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How Echinacea Works, Cold, Flu, Sinus Infection


Common cold is a leading reason children and adults stay home sick from school or work, according to the National Institutes of Health. It’s estimated that one billion colds are caught and spread in the U.S. every year. During influenza season, 35 to 50 million Americans get the flu. Flu outbreaks can sweep through entire communities, affecting up to half the population. For certain people (the elderly, newborns, and people with chronic illnesses) the flu can cause serious and even life-threatening complications. Echinacea, (pronounced eck-in-AY-sha) a safe and highly effective natural supplement, not only rapidly improves cold and flu symptoms, but can prevent these diseases. Most importantly, when echinacea is combined with two other herbs, white cedar and wild indigo, even greater health benefits can be achieved.,5

Why hasn't a "c-u-r-e" been found for colds and the flu?

Viruses are extremely difficult to study. To reverse a cold, a remedy would need to kill any one of the 200 different viruses. Flu viruses continually evolve and mutate from season to season.,2 So far, no one has succeeded at finding the magic formula for stopping cold or flu.

The best research has been able to offer is the development of over-the-counter (OTC) medicines to treat cold and flu symptoms. However, there is some consensus that treating the symptoms of colds and flu infections may actually prolong the duration of the disease and prolong the misery.,2 In addition, some potentially serious side effects have been associated with the use of OTC cold and flu medications.,9

What kind of side effects are associated with OTC cold and flu medications?

A variety of OTC products are available. Decongestants temporarily dry up runny noses, stop sneezing, and relieve watery eyes.

Acetaminophen, aspirin, and ibuprofen reduce body aches. Aspirin and ibuprofen bring down fevers.,2

All these medications can cause side effects. Aspirin and ibuprofen can cause gastrointestinal upset.,11 Additionally, aspirin should never be given to children and adolescents with colds or the flu. Several studies have linked the use of aspirin to the development of Reye’s syndrome, a rare and potentially fatal illness.,2

Taking acetaminophen over an extended length of time can cause liver and kidney damage so the daily dose should be limited to no more than four grams.2,13 Decongestants can cause high blood pressure, heart palpitations, urinary retention, nausea, vomiting, drowsiness, anxiety, tremors, and insomnia. Decongestant use can alter the normal tissue of the nose and actually increase the duration of nasal congestion.,16

However, suffering with an untreated cold or the flu can be very distressing and quite uncomfortable. Thankfully, there are natural supplements available that can shorten the duration and severity of both the common cold and the flu. Echinacea, white cedar leaf, and wild indigo root are some of the most popular cold and flu herbs.

Are herbal extracts really effective for colds and flu?

Echinacea is one of the most effective herbal remedies available. Not only do the extracts from this pretty purple coneflower treat common cold symptoms but prevent these infections after exposure as well.

Most importantly, echinacea extracts, combined with wild indigo and white cedar, can provide even greater cold and flu protection.,5

How was echinacea discovered to relieve cold and flu symptoms?

Echinacea, a member of the sunflower family, was first used by Native Americans to treat a variety of illnesses and injuries. Knowledge of the herb’s potent properties was passed on to white settlers who rapidly discovered its ability to relieve cold symptoms. Echinacea was quickly recognized as remarkably effective and, by 1920, American doctors prescribed echinacea more than any other medicinal plant preparation.

However, echinacea fell out of favor in the 1930s in the U.S. with the advent of sulfa drugs. Physicians saw little value in using a mere flower to reverse the effects of infectious disease when stronger remedies were being discovered every day.

While echinacea slowly gave way to antibiotics in the U.S., use of the herb to treat colds and flu remained steady in Europe, especially in Germany. German scientists, physicians, pharmacists, and chemists started to study echinacea’s properties and continue to do so today. Presently, there are more than 280 commercial preparations containing echinacea in Germany.

Additionally, the important discovery that combining white cedar leaf, wild indigo root, and echinacea for improved immune system health was made in Germany. These herbs have been in continuous use together since 1928 and have been studied in more than 15 clinical trials. Formulations of echinacea, white cedar leaf, and wild indigo root are available in Germany as a prescription drug as well as an OTC medication, and in the U.S. as a nutritional supplement.,5

Interest in herbal extracts re-emerged in the U.S. in the 1960s and echinacea soon gained a loyal following here. The research behind echinacea has been and continues to be impressive. Most importantly, when echinacea, white cedar leaf, and wild indigo root are combined for use against colds and flu, they work quite well.

Are different varieties of echinacea available?

Three varieties of echinacea are currently used in nutritional supplements. These are Echinacea angustifolia, Echinacea purpurea, and Echinacea pallid. The most studied varieties (and therefore, the varieties with documented beneficial effects) are E. purpurea and E. pallida.-23

How does echinacea, white cedar, and wild indigo work?

