How to pick an echinacea product that was tested, since most never were

Key takeaways

• A 2014 Cochrane review of 24 trials found that echinacea might lower the chance of catching a cold by roughly 10% to 20%, with little sign that it shortens a cold you already have¹.
• In a four-month trial, 755 adults took alcohol-based drops of fresh purple coneflower or a placebo; the echinacea group logged 149 colds versus 188, a gap the authors couldn’t call statistically significant, and the maker helped pay for the study³⁴.
• A 2003 check of 59 store products found that 6 held no measurable echinacea and only about half matched the species on the label¹².
• European products typically cap use at 10 days, and one official Irish label warns of low white blood cell counts with use beyond eight weeks¹⁰¹¹.
• Skip echinacea or ask a clinician first if you have a daisy-family allergy or an autoimmune disease, take immune-suppressing drugs, are pregnant or are buying for a child under 12⁸¹¹.

In the fall of 2009, 755 healthy adults signed up for a winter-long experiment at Cardiff University’s Common Cold Centre in Wales. Three times a day, each volunteer stirred 25 drops of an echinacea extract or a look-alike placebo into water, kept it on the tongue for a 10-second count and swallowed³⁴.

By April, the echinacea group had logged 149 colds. The placebo group had logged 188³.

That’s a modest gap, and the researchers said it fell short of statistical significance. Sick days told a clearer story, as you’ll see below. The result came from one specific product, Echinaforce: fresh purple coneflower, mostly the above-ground plant with a little root, extracted in alcohol³. Its maker, A.Vogel, helped fund the study⁴.

Now picture the supplement aisle. It holds root and herb capsules, tablets, liquid extracts and blends with other ingredients⁹. In 2014, a news release on the Cochrane review noted that the vast majority of echinacea products had never been tested in a clinical trial².

Our article “Echinacea came from the prairie and barely touched colds in big trials” covers the plant’s history and the large U.S. trials. This guide is for readers who still want to use it, and want to use it the way it was tested.

Pooled trials point to a small drop in colds, not a cure

Start with a 2014 Cochrane review. Its authors gathered 24 double-blind trials with 4,631 people, each comparing a single echinacea product with a placebo¹.

For prevention, none of the 12 comparisons that counted who caught a cold reached statistical significance on its own. Yet nearly all leaned the same way. When the reviewers pooled them after the fact, echinacea users were roughly 10% to 20% less likely to catch a cold¹.

What does that mean for you? Picture 100 adults, 40 of whom would catch a cold over a few months without echinacea (a round number we chose for illustration). A 10% to 20% drop would spare 4 to 8 of them, by our math, and 32 to 36 would still get sick.

Treatment looked weaker. Of six trials that reported how long colds lasted, only two found a benefit¹.

Later reviews tell a similar story with different math:

• 2019: Sholto David and Rebecca Cunningham pooled 16 trials. Echinacea lowered the chance of getting at least one respiratory infection by 12% to 22%, with no effect on how long illness lasted⁶.
• 2024: The ERA-PRIMA analysis pooled 30 trials with 5,652 people. People taking echinacea were 25% less likely to get a respiratory infection and 40% less likely to need antibiotics⁵. That project was paid for in part by A.Vogel, and three authors had received consulting fees from the company⁵.

The federal National Center for Complementary and Integrative Health (NCCIH), in its 2024 fact sheet, says echinacea might modestly cut the odds of catching a cold, while its effect on cold length remains unclear⁸. The Merck Manual’s 2025 review calls the results inconsistent and blames, above all, how much the preparations differ, from species to plant part⁷.

The four-month trial that anchors the prevention case

The Cardiff study, published in 2012, enrolled healthy adults who usually caught at least two colds a year. Here is what it found³:

• Colds: 149 on echinacea and 188 on placebo. The authors said the trial wasn’t big enough to show this gap was statistically significant.
• Days sick: 672 on echinacea and 850 on placebo, a statistically significant gap. The paper calls it a 26% difference, which is how much higher the placebo count was. Measured from the placebo side, echinacea users had about 21% fewer sick days, by our math.
• Repeat colds: 28 people on echinacea had more than one infection, compared with 43 on placebo.
• Health complaints: 293 reported adverse events on echinacea and 306 on placebo. About 9% and 10% of people had problems possibly linked to the drops.

