Echinacea, Elderberry, Pelargonium: Which Herbal Cold Remedies Hold Up in Studies

It is November. It has been drizzling for days, and half the office is sniffling. Then one evening your throat starts to scratch.

Herbal cold remedies are popular, and I understand why. They feel gentle, familiar and a little like taking matters into your own hands. The only question is: which of them stand up to an honest test?

The starting point is sobering. A 2024 Cochrane review states that there is so far no established measure that prevents colds or shortens their duration. So every remedy starts from zero and has to prove itself.

What happens in your body during a cold?

Your nose is running, your head feels heavy, and all you want is to crawl under the covers. It feels as if a virus has taken over. May I offer you a different view?

Colds are triggered by many different viruses. According to a 2003 review from Turku in Finland, rhinoviruses play the biggest role. In about a quarter of all colds, the pathogen remained unknown at the time.

This matters for everything that follows. A cold remedy would have to work against many different pathogens, not against a single one.

On top of that, a large part of your symptoms does not come directly from the virus, but from your own defences. A team at the University of British Columbia in Vancouver showed this in the laboratory using human bronchial cells. Cold viruses caused the cells to release messenger substances such as interleukin-6 and interleukin-8.

Imagine these messengers as smoke alarms. They call in immune cells, make the mucous membranes swell and get the mucus flowing. Loud, unpleasant, but part of the defence.

From the perspective of clinical psychoneuroimmunology, KPNI for short, a cold is therefore a whole-body event. Nervous system, hormones, metabolism and immune system negotiate with each other about how much strength flows into your defences.

Anthroposophic medicine also describes an infection as a process the organism goes through, not just as a disturbance. That is a view from tradition, not a study result. I still find it valuable, because it shifts the focus from the symptom to the whole person.

And now you know why I ask the same question about every cold remedy: does it change the course of the illness, or does it just feel like doing something?

Cold or flu: where is the line?

Sometimes it is not a scratch, but a blow. At lunchtime you were still fine, by evening you have a high fever and every muscle aches. That feels different from a sniffle. Usually, it is.

Only a test can reliably tell the two apart. The difference still matters, because there are antiviral medicines against flu. The guideline of the Infectious Diseases Society of America, IDSA, recommends starting them as early as possible in people at increased risk.

According to the guideline, these risk groups include people aged 65 and over, children under two and pregnant women, among others. Added to these are people with chronic diseases of the heart, lungs, kidneys, liver or metabolism, and people with a weakened immune system. In otherwise healthy adults, treatment can be considered if symptoms have lasted no more than two days.

This is exactly where this article draws its line. The plants we are about to look at are not an alternative in real flu. A careful study of elderberry extract in confirmed flu found no benefit. More on that shortly.

Whether an annual flu vaccination makes sense for you is something you can discuss with your GP in the autumn. That is the subject of a separate conversation, not of this article.

And now you know why the first question in November is not which syrup, but which infection.

What can echinacea do for a cold?

For many people, echinacea is the ultimate cold remedy. Maybe the drops already stood in your parents' bathroom cabinet. But if you read the studies, you quickly become unsure. Some are enthusiastic, others wave it away. How can that be?

A family name, not an active ingredient

Three species go by the name echinacea: purple coneflower, narrow-leaved coneflower and pale purple coneflower. The herb, the root or both are used. Sometimes freshly pressed, sometimes as an alcoholic extract, sometimes dried in tablets.

A juice pressed from the fresh herb and a tablet made from dried root are as different as apple juice and ground apple seeds. Both carry the same name. In your body, they can behave entirely differently.

What the large analyses show

Other analyses sound friendlier. A 2007 meta-analysis from the University of Connecticut calculated from 14 studies 58 percent lower odds of catching a cold and a duration shortened by 1.4 days. The Cochrane authors later explicitly refrained from such an overall calculation across very different preparations.

A four-month study from the Common Cold Centre at Cardiff University with 755 healthy adults points in the same direction. It tested an alcoholic extract of fresh purple coneflower, mostly herb with a little root. The echinacea group had fewer colds, fewer cold days and fewer episodes in which painkillers were used. Adverse events occurred about as often as with placebo.