Because echinacea is so popular and effective, quite a bit of research has been performed to understand how this herb actually works. Simply stated, while antibiotics kill the disease-causing microbes, echinacea enhances the body’s own ability to fight off infections.

Research has discovered echinacea stimulates the production of important immune cells.,25 These cells—known as macrophages—engulf bacteria, viruses, and cellular debris, essentially acting as garbage collectors for the body. They are responsible for the body’s initial attack against invading viruses. Echinacea also helps macrophages work more effectively. In addition, echinacea enhances the function of monocytes, special blood cells that mature into macrophages.

Echinacea increases both the numbers of natural killer (NK) cells as well as NK cell activity.,29 These specialized immune cells are programmed to automatically kill cells infected with viruses.

Echinacea also increases the release of some important immune proteins, “tumor necrosis factor”(TNF), and the interferons.3 TNF regulates immune responses, mediates inflammation, and kills certain cancer cells.

Interferons are produced in response to an attack by a virus. White cedar increases TNF production ,32 and both wild indigo and white cedar increase macrophages and interferons.-37

Are there any safety concerns with echinacea, white cedar, or wild indigo?

The German Commission E notes that because of possible overactivation of the immune system, echinacea should not be taken by persons who have multiple sclerosis, lupus or other autoimmune diseases, tuberculosis, HIV, or AIDS. It should not be taken during pregnancy or by individuals who are allergic to plants of the sunflower (Asteraceae) family. The Commission E further recommends that echinacea should not be taken longer than eight weeks.,39 To date, there are no concerns for white cedar or wild indigo.

The 1999 American Herbal Products International Echinacea Symposium addressed issues regarding the safe use of echinacea preparations. An expert panel discussed the lack of evidence substantiating such caution. Much of the early echinacea research was performed on the European variety, E. angustifoliResults from this variety may not have application in other varieties. The consensus of the expert panel was that these warnings are based more on theoretical concerns than on specific scientific data and urged the continuation of controlled studies to confirm clinical efficacy.

How much echinacea, white cedar, and wild indigo should be taken?

For adults and children over 12 years of age, studies have shown the most effective dose of echinacea is 7.5 mg of a one-to-one (1:1) mixture of E. purpurea and E. pallida taken three times per day.,39 The most effective dose of white cedar leaf is 2 mg taken three times per day and wild indigo root is 10 mg taken three times per day.3

If family members or co-workers have an active cold or the flu and individuals hope to prevent infection, this same regimen can be followed. This dosing can continue for several days even if no signs of illness develop.3,38,39

How long should echinacea, white cedar, and wild indigo be taken?

Experts’ opinions vary; most recommend taking them for three to five days. If symptoms persist or recur then take them for another three to five days.,4,,39 The best advice is to take the herbs for different amounts of time when the immune system needs extra support.

Can children use echinacea and the other herbs for cold symptoms?

Yes, children ages 1 and older can safely benefit from these herbs. Doses for children should be adjusted to age and weight.,,39

What else can be done for colds and flu?

Supplementing with elderberry during the flu may reduce its symptoms. Elderberry is an herb that causes an increase in viral antibodies. While elderberry is available as an individual supplement, it is also frequently combined with other vitamins, minerals, glandular extracts, or herbs for maximum cold and flu symptom relief.

If you also have an irritated throat, English ivy extract has been shown to provide natural and effective relief. English ivy soothes and quiets coughs due to colds and flu without the side effects often found in some products containing synthetic ingredients.-44

Getting lots of rest and drinking lots of fluids (a minimum of 64 ounces of water and juice a day) are also very important. Drinking hot beverages such as tea and eating chicken soup are not only comforting, but they can open up stuffy noses. Gargling with salt water may help reduce painful sore throats.,2

Individuals should seek care from a licensed health care practitioner if they have a fever that lasts longer than three days, are coughing up yellow-green mucus, or have chest pain that occurs with breathing. These symptoms may signal more serious conditions.,2

With colds and flu, "an ounce of prevention is truly worth a pound of cure." Frequent hand washing and sneezing into facial tissues (that are promptly thrown away) are the easiest and most effective ways to prevent the spread of colds and flu.,2


Echinacea is the most widely used herbal supplement in the United States for good reason: it works. Combining echinacea with white cedar and wild indigo greatly improves the herb’s effectiveness. While a solution for colds and the flu may be years away, herbs such as echinacea, white cedar, wild indigo, elderberry, and English ivy extract can make this wait much more bearable. Together, these herbs can prevent, treat, and reduce the duration of these common viral illnesses.


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Decker Weiss

Author Decker Weiss is a licensed naturopathic medical doctor in the state of Arizona.

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Updated: July 6 2014