“Echinacea prevents colds.”
Echinacea does not reliably keep colds away; in pooled trials, people taking it were only slightly less likely to catch one.
Echinacea will not keep you from getting colds. Taken regularly, it lowers the odds by a small amount at best, and the result depends on the product. It is not worth counting on.
If you decide to try echinacea, use it only for short periods and stop if you get a rash, swelling or stomach upset.
Safety note: Some people have allergic reactions to echinacea, which may be severe. The plant is closely related to ragweed, daisies and sunflowers. The most common side effects are stomach problems such as nausea or stomach pain. Some children in a trial developed rashes that may have been allergic. It is not clear whether echinacea interacts with some medicines broken down by the liver, and it might interact with medicines that suppress the immune system.
Talk to a healthcare professional if: you want to give echinacea to a child, you are pregnant or breastfeeding, or you take any prescription medicine, especially one that suppresses the immune system.
Many trials have tested echinacea, and pooled results point to a small drop in the chance of catching a cold, far from prevention. Confidence is Limited because the products tested differed widely, no single prevention trial in the main review showed a clear effect on its own, and the largest positive analysis was partly paid for by an echinacea maker.
Echinacea does not reliably keep colds away; in pooled trials, people taking it were only slightly less likely to catch one. A 2014 Cochrane review of 24 trials with 4,631 people found that none of 12 prevention comparisons showed a clear effect on its own. Pooling them pointed to about 10% to 20% fewer people catching a cold, a benefit the reviewers called of questionable importance. A 2019 review found about 22% lower risk.
Products sold as echinacea are not all the same: they use different species, different parts of the plant and different ways of making the extract. A 2024 review partly funded by an echinacea maker reported a bigger effect, about 25% fewer people with at least one respiratory infection. Echinacea has also not been shown to shorten colds: only 1 of 7 treatment trials in the Cochrane review that reported cold length found a clear effect, and the 2019 review found a difference of about half a day that could be due to chance. The US National Center for Complementary and Integrative Health sums it up this way: echinacea may slightly reduce your chances of catching a cold.
- Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews. 2014;(2):CD000530. DOI: 10.1002/14651858.CD000530.pub3. PMID: 24554461
- David S, Cunningham R. Echinacea for the prevention and treatment of upper respiratory tract infections: a systematic review and meta-analysis. Complementary Therapies in Medicine. 2019;44:18-26. DOI: 10.1016/j.ctim.2019.03.011. PMID: 31126553
- Gancitano G, Mucci N, Stange R, et al. Echinacea reduces antibiotics by preventing respiratory infections: a meta-analysis (ERA-PRIMA). Antibiotics (Basel). 2024;13(4):364. DOI: 10.3390/antibiotics13040364. PMID: 38667040. PMCID: PMC11047471
- National Center for Complementary and Integrative Health. Echinacea: Usefulness and Safety. Last updated November 2024