And in the laboratory? The Vancouver team showed that an alcoholic extract of herb and root dampened the release of alarm signals in bronchial cells for all the viruses tested. It also inactivated enveloped viruses. Rhinoviruses, the most common cold viruses, do not have such an envelope, however.

When you should avoid echinacea

Echinacea belongs to the daisy family, like chamomile, arnica or calendula. If you are allergic to this plant family, the EU monograph lists echinacea as unsuitable. People prone to allergies should seek medical advice beforehand, because severe hypersensitivity reactions are possible.

An analysis from Australia shows how serious this can be. Two Australian doctors evaluated 51 reports to the national adverse drug reactions committee. Of these, 26 were consistent with an immediate allergic reaction, including 4 cases of anaphylaxis and 12 acute asthma attacks. Striking: 20 out of 100 people prone to allergies reacted to echinacea in a skin test, even though they had never taken it.

In autoimmune diseases such as Hashimoto's, multiple sclerosis or rheumatoid arthritis, the EU monograph advises against echinacea. The same applies to immune deficiency, to immunosuppression such as after an organ transplant, to progressive systemic diseases and to diseases of the white blood cells. The concern behind this: a remedy that influences the immune system might give a misdirected immune response an additional push.

This has not been proven. A pharmaceutical team at the University of Graz even considers these restrictions questionable, because some fat-soluble preparations tend to dampen cellular immune responses. The monograph nevertheless remains cautious: a link with autoimmune diseases cannot be ruled out. I stick to the more cautious line. With Hashimoto's or another autoimmune disease, there are levers that raise fewer questions.

On duration: the monograph limits use to a maximum of ten days, for prevention as well as treatment, and advises starting at the first signs. Prevention studies, by contrast, sometimes ran for months, and the Graz team saw no toxicological concerns in long-term studies of up to six months. During pregnancy and breastfeeding, the monograph advises against it, unless on medical advice.

And now you know why two people can have entirely different experiences with “echinacea”.

What can elderberry do for a cold?

There is something homely about elder. The shrub by the garden fence, the white flower clusters in early summer, the black berries in late summer. Many people remember hot elderberry juice from childhood. How much of this does research support?

Flower and berry: two remedies on the same shrub

With elder, two quite different plant parts are used. The flowers end up in your cup as tea. The berries as juice, syrup or extract in capsules and lozenges.

For elderflowers, the European Medicines Agency, EMA, maintains a monograph as a traditional herbal medicinal product. According to it, they can be used to relieve early cold symptoms. This classification is based on long-standing use, not on clinical studies.

For the berries, by contrast, the responsible committee did not adopt a monograph after its review. The assessment ended in 2014 with a public statement. Yet most of the studies you find in product descriptions concern precisely extracts from the berries.

In 2019, a meta-analysis from the Franklin Institute of Wellness in Tennessee pooled randomised studies on colds and flu with a total of only 180 participants. It reports a marked reduction in respiratory symptoms. With so few people, however, even single studies can shift the overall picture considerably.

In the laboratory, things look friendlier. In cell cultures at Justus Liebig University Giessen, a standardised elderberry extract inhibited the replication of flu viruses and the growth of some respiratory bacteria. So an effect is biologically plausible. The Cleveland study shows how big the step from test tube to human being can be.

Raw, unripe, stalks: where elder gets tricky

Elderberries are not a harmless snack fruit. Unripe berries contain sambunigrin, a substance from which hydrogen cyanide can form. The content drops as the berries ripen, as a team at the University of Innsbruck describes. In an analysis from the University of Ljubljana, leaves and flowers contained more of these substances than the berries.

That is why an old rule applies in the kitchen: only ripe berries, without stalks, and traditionally only cooked, never raw. For elderflower tea, the monograph advises against use in children under twelve and during pregnancy and breastfeeding, because data are lacking. If shortness of breath, fever or pus-like phlegm develop, the infection should be checked by a doctor.

And now you know why, with elder, one question comes first: flower or berry?

What does the evidence show for South African geranium?

