Elderberry for Colds and Flu: What It Can (and Can’t) Do

Every cold and flu season, elderberry syrups, gummies and drops fly off the shelves. The deep purple berries of the black elder (Sambucus nigra) have been a folk remedy for coughs and fevers in Europe for generations, and today elderberry is one of the best-selling herbal supplements in the United States. The marketing usually promises that it will “boost your immune system”. The research tells a narrower, more useful story.

Here is what we found after reading the trials and the government fact sheets: elderberry may help you get over a cold or flu a little faster once you are sick. It has not been shown to stop you from catching one. And the most famous “natural cold remedy” of all, a spoonful of honey, has some of the best evidence on this list.

What elderberry actually is

Supplements are made from the cooked or extracted ripe berries of the black elder. The berries are rich in anthocyanins, the same purple pigments found in blueberries and blackcurrants. In the lab, elderberry extracts can stop some flu viruses from latching onto cells and can nudge immune signalling, which is why scientists got interested in the first place.

One important point before anything else: raw elderberries are not safe to eat. Raw or unripe berries, and the leaves, bark and stems, contain compounds that can cause nausea, vomiting and severe diarrhea. Commercial syrups, extracts and properly cooked berries are processed to avoid this. Do not make your own from berries you have picked unless you know exactly what you are doing.

🤧 Colds: it may shorten them

The largest trial we found was published in Nutrients in 2016. Researchers gave 312 economy-class passengers flying from Australia overseas either elderberry extract capsules or a placebo, starting ten days before the trip and continuing a few days after landing. Elderberry did not significantly reduce the number of people who caught a cold. But those in the elderberry group who did get sick had colds that were about two days shorter on average, with milder symptoms.

A 2019 meta-analysis in Complementary Therapies in Medicine pooled four randomized trials with 180 participants and concluded that elderberry substantially reduced upper respiratory symptoms. That sounds strong, but 180 people is a small evidence base, and the trials used different products.

Our read: the direction of the evidence is positive and consistent. Elderberry looks like a reasonable thing to take at the first sign of a cold. It is not a shield.

🤒 Flu: early studies, promising but old

Two small trials from the 1990s and 2000s, each with about 60 people or fewer, found that elderberry syrup started within 48 hours of flu symptoms helped people feel better several days sooner than placebo. Those results are the source of many of the big claims you see online. The U.S. National Center for Complementary and Integrative Health (NCCIH) summarizes the evidence cautiously: elderberry may relieve flu symptoms, but the studies are small and more research is needed.

Important: elderberry is not a substitute for a flu vaccine or for antiviral medicine. If you are in a high-risk group, pregnant, over 65, or have a chronic illness, call your doctor early when flu symptoms start, because prescription antivirals work best in the first two days.

🛡️ “Immune boosting”: the claim that outruns the data

Taking elderberry every day all winter to avoid getting sick is popular, but that is exactly what the travel trial tested, and it did not reduce the number of colds. There is no good evidence that daily elderberry prevents colds or flu. If you want to lower your odds, the unglamorous basics still win: vaccination, sleep, hand washing, and staying home when you are sick.

🍯 Honey: the remedy with the best evidence

For a cough, honey has better evidence than most supplements. A Cochrane review found that honey probably eases cough symptoms in children better than no treatment, and about as well as some common over-the-counter cough medicines. A teaspoon on its own or stirred into warm water or tea at bedtime is the usual approach. Never give honey to a baby under 12 months old, because of the risk of infant botulism.

🌼 Echinacea and blends

Echinacea is the other big name in cold season. The research is a mixed bag: some products seem to shorten colds slightly and others show no effect, which is not surprising when different species, plant parts and preparations are sold under the same name. Many immune tinctures combine echinacea with goldenseal. Goldenseal can interfere with how the body processes many prescription medicines, so if you take any regular medication, check with a pharmacist before using a blend that contains it.

How to use elderberry sensibly

• Start early. The trials that found a benefit started within a day or two of symptoms, or before exposure. Starting on day five is unlikely to do much.
• Follow the label dose. Trials used anywhere from capsules of 300 mg extract two or three times a day to tablespoons of syrup several times a day. Liquid extracts are measured in drops or millilitres, so read the serving size.
• Use it short term. A week or two during an illness is how it was studied. There is little data on taking it every day for months.
• Watch the sugar. Many syrups and gummies are mostly sugar. An unsweetened or glycerin-based extract avoids that.
• Know when to stop self-treating. Trouble breathing, chest pain, a fever over 103°F (39.4°C), or symptoms that improve and then get worse all need a doctor.

Who should skip elderberry or ask first

• Pregnant or breastfeeding. There is not enough safety information, so ask your doctor or midwife first.
• People with autoimmune conditions or on immune-suppressing drugs. Because elderberry may stimulate parts of the immune system, check with your specialist.
• Anyone taking diuretics, diabetes medication or laxatives, since elderberry may add to their effects.
• Children. Use products made for children, at children’s doses, and ask your pediatrician. Honey-based syrups are never for babies under one.

The honest bottom line

Elderberry has earned a place in the medicine cabinet as a short-term, start-it-early remedy. The best evidence suggests it may take a day or two off a cold and ease flu symptoms, though the trials are small. It has not been shown to prevent illness, so skip the all-winter habit and put that money toward sleep and a flu shot. And do not overlook the humble option: for a cough, a spoonful of honey is one of the best-supported natural remedies there is.

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Studies and sources

• Tiralongo E et al. (2016). Elderberry supplementation reduces cold duration and symptoms in air-travelers: a randomized, double-blind placebo-controlled clinical trial. Nutrients.
• Hawkins J et al. (2019). Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: a meta-analysis of randomized, controlled clinical trials. Complementary Therapies in Medicine.
• Elderberry: usefulness and safety. NCCIH.
• Elderberry as a dietary supplement for immune health. Operation Supplement Safety (U.S. Department of Defense).
• Honey for acute cough in children. Cochrane Library.
• Goldenseal: usefulness and safety, including drug interactions. NCCIH.

This article is for general education and is not medical advice. Talk to your doctor or pharmacist before starting a supplement, especially if you take medication or have a health condition. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.