Echinacea may slightly reduce your chance of catching a cold, but the evidence that it shortens a cold once you have one is weak and inconsistent. A Cochrane review found that some echinacea products had small preventive effects, while results varied hugely between species, plant parts and preparations. It is generally safe for short-term use, except for people with daisy-family allergies or autoimmune conditions.
Key takeaways
- Three species are used: Echinacea purpurea, E. angustifolia and E. pallida.
- A Cochrane review (2014) found possible small preventive effects but no consistent benefit for treatment.
- Products vary enormously – choose a standardised E. purpurea aerial-part extract.
- Use it short term (up to 10 days for treatment or 8 weeks for prevention).
- Avoid with ragweed allergy, autoimmune disease or immunosuppressant drugs.
What is echinacea?
Echinacea, also called purple coneflower, is a genus of daisy-family plants native to the prairies of North America. Plains tribes including the Lakota, Cheyenne and Comanche used the roots for wounds, snake bites, toothache and infections long before European settlers arrived. By the early 20th century it was one of the best-selling remedies in the United States, and today it is one of the top-selling herbal supplements in both the US and Europe.
The garden coneflower you may grow in your border is usually Echinacea purpurea, the same species used in most supplements.
How is echinacea supposed to work?
Echinacea contains alkamides (which cause the tingling feeling on your tongue), caffeic acid derivatives such as cichoric acid, and polysaccharides. Laboratory studies show these compounds can stimulate immune cells and have antiviral effects. The challenge is translating this into meaningful benefit in people.
What the evidence says
| Question | Finding |
|---|---|
| Does it prevent colds? | Pooled data suggest a possible relative risk reduction of roughly 10–20%; individual trials mostly not significant |
| Does it shorten colds? | No consistent benefit across trials |
| Does it reduce severity? | Mixed; some products show small effects |
| Is it safe short term? | Yes, for most adults |
The 2014 Cochrane review analysed 24 randomised trials with more than 4,600 participants. The authors concluded that echinacea products had not been shown to provide benefits for treating colds, although weak positive effects might exist for prevention. A large US trial published in Annals of Internal Medicine in 2010 found that echinacea shortened colds by about seven to ten hours on average – a difference most people would barely notice.
Choosing an echinacea product
Because preparations differ so much, product choice matters:
- Species: most research supporting benefit used E. purpurea.
- Plant part: aerial parts (leaves, flowers, stems) or the root; pressed juice of aerial parts has been well studied in Europe.
- Standardisation: look for products that state alkamide or cichoric acid content.
- UK buyers: look for the THR (Traditional Herbal Registration) mark, which guarantees quality and safety information, though not proven effectiveness.
How to take echinacea
- For a cold: start at the first sign of symptoms and take for up to 10 days.
- For prevention: some trials used continuous dosing for up to four months, but most guidance suggests no more than 8 weeks at a time.
- Tea: 1–2 g dried root or herb steeped in hot water for 10 minutes, up to three times daily.
Side effects and who should avoid it
- Allergic reactions: rashes, worsening asthma and, rarely, anaphylaxis – especially in people allergic to ragweed, chrysanthemums, marigolds or daisies.
- Autoimmune conditions: because it may stimulate immunity, avoid with lupus, MS, rheumatoid arthritis or similar conditions.
- Immunosuppressants: may counteract medicines given after transplants.
- Children under 12: the UK MHRA advises against use in children under 12 because of the risk of allergic reactions.
- Mild side effects: stomach upset, nausea, dizziness and an unpleasant taste.
Better-proven ways to handle a cold
The NHS recommends rest, fluids, paracetamol or ibuprofen for aches, and gargling salt water for a sore throat. Hand-washing remains one of the most effective ways to prevent colds. Warming drinks such as ginger tea and elderberry syrup are comforting, but none is a cure.
Frequently asked questions
Does echinacea help you get over a cold faster?
The evidence is weak. Large reviews have not found a consistent effect on cold duration, and one major trial found it shortened colds by less than half a day on average.
Can I take echinacea every day?
It is not recommended to take echinacea continuously. Most guidance suggests no more than eight weeks at a time for prevention.
Is echinacea safe for children?
The UK MHRA advises that echinacea should not be given to children under 12 because of the risk of allergic reactions.
Which type of echinacea is best?
Echinacea purpurea, particularly standardised extracts of the aerial parts, has the most research behind it.
Does echinacea interact with medications?
Echinacea may interact with immunosuppressants and some drugs metabolised by the liver. Check with a pharmacist if you take regular medication.
Sources and further reading
- Karsch-Völk M et al. (2014) Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews.
- NCCIH – Echinacea
- Barrett B et al. (2010) Echinacea for treating the common cold: a randomized trial. Annals of Internal Medicine.
- NHS – Common cold