Many people know South African geranium only as drops at the first sign of a cough. The plant comes from southern Africa, and it is the root that is used. That sounds exotic and thoroughly researched at the same time. Are both true?

In Germany, an extract from the root is licensed as a medicine for acute bronchitis. At EU level, the EMA lists the root as a traditional herbal medicinal product for relieving cold symptoms. Most of the studies I cite here use the same special extract.

A cold study at the National Medical University in Kyiv included 103 adults whose symptoms had been present for 24 to 48 hours. After ten days, 78.8 percent of the pelargonium group were considered clinically recovered, compared with 31.4 percent with placebo. Those treated were unable to work for 6.9 days on average, the placebo group for 8.2 days.

The liver warning: what is behind it

Now to the tricky part. In 2011, Germany's Federal Institute for Drugs and Medical Devices, BfArM, opened a formal drug safety procedure on medicines containing pelargonium. According to the German medical journal Deutsches Ärzteblatt, there were 30 suspected cases of liver damage by mid-2012, including one person who needed a liver transplant. In 2014, the authority ordered a warning about possible liver damage in the package leaflets.

The current 2024 EU monograph also states: cases of liver damage and liver inflammation have been reported, and their frequency is unknown. If there are signs of liver damage, the product should be stopped immediately and medical advice sought.

Whether the plant was actually the cause is disputed. A team led by Teschke at Hanau Hospital in Germany examined 15 reported cases using a liver-specific causality assessment method. In none of the cases was causality rated highly probable or probable, and findings to rule out other causes were often missing.

If you have a known liver disease, drink alcohol regularly or take several medicines that are broken down by the liver, I would only take pelargonium after talking to a doctor. The monograph also lists nosebleeds and bleeding gums as possible side effects. If you take blood thinners, I would therefore discuss it beforehand.

According to the monograph, liquid preparations are intended from the age of three, and use below that age is not recommended. During pregnancy and breastfeeding, it advises against use because data are lacking. If symptoms last longer than a week, the infection should be checked by a doctor.

Why the liver plays a role with many plants is something you can read in my article on milk thistle and the liver.

And now you know why, with pelargonium, I ask about your liver first and only then about your cough.

How do the three plants compare head to head?

You are standing in front of the shelf again. This time with more knowledge, but perhaps also with more questions. Here is everything at a glance.

What I often see in my practice: many people take three or four products at the same time. Afterwards, nobody knows what helped and what was a side effect. I prefer one deliberately chosen remedy, for a limited time, to a cocktail.

And now you know why a comparison matters more than a test winner.

What role do sleep, stress, vitamin D and zinc play?

Honestly: how much did you sleep in the week before it caught you? Many colds do not announce themselves in your throat, but in your calendar.

This is where the KPNI lenses meet. Your nervous system evaluates strain, your hormonal system responds with stress hormones, and your immune system gets less room to manoeuvre. Sleep is the time when many of these systems might reorganise themselves.

How morning light might support your sleep rhythm in the dark half of the year is something you can read in Morning light and your internal clock. Gentle herbal companions for the night are covered in Valerian and passionflower.

Vitamin D: a small but measurable contribution

How sun, winter and vitamin D are connected is something you can read in Vitamin D deficiency in winter. How to take it sensibly is explained in Taking vitamin D the right way.

Zinc: more for the course than for prevention

A meta-analysis from the University of Helsinki found colds that were 33 percent shorter in seven studies with zinc lozenges. For doses above 100 milligrams a day, there was no indication of a greater benefit. Such amounts are intended for the duration of an infection, not as a long-term solution, and if you have existing conditions they should be discussed with your doctor.

How nature and rest might take the strain off your stress system is something you can read in Forest bathing for stress.

And now you know why, in autumn, I ask about your sleep first and then about your medicine cabinet.

What can you do now, in practical terms?

You do not have to avoid the shelf. But you can look at it with different eyes.

You may know a similar tension between tradition and studies from my article on black seed oil.

If you don't just want to read but want to get started right away: below this article you will find the option to book an appointment.

Frequently asked questions about herbal cold remedies

Read on in the ViveCura guide

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