Echinacea

What is echinacea, and which species are used in supplements?

Echinacea is a plant genus native to North America; the three species most often used in supplements and herbal products are E. angustifolia, E. pallida, and E. purpurea. ^[8] The Cochrane review emphasizes that the composition of products sold under the name Echinacea differs markedly, mainly because of variable plant material, different extraction methods, and the addition of other components. ^[2] The studies included in the same review were conducted with different species and plant parts; only seven studies had evidence on products prepared from the aerial parts of E. purpurea. ^[2]

For this reason, a result found for “echinacea” in one study cannot be carried directly over to another product bearing the same name. NCCIH also mentions new research suggesting that the activity of echinacea extracts is affected by soil conditions that influence the plant’s bacterial community. ^[1]

Does echinacea have a function in the body, and who uses it?

Echinacea is not a nutrient; it has no defined required function or deficiency in the body. The purpose of use is the prevention and treatment of the common cold and upper respiratory tract infections; the Cochrane review notes that it is widely used for this purpose in Europe and North America. ^[2] NCCIH also reports that it is unclear whether it works for eczema. ^[1] In the sections below, these claims are separated by study type.

Does echinacea protect against the common cold?

The Cochrane review (Karsch-Völk et al., search June 2013) included double-blind RCTs comparing single echinacea products with placebo: 24 studies, 4,631 participants, 33 comparisons. Of these, 10 (13 comparisons) examined prevention and 15 (20 comparisons) examined treatment; one study examined both. Because clinical diversity among studies was too great, the authors did not pool the data in the main analysis. None of the 12 prevention comparisons reporting the number of people with at least one cold showed a statistically significant difference; however, a later (post hoc) pooling of them suggested a 10–20% relative risk reduction. The authors state that individual prevention studies showed consistently positive (but nonsignificant) trends, but that the clinical importance of the possible effect is debatable. ^[2]

The 2019 meta-analysis by David and Cunningham included any echinacea-containing product in double-blind placebo-controlled RCTs. A risk ratio of 0.78 (95% CI 0.68–0.88) was found for prevention of upper respiratory tract infection. The authors state that whether this is clinically meaningful is debatable and that the results are limited by risk of selective reporting and methodological heterogeneity. ^[3] NCCIH also says that echinacea may “slightly” reduce the chance of catching a cold. ^[1] The two reviews point in the same direction; the difference is that no pooling was done in the first, whereas the second analyzed all echinacea products together.

Does echinacea shorten the common cold?

Of the seven treatment studies reporting duration in the Cochrane review, only one showed a significant effect of echinacea over placebo; the authors’ conclusion is that echinacea products were not shown in this review to benefit treatment of the common cold. ^[2] In the meta-analysis by David and Cunningham, the mean difference in illness duration was −0.45 days; the authors reported finding no evidence of an effect on duration. ^[3]

The RCT by Barrett and colleagues in Wisconsin divided 719 people aged 12–80 with a newly started cold into four groups: no pill, placebo (blinded), echinacea (blinded), and echinacea (open-label). When the blinded groups were compared, there was a trend of 28 points in illness severity (95% CI −69 to 13; p = 0.089); the difference in illness duration was 0.53 days (CI −1.25 to 0.19 days; p = 0.075), both nonsignificant; changes in interleukin-8 and neutrophils were also not significant. The authors noted that high variability limited the power to detect small benefits; the main funding was from NIH (NCCAM). ^[4]

In the NEJM study by Turner and colleagues, 437 volunteers were experimentally infected with rhinovirus type 39; extracts made from E. angustifolia root by three different methods (supercritical carbon dioxide, 60% ethanol, 20% ethanol) showed no significant effect on infection rate or symptom severity (399 volunteers in the analysis). ^[5] This is a laboratory-like controlled virus-challenge model; it does not map one-to-one onto results in naturally acquired colds.

What is the place of echinacea in children?