In absolute terms, the echinacea group had 39 fewer colds over four months. If the groups were about equal in size, that’s roughly one cold avoided for every 10 people who took drops all winter, by our math.

The researchers also reported bigger benefits in people who took every dose³. Results from a subgroup are less reliable than the main comparison.

Three choices decide what’s in the bottle

Every echinacea product reflects three decisions, and each one changes the chemistry.

Species. Three species are in common use: Echinacea purpurea, E. angustifolia and E. pallida⁹.

Plant part. Products use the root, the aerial parts (stems, leaves and flowers) or both⁹.

Preparation. This is where products split most sharply:

• Pressed juice of fresh E. purpurea tops. Most EU countries license it in the “well-established use” category, while the Netherlands and the U.K. class it as a traditional herbal medicine¹⁰.
• Alcohol extracts of the fresh plant. The Cardiff product used 95% above-ground herb and 5% root, extracted in alcohol³.
• Dried root extracts in capsules. One echinacea root capsule registered in Ireland holds 140 mg of extract and is licensed only on the basis of long traditional use, not trial proof¹¹.

These forms don’t behave alike. In lab tests reviewed by the European Medicines Agency (EMA), an echinacea tincture blocked a key drug-processing liver enzyme, CYP3A4, more than 50 times as strongly as the pressed juice did¹⁰. The report tied the gap to alkamides, oily compounds in the plant. Whether it matters in people is unclear¹⁰.

The 2024 industry-supported review reported stronger results for alcohol-based and similar extracts than for pressed juices⁵. Keep its funding in mind, but the pattern makes one point clear: a trial of one form says little about another.

Then there’s the question of whether the bottle holds what it says. In August 2000, University of Colorado researchers bought 59 single-herb echinacea products in the Denver area¹².

Six held no measurable echinacea. In just 31, the species the lab found agreed with the label. Twenty-one bottles claimed to be “standardized,” yet fewer than half of those, 9, lived up to the standard printed on them¹².

That snapshot is old. For newer estimates of swapped herbs, see “Some herbal pills hide prescription drugs, and others swap out the herb.” For how quality seals work, see “Supplement Seals Test Different Things. Know Which One You’re Trusting.”

How trial volunteers took it, and for how long

If you choose echinacea, match the way you use it to the way it was tested.

For prevention, the Cardiff volunteers took 2,400 mg of extract a day, split into three doses of 25 drops³⁴. At the first sign of a cold, they raised the dose to 4,000 mg a day³.

For a cold that’s starting, European products are built around early, short use. Pressed-juice labels call for 6 to 9 ml a day, split into as many as four doses, and in most EU countries they limit nonstop use to 10 days, sometimes 14¹⁰. The Irish root capsule says one capsule twice a day from the first sign of a cold, for no more than 10 days¹¹.

For long use, the rules and the research pull apart. The Cardiff volunteers took drops for four months, and complaints matched placebo³. Labels disagree, too: Austria’s allow up to eight weeks without a break¹⁰. But the Irish product leaflet lists leukopenia, a drop in white blood cells, with use longer than eight weeks¹¹. Memorial Sloan Kettering’s herb database also describes a woman whose white count fell after long-term use and recovered months after she stopped⁹.

Season-long use goes beyond what most European labels allow. If you’re thinking about it, make that decision with a clinician.

Herbal traditions treat a plant as medicine, which means dose, timing and preparation matter. Using echinacea the way it was studied, for a set purpose and a set time, respects that view more than an open-ended daily habit does.

What the evidence supports, use by use

Use	What was tested	What was found	Rating
Lowering the odds of catching a cold	Many single-herb products, pooled16	About 10% to 22% fewer colds; individual trials mostly not significant	Promising but early
Fewer colds over a whole winter	Fresh-plant alcohol extract, 2,400 mg a day for four months3	149 vs. 188 colds (not significant); about 21% fewer sick days; maker co-funded	Promising but early
Shortening a cold with the products tested so far	Treatment trials of various products; 2019 pooled analysis16	Only 2 of 6 trials showed shorter colds; pooled data showed no effect on length	Evidence says no, or unsafe
Fewer antibiotics and complications	Pooled trials of several products5	40% fewer people needed antibiotics; industry-supported analysis	Promising but early
Preventing colds in children	One product in about 200 children57	Fewer infections and antibiotic prescriptions reported	Not enough evidence
Daily use beyond eight weeks	Four-month trial; label warnings311	Side effects like placebo in one trial; low white counts reported	Not enough evidence

Allergies, immune drugs and other reasons to pass

For most healthy adults, a short course of an E. purpurea extract looks low-risk, according to NCCIH, and the usual complaints are stomach upset and nausea⁸. The picture changes for the groups below.

