Remedy · herb & leaf
Echinacea for colds: what the evidence says
One of the most-tested herbs for colds. The trials point to, at best, a small drop in the chance of catching a cold and no clear effect on how long one lasts.
By the editors of Alimentotherapy Last reviewed 3 min read Not medical advice
Echinacea
Echinacea purpurea, E. angustifolia
Best-supported use: Lower chance of catching a cold
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The short answer
Echinacea has not been shown to shorten colds: in a Cochrane review of 24 double-blind trials, only one of seven treatment trials that measured duration found a significant effect Karsch 2014. For catching a cold in the first place, individual trials showed small, non-significant trends that pooled to a possible 10 to 20 percent relative reduction, an effect the reviewers called of questionable clinical relevanceKarsch 2014; NCCIH.
The evidence, use by use
Each claim graded on human studies only. How we grade
| Use | Grade | What the research found |
|---|---|---|
| Lower chance of catching a cold | Limited | None of 12 prevention comparisons was significant on its own; a post hoc pooling suggested a 10 to 20 percent relative risk reduction. NCCIH says echinacea may slightly reduce the chance of catching a cold. Karsch 2014; NCCIH |
| Shorter colds once you have one | Not supported | Of seven treatment trials reporting cold duration, only one showed a significant benefit over placebo. Karsch 2014 |
| Eczema and other skin uses | Not supported | It is unclear whether echinacea helps eczema or other conditions; there is little research. NCCIH |
Not one product but many
"Echinacea" on a label can mean different species (mostly E. purpurea, E. angustifolia and E. pallida), different parts of the plant (flowers and leaves, or roots), and different extraction methods. The Cochrane reviewers point out that most buyers and many doctors do not realize how much these products differ, and it is one reason the trials could not be pooled into a single answer Karsch 2014.
NCCIH also notes research suggesting that soil conditions, through the plant's bacterial community, change how active an echinacea extract is NCCIH. So a positive trial of one product says little about the bottle on a shop shelf.
If you want to try it
Short courses of E. purpurea extracts are likely safe for most adults NCCIH. If you want a single-species tea or extract, iHerb stocks several; look for the species and plant part named on the label, and expect a modest effect at most.
Safety
Echinacea is a close relative of sunflowers, daisies and ragweed. Allergic reactions happen and can be severe. Children in one trial developed rashes. Talk to your child's clinician before giving it NCCIH.
What has better support for colds
For a cough with a cold, honey has more trial support than echinacea (see the honey page). For everything else, fluids and rest remain the plain advice. See the colds page for each option graded side by side.
Before you try it: safety and interactions
Who should avoid it or ask first
- You are allergic to ragweed, daisies or sunflowers, which are close relatives of echinacea.
- You take an immunosuppressant, or drugs processed by the liver: interactions are conflicting or theoretical, so ask your prescriber.
- The person is a child: check with their clinician first.
Possible side effects
- Digestive symptoms such as abdominal pain and nausea.
- Allergic reactions, which may be severe, especially in people allergic to ragweed and related plants.
- Rashes in some children.
Pregnancy and breastfeeding
Some studies suggest certain extracts are possibly safe for up to 7 days in the first trimester, but consult your clinician. Little is known about breastfeeding. NCCIH; Karsch 2014
Medicine interactions
Check another food or medicine in the interactions list.
Common questions
Does echinacea shorten a cold?
It has not been shown to. In a 2014 Cochrane review, only one of seven treatment trials that measured cold duration found echinacea worked better than placebo. NCCIH says it is still unclear whether echinacea shortens colds.
Can echinacea stop you catching a cold?
At most it may slightly lower the chance. The Cochrane review found no single prevention comparison was significant, though pooling them suggested a 10 to 20 percent relative reduction, which the authors judged of questionable clinical relevance.
Sources
Primary research and government sources, each checked on the date this page was reviewed.
Keep reading
- GoalFood and colds: honey, zinc, vitamin C and chicken soupNo food stops a cold. Honey has good evidence for easing cough in children over one, and regular vitamin C slightly shortens colds; most other remedies are comfort.
- RemedyElderberryA popular syrup with a short, conflicting trial record. Early small studies suggested faster recovery from flu; the most carefully run recent trial found none. Raw berries are toxic until cooked.
- RemedyHoneyA spoonful of honey has decent trial support for children's coughs at night. It must never be given to a baby under 12 months because of infant botulism.
- ToolFood and drug interactionsCheck a remedy or food against common medicines.