The JAMA study by Taylor and colleagues compared E. purpurea with placebo in healthy children aged 2–11: 707 upper respiratory tract infections in 407 children were analyzed. The median duration was 9 days, and there was no difference between echinacea and placebo in duration (p = 0.89) or severity (p = 0.69). The overall adverse event rate was similar; however, rash was seen in 7.1% of infections treated with echinacea and 2.7% of those treated with placebo (p = 0.008). ^[6]

The study by Ogal and colleagues examined prevention in children aged 4–12; the control was vitamin C, not placebo (103 children in the echinacea arm, 98 in the vitamin C arm). 429 illness days were reported in the echinacea arm and 602 in the control arm; echinacea gave an OR of 0.52 (95% CI 0.30–0.91) for a respiratory tract infection episode. An antibiotic course was recorded in 6 children (5.8%) in the echinacea arm and 15 children (15.3%) in the control arm. The study was funded by the product’s manufacturer, and one of the authors is a manufacturer employee and another is a manufacturer consultant; the authors state that data evaluation was done at an independent provider. ^[7] Because it is a single RCT with manufacturer support, the result cannot be accepted as definitive. NCCIH also mentions a recent study showing a reduced risk of infection and complications in children, but states that this is not enough for a clear link. ^[1]

Is echinacea safe, and who should be cautious?

The systematic review by Huntley and colleagues (2005; combination and homeopathic products excluded) concluded from clinical studies and spontaneous reporting programs that adverse events attributable to echinacea are not commonly reported; the most common are digestive disturbances and rashes, and severe allergic reactions can occur rarely. The authors state that short-term use has a relatively good safety profile, but that people with allergy or asthma should weigh use carefully and that, because of a lack of data, use in pregnancy and breastfeeding would not be wise. ^[8]

NCCIH reports the following: E. purpurea extracts and some E. purpurea–E. angustifolia mixtures are possibly safe for most adults in the short term; the most common side effects are digestive symptoms such as abdominal pain and nausea. Short-term E. purpurea extract in children is reported to be “possibly safe,” but in one clinical study some children developed a rash that may have been allergic. For drug interactions, there is conflicting evidence regarding some drugs metabolized in the liver; interaction with immunosuppressive drugs or caffeine is considered theoretically. In pregnancy, some studies with solid or liquid extracts of E. purpurea and E. angustifolia suggest that use for up to 7 days in the first trimester is possibly safe; safety in breastfeeding is unknown. ^[1] The assessment by Huntley and colleagues that use in pregnancy is not wise stands next to NCCIH’s first-trimester information; the two sources do not reach the same conclusion.

In the Cochrane review, the number of people who dropped out because of adverse effects or reported adverse effects did not differ significantly between echinacea and placebo in any of the prevention and treatment studies; in the prevention studies, however, there was a trend toward a higher number of dropouts due to adverse events in the echinacea arms. ^[2] In the safety meta-analysis by David and Cunningham, the risk ratio was 1.09 (95% CI 0.95–1.25); the authors state that no marked risk is seen in the short term, but that the results are limited by selective reporting and methodological heterogeneity. ^[3]

The overall picture is therefore as follows: in short-term use, no serious safety problem stands out in studies, but allergic reaction and the scarcity of pregnancy/breastfeeding data remain limitations.

What is the status of echinacea in Türkiye?

In the Plant List of the Ministry of Agriculture and Forestry (updated July 16, 2026), three echinacea plants are on the positive (P) list: E. angustifolia (aerial parts), E. purpurea (aerial parts, rhizome, root), and E. pallida (root). For each row, the label of products containing this plant is required to carry the warning “12 yaş altı çocuklar tarafından kullanılmamalıdır. Bağışıklığı baskılayıcı ilaçlarla birlikte kullanılmamalıdır.” (not to be used by children under 12; not to be used together with immunosuppressive drugs); food business operators must comply with this regulation by November 18, 2025, and foods placed on the market before November 18, 2025 may remain on the market until November 18, 2027. ^[9]

In the September 21, 2026 version of the Restricted Substances List for Dietary Supplements, echinacea appears in two rows. In the “Echinacoside” row (E. angustifolia, E. purpurea, E. pallida), 21 mg/day is written in the age 11 and over maximum column (published June 27, 2016); the 4–10 year columns are blank. In the “Polyphenols” row, grape, E. purpurea, tea, elderberry, aronia, pomegranate, and cat’s claw are listed together as sources; 270 mg/day is written for ages 4–10 and 540 mg/day for ages 11 and over (age 11 and over published May 2, 2016, ages 4–10 June 16, 2017). ^[10] These limits are for the marker compound (echinacoside) and total polyphenol amount; they are not in the same unit as the extract or root weight used in studies. Dietary supplements are also covered on the page supplement regulation in Türkiye. This guide does not recommend products or places of supply and does not set personal doses.

Evidence table: claim, population, and limits