• Daisy-family allergies. Echinacea shares a plant family with ragweed, daisies and sunflowers, and NCCIH warns that allergic reactions to it can be severe⁸. The Irish label rules it out for anyone allergic to the daisy family and warns that people prone to allergies risk anaphylaxis¹¹. See “Allergic to Ragweed? Chamomile, Echinacea and Feverfew Belong to Its Family.”
• Autoimmune disease and immune conditions. The Irish label rules out echinacea in autoimmune diseases such as multiple sclerosis, in HIV and tuberculosis, after organ or bone marrow transplants, during chemotherapy and in white blood cell disorders such as leukemia¹¹. The Merck Manual gives similar advice⁷. A later article in this series covers supplement cautions for autoimmune conditions.
• Immune-suppressing drugs. Echinacea may make transplant drugs such as tacrolimus and cyclosporine less effective, Memorial Sloan Kettering says⁹. The Irish label says not to combine them¹¹.
• Other medicines. NCCIH calls the evidence on liver-processed drugs conflicting⁸. Memorial Sloan Kettering reports that echinacea slows CYP3A4, though how much that matters in people is unknown, and describes a case of a severe drop in blood platelets with the cancer drug etoposide⁹. It urges caution during chemotherapy, so ask your oncologist first⁹. Bring the bottle to your pharmacist.
• Children. Several European labels advise against echinacea under age 12¹⁰¹¹. Ask the child’s clinician first; our prairie history article covers the rashes seen in a large children’s trial.
• Pregnancy and breastfeeding. Advice splits here. The Irish label says not to use it during either¹¹, while NCCIH considers a course of up to a week early in pregnancy possibly safe and says too little is known about nursing⁸. See “A few herbs are known pregnancy risks, and most were never tested.”
• Rare liver injury. Memorial Sloan Kettering lists case reports of hepatitis, including acute liver failure likely caused by echinacea in a 2-year-old girl⁹.
• Surgery. Tell your surgical team you take it. “Told to Stop Fish Oil Before Surgery? A Big Trial Found No Extra Bleeding” covers stop times.

The echinacea product checklist

Use this at the shelf or before you click “buy.” It’s built around one question: does this bottle match something that was tested?

Question to ask	What to look for	Why it matters
Is my goal prevention or treatment?	Daily use through cold season, or a short course at first symptoms	Prevention has a small pooled benefit; treatment has little1
Was this product, or this exact preparation, studied?	A named published trial of the product, or a form matching Europe’s pressed juice310	Most products have never been tested2
Which species and part?	A Latin name and “herb,” “aerial parts” or “root”	Differences in species and parts help explain conflicting results79
Juice, alcohol extract or dried powder?	“Fresh plant,” “pressed juice,” “tincture” or “dry extract”	Tinctures blocked a drug enzyme far more than juice in lab tests10
Is the daily amount close to the studied one?	Milligrams of extract per day, such as 2,400 mg for prevention3	A much smaller dose isn’t what was tested
Is it a blend?	Zinc, elderberry, goldenseal or other herbs	Trials in the 2014 review tested single-herb products1
Can I verify what’s inside?	A seal you can look up on the program’s own site	Some store products held no echinacea at all12
Is it safe for me?	No daisy allergy, autoimmune disease, immune drugs, pregnancy or child under 12	The Irish label rules these out or advises against use11
When will I stop?	A stop date written down	Most labels cap nonstop use at 10 to 14 days; long use has prompted warnings1011

Signs to stop, and when to get help

Stop echinacea and get medical advice if a rash, hives or swelling appears. The Irish label’s list of possible reactions runs from hives and skin swelling to asthma attacks, Stevens-Johnson syndrome (a severe skin reaction) and anaphylactic shock¹¹.

