 virus.
Early studies suggest that echinacea has the potential to play a role in SARS-CoV-2 prevention, but far more research is needed.
Due to a lack of proper clinical data, we don’t recommend the use of echinacea during the current coronavirus outbreak.
