Echinacea

Is echinacea safe?

For most adults taking it for a week or so at the first sign of a cold, yes. Stomach upset is the most common side effect, and NCCIH considers short courses of Echinacea purpurea extracts likely safe. The risk is concentrated in three groups: people with allergies, children, and people with autoimmune disease or on immunosuppressants. The other weak point is the product itself, which often does not contain the species or dose on the label.

Allergy is the main risk

Echinacea belongs to the daisy family, the same as ragweed, chrysanthemums and marigolds. The European Medicines Agency lists allergy to this family as a reason not to use it, and warns of a possible risk of severe reactions in atopic people, meaning those with hay fever, asthma or eczema.

Australian data show why. A 2002 review of 51 adverse reaction reports to the national regulator found 26 that looked like true allergic reactions: 4 anaphylaxis, 12 acute asthma attacks and 10 cases of hives or swelling. More than half of these patients were known to be atopic, four were admitted to hospital and four reacted on their first known dose. The same authors found that 20 of 100 atopic patients who had never taken echinacea already tested positive to it on skin prick, which points to cross-reactivity with other plant allergens.

The EMA monograph also records cases of Stevens-Johnson syndrome, a severe skin reaction, and bronchospasm, with unknown frequency.

Echinacea in children

The best trial in children is not encouraging. In a 2003 JAMA study, 407 children aged 2 to 11 were treated for 707 colds with E. purpurea or placebo. Echinacea did not shorten the colds or make them milder, and rash appeared during 7.1% of treated colds against 2.7% on placebo. A later analysis of the same trial suggested fewer repeat colds, a finding the authors said needed testing in a new trial.

The EMA does not recommend echinacea under 12 because safe use has not been documented well enough. NCCIH notes concern that allergic reactions in children could be severe.

Liver, autoimmune disease and drug interactions

LiverToxLiverToxA free US National Institutes of Health database that summarises what is known about liver injury caused by medicines, herbs and supplements.More in the glossary, the US government's liver injuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary database, describes echinacea as generally well tolerated but records isolated reports of raised liver enzymes and clinically apparent liver injury. Cases summarised by Memorial Sloan Kettering include severe acute hepatitis in a 45-year-old man taking high daily doses, and acute liver failure in a 2-year-old girl.

Because echinacea is meant to stimulate the immune system, the EMA advises against it in autoimmune diseases, immune deficiency, immunosuppression and white blood cell disorders. It says a link with autoimmune disease cannot be excluded.

On drugs, a 2004 study in 12 volunteers found that 400 mg of echinacea root four times a day for 8 days changed how the body handled midazolam and slowed the clearance of caffeine. The effect on most medicines is unknown. MSKCC lists possible weakening of the transplant drugs tacrolimus and cyclosporine, and a reported case of very low platelets in a patient on the chemotherapy drug etoposide.

What is actually in the bottle?

Three species are sold, from different plant parts, as dried herb, root powder, tincture or pressed juice. They differ chemically, so "echinacea" on a label says little.

FDA recall records add pesticide residues above legal limits in a bulk echinacea extract (2014) and an echinacea tea (2024), and Salmonella in raw material for a throat tea (2018).

How to use it more safely

1. Skip it if you are allergic to ragweed or daisies, or have had severe allergic reactions or asthma, unless your doctor agrees.
2. Keep courses short, about 7 to 10 days, as licensed products in Europe do.
3. Choose a product that names the species and plant part, ideally a licensed herbal medicine, since the 2024 review found these less often adulterated than supplements.
4. Talk to your doctor or pharmacist first if you have an autoimmune disease, take immunosuppressants or chemotherapy, are pregnant, or are buying it for a child.

For other cold remedies, see our pages on elderberry and zinc.

How we scored it

Regulatory actions (80) reflect a legal product that is licensed in Europe with clear warnings and no bans. Dose safety (75), organ toxicity (72) and interactions (72) are held back by allergy reports including anaphylaxis, isolated liver injuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary and enzyme effects. Product quality (48) is the weakest factor, with repeated tests finding the wrong species or no echinacea at all.