Anaphylaxis is a severe, whole-body allergic reaction. Its signs include a swollen face, eyes or tongue, wheezing, trouble breathing and a very hoarse or whispered voice, which can mean the throat is swelling. MedlinePlus, the National Library of Medicine’s health site, says to call 911 for severe symptoms¹⁴.

The cold itself may need care, too. The Centers for Disease Control and Prevention (CDC) advises seeing a health care professional for these¹³:

• Trouble breathing or fast breathing
• Signs of dehydration
• Fever lasting more than four days
• Symptoms lasting more than 10 days without improvement
• Symptoms that improve, then return or worsen
• A chronic condition that gets worse

For a baby younger than 3 months, CDC says to call a professional right away for a fever of 100.4°F or higher¹³.

Questions readers ask

The bottom line

The pooled research suggests echinacea may slightly lower your odds of catching a cold. It probably won’t shorten one. The strongest prevention data come from one fresh-plant alcohol extract, tested in a trial its maker helped fund, and most products on the shelf have never been tested at all.

If you want to use it, pick a product whose species, part and preparation match a studied one. Take it the way volunteers did, set a stop date and skip it if you have a daisy-family allergy, autoimmune disease, immune-suppressing medicines, a pregnancy or a child under 12.

Keep exploring: elderberry immune support.

Related reading

• Echinacea came from the prairie and barely touched colds in big trials
• If you’re allergic to ragweed, chamomile, echinacea and feverfew belong to its family
• An Herbal Extract Isn’t Just a Stronger Herb. It’s a New Product
• Supplement Seals Test Different Things. Know Which One You’re Trusting
• Elderberry is sold for all-winter immunity, but its main flu trials lasted days

Sources

1. 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, Issue 2, CD000530 (abstract and plain-language summary). cochranelibrary.com and cochrane.org
2. Health Behavior News Service. “Evidence Mixed on the Usefulness of Echinacea for Colds.” Newswise, February 20, 2014. newswise.com
3. Jawad M, Schoop R, Suter A, Klein P, Eccles R. “Safety and Efficacy Profile of Echinacea purpurea to Prevent Common Cold Episodes: A Randomized, Double-Blind, Placebo-Controlled Trial.” Evidence-Based Complementary and Alternative Medicine, 2012, article 841315 (journal page; Cardiff University repository record). dx.doi.org and orca.cardiff.ac.uk
4. NutraIngredients (trade press). “Echinacea Extract May Help Prevent Common Cold: Study” (reports the trial was partly funded by A.Vogel). October 25, 2012. nutraingredients.com
5. Gancitano G, et al. “Echinacea Reduces Antibiotics by Preventing Respiratory Infections: A Meta-Analysis (ERA-PRIMA).” Antibiotics, 2024;13:364 (supported in part by A.Vogel AG). University of Westminster repository. pubmed.ncbi.nlm.nih.gov
6. McMaster Optimal Aging Portal. Summary of 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. Accessed October 2026. mcmasteroptimalaging.org
7. Shane-McWhorter L. “Echinacea.” Merck Manual Professional Edition, reviewed July 2025. merckmanuals.com
8. National Center for Complementary and Integrative Health. “Echinacea.” NIH, last updated November 2024. nccih.nih.gov
9. Memorial Sloan Kettering Cancer Center. “Echinacea.” About Herbs, updated August 7, 2023. mskcc.org
10. European Medicines Agency, Committee on Herbal Medicinal Products. “Assessment Report on Echinacea purpurea (L.) Moench, Herba Recens.” Final, November 24, 2014. ema.europa.eu
11. Health Products Regulatory Authority (Ireland). Summary of product characteristics for a registered traditional herbal medicine containing Echinacea purpurea root dry extract (TR23157/008/001), text revised February 2021. assets.hpra.ie
12. Gilroy CM, Steiner JF, Byers T, Shapiro H, Georgian W. “Echinacea and Truth in Labeling.” Archives of Internal Medicine, 2003;163(6):699-704 (abstract reproduced by Chiro.org), with HealthDay coverage, March 24, 2003. chiro.org and healthday.com
13. Centers for Disease Control and Prevention. “Preventing and Managing the Common Cold.” CDC fact sheet, 2026. cdc.gov
14. MedlinePlus Medical Encyclopedia. “Anaphylaxis.” National Library of Medicine, reviewed January 20, 2026. medlineplus.gov