Last updated by Dr Sarah Brewer on
Echinacea is a traditional remedy that helps to prevent and treat colds. Also known as Purple Coneflower, it was first used by Native American Indians, such as the Sioux, to treat blood poisoning, snake bites, boils, fever, eczema and to relieve allergic reactions.
This attractive, perennial member of the daisy family is among the most important immune stimulants used in Western herbal medicine. Within the UK, Echinacea falls under the Traditional Herbal Registration scheme and is licensed as a traditional herbal medicine to help relieve symptoms of the common cold and influenza.
How does Echinacea work?
Echinacea contains several unique substances such as echinacoside, which have an antimicrobial action, and others such as echinacin B, which damp down inflammation and swelling. Its most potent action is in boosting the activity of circulating white blood cells responsible for attacking infections – whether viral, bacterial or fungal. Extracts improve the rate at which white blood cells ingest infected material, and boosts the production of a natural anti-viral substance called interferon, which interferes with viral multiplication. Echinacea is also highly antioxidant which helps to damp down the inflammation associated with infections.
Three main species are used medicinally: Echinacea purpurea, Echinacea angustifolia and Echinacea pallida. While the roots were originally used, modern products usually include the whole herb as the juice, fresh leaves and flowers contain the highest level of active ingredients.
What is the evidence that Echinacea is effective against colds?
Studies show that taking Echinacea almost doubles the length of time between infections compared with those not taking it and, when infections do occur, they tend to be less severe. Data from 14 Echinacea studies, involving almost 3,000 volunteers, included some who already had cold symptoms and some who were deliberately exposed to cold viruses. The combined results showed that taking Echinacea decreased the odds of developing a cold by 58%, and shortened the duration of a cold by 1.4 days. This Echinacea data was reviewed on the U.S. National Library of Medicine who concluded that the evidence presented appeared reliable.
Negative studies relating to Echinacea have gained a lot of publicity, but these often use inappropriate preparations. The strongest evidence for effectiveness against colds comes from studies using Echinacea purpurea. Studies using extracts of Echinacea angustifolia and those using dried leaves and roots have shown weaker results as the active ingredients are mainly concentrated in the juice. For example, one study used an extract consisting of 25% dried leaves from Echinacea purpurea and 75% dried roots from E. purpurea and E. angustifolia. The authors even admitted at the end of the paper that their dried mix of unrefined Echinacea has not been tested previously ‘and may be ineffective because of its bioavailability or phytochemical constituents’. This, of course, was rarely reported alongside the negative findings in the press. Another flaw in this Echinacea study was that the placebo, which should be inactive but was, in fact, 333mg alfalfa which is itself an herbal medicine used to treat allergies and nasal inflammation. If the trial had used fresh or dried juice Echinacea extracts rather than dried leaves or root extracts, the results would likely have been more positive.
Candida and Echinacea
When 60 women with recurrent vaginal Candida infections were given either a prescribed anti-fungal cream (econazole) or the cream plus oral Echinacea, 60% of those using just the cream experienced a recurrence within 6 months, compared with only 16 percent of those also taking oral Echinacea. This is an interesting example of a beneficial herb-drug interaction!
Check manufacturers’ instructions as different Echinacea products contain different extract concentrations. Many preparations contain one, two, or even all three medicinal Echinacea species so the dose and effectiveness differs from one product to another.
Typical doses from adults and children from the age of 12 are:
Tablets: 176mg of dried pressed juice equivalent to 3,520mg – 4,925mg of fresh flowering Echinacea purpurea, once or twice a day, to treat cold symptoms.
Tincture: 1 to 5 ml, three times a day.
Select products that are licensed as traditional herbal medicines, or which are standardised to contain a guaranteed level of active ingredients (eg 3.5% echinacosides).
Use Echinacea if you want to take a preventive treatment to boost immuinty against the common cold. If symptoms strike, however, I’ve found Pelargonium more effective as it typically produces a significant improvement within 24 hours.
Can you take Echinacea long-term?
Yes. Echinacea can be used in a lower dose, long-term, to reduce infections, or in high dose just when you feel an infection coming on. Overall, studies suggest that the incidence of a common cold infection is reduced by around 30% in those taking Echinacea for prevention. Where Echinacea is started after symptoms develop, symptoms improve twice as quickly as when not taking Echinacea.
However, opinions on how to take it do vary. Some ‘experts’ recommend that Echinacea is only taken for ten-days, although there is no scientific evidence to back this up. The white blood cells on which Echinacea acts only survive in the circulation for a short period of time, so they are unlikely to adapt to its presence, and long-term treatment is unlikely to become less effective over time (a phenomenon known as tachyphylaxis).
The manufacturer of one leading Echinacea tincture do not place any restriction on its long-term use, and say it may be taken in low dose, long-term, to reduce infections, or in a higher dose just when you feel an infection coming on. Other manufacturers prefer their products are used intermittently – for example, no more than two weeks without a break. However, there is no evidence of harm from taking it long term.
Even so, always follow manufacturer’s guidelines on how to use their products. Some will contain a different balance of ingredients to others which means they should be used in a different way.
Echinacea normally causes a tingling or numb sensation on the tongue. This is not harmful and quickly disappears.
Allergic reaction to Echinacea has been reported, although these are rare. Even so, it is no longer advised to give Echinacea to children under the age of 12.
Do not use Echinacea if you are pregnant, breast-feeding or if you have an autoimmune condition such as lupus and multiple sclerosis except under the advice of a medical herbalist.
Long-term oral use for up to 12 weeks produced no serious side effects in some studies, but headaches, dizziness, fatigue, and abdominal upsets have been reported in others. These side effects didn’t last long, and none were serious.
Image credits: ulla4you/pixabay; jenny_lee_silver/flickr