Elderberry

Sambucus nigra L. was named by Linnaeus in Species Plantarum in 1753, and Kew’s Plants of the World Online (POWO) accepts it in the family Viburnaceae, order Dipsacales. Other references give other family names for the same plant. Mrs Grieve’s A Modern Herbal (1931) and the USDA PLANTS Database place it in the honeysuckle family, Caprifoliaceae, while the Woodland Trust and the European Food Safety Authority compendium quoted by EMA use the moschatel family, Adoxaceae. The plant has not changed; botanists have redrawn the family boundaries around it. POWO lists it as native from Portugal, Spain, Ireland, and Great Britain across Europe to Türkiye, the Caucasus, Lebanon and Syria, Iraq, and Iran, and as introduced in places as far apart as Argentina, Brazil, Chile, Australia, New Zealand, Pakistan, and parts of eastern North America. POWO records it as used for food, animal food, and medicine, and as a poison, a fair summary of the plant’s double life. The Woodland Trust notes that it grows in woodland, scrub, wasteland, and hedgerows, and often appears near rabbit warrens and badger setts, where animals spread the seeds in their droppings.

Elder is usually seen as a large shrub, but the Woodland Trust says mature trees can reach about 15 meters and live for around 60 years. It has a short trunk, grey-brown, corky, furrowed bark, and relatively few branches, and its twigs are hollow or filled with soft white pith, which is why the stems were once made into pipes and pop-guns (Grieve). The leaves are opposite and pinnate, with five to seven oval, toothed leaflets that smell unpleasant when bruised. From late May the plant carries flat flower heads 10 to 30 cm across, made of many tiny, creamy, highly scented five-petaled flowers; Grieve noted that in England the flowering season lasts only about three weeks in June. Each pollinated flower becomes a small, sour, purple-black berry that ripens from late summer into autumn, in heavy, drooping bunches. EMA’s assessment report describes the dried fruit as a wrinkled, roughly spherical drupe about 0.5 cm across that usually holds three small stones, each containing a seed. Birds and mammals eat the berries, dormice and bank voles eat both flowers and fruit, and many moth caterpillars feed on the leaves (Woodland Trust).

The berries’ color comes from anthocyanins. EMA’s 2014 assessment report, drawing on older analyses, gives 1 to 8 mg of anthocyanins per gram of fresh fruit, rising with ripeness, with two pigments dominating: cyanidin-3-glucoside, about two-thirds of the total, and cyanidin-3-sambubioside, about one-third. The fruit also contains flavonols such as rutin, isoquercitrin, and hyperoside, about 0.01% essential oil, up to 7.5% glucose and fructose, organic acids, pectin, potassium, and 18 to 26 mg of vitamin C per 100 g. Less welcome are the plant’s defensive compounds. Elder leaves contain cyanogenic glycosides, including sambunigrin, prunasin, zierin, and holocalin, which can release hydrogen cyanide; the EFSA compendium cited by EMA gives about 3 to 17 mg of hydrogen cyanide per 100 g of fresh leaf and about 3 mg per 100 g of fruit. Seeds and fresh berries contain lectins, proteins that bind to sugars on cell surfaces, and the bark contains a lectin called nigrin b that resembles ricin in structure and activity, although it is less toxic. The dried flowers are a separate herbal drug with their own European Pharmacopoeia monograph.

Elderberry labels hide a tangle of related plants. The USDA PLANTS Database treats American elder as a subspecies, Sambucus nigra subsp. canadensis, the American black elderberry, which is why US sources sometimes describe black elderberry as native to North America; Kew’s POWO instead keeps Sambucus canadensis as a separate species, native from North America to Venezuela and Bolivia. The 2023 adulterants bulletin lists the elder berries found in commerce as European elder, American elder, blue elder (S. cerulea, also called S. nigra subsp. cerulea), and dwarf elder (S. ebulus). Memorial Sloan Kettering Cancer Center (MSKCC) notes that American and blue elder berries have similar chemistry, but European elder is the type most studied and used in supplements, and almost every clinical trial described on this page used S. nigra extracts. The native western US elder involved in the 1983 California poisoning, which the CDC report called Sambucus mexicana, has berries that the report describes as edible when mature and commonly cooked into pies and jams, while its fresh leaves, flowers, bark, young buds, and roots contain a bitter alkaloid and a glucoside that can produce hydrocyanic acid. Correct identification, full ripeness, and removing every stem matter whichever elder ends up in the basket.

Elder is one of Europe’s most storied plants, and Grieve’s A Modern Herbal (1931) gathers much of its lore. The English name traces to the Anglo-Saxon aeld, fire, because the soft pith pushes out of young stems to leave tubes for blowing up a fire, which also gave the old names pipe tree and bore tree. The genus name Sambucus appears in Pliny and may come from the sambuca, an ancient musical instrument, although Grieve doubted the link because the sambuca was a stringed instrument and elder wood would make a wind instrument. In Denmark a dryad called Hylde-Moer, the Elder-tree Mother, was said to live in the tree; permission had to be asked before cutting it, and she was believed to haunt the owners of furniture made from its wood. A medieval belief held that Judas hanged himself on an elder, a story echoed in Shakespeare’s Love’s Labour’s Lost, and the tree became an emblem of sorrow and death. Yet elders were also planted near English cottages for protection against witches, and the Woodland Trust records the belief that an elder planted by the house kept the Devil away. Gypsy custom, Grieve wrote, forbade burning its wood on camp fires.

Medicinal use is just as old. Grieve records that the Romans used elder and dwarf elder in medicine, as Pliny noted, that both were employed by early English and Welsh healers and at the medieval medical school of Salerno, and that the use of the bark as a purgative went back to Hippocrates. The seventeenth century was elder’s high point. In 1644 an English translation appeared of The Anatomie of the Elder by the physician Martin Blockwich, a treatise of some 230 pages that prescribed elder in every form from rob and syrup to tincture, oil, vinegar, and poultice for some seventy diseases or groups of diseases. The diarist John Evelyn wrote that if the medicinal properties of its leaves, bark, and berries were fully known, he could not tell what a countryman could ail for which he might not fetch a remedy from every hedge. Elder was called “the medicine chest of the country people,” and the great physician Boerhaave was said never to pass one without raising his hat. Grieve also makes clear which parts were harsh: the bark was a strong purgative and, in large doses, an emetic, and juice of the root caused vomiting, while the flowers and ripe berries were the gentler medicines.

Kitchen and pharmacy overlapped. Grieve describes elderberry rob, five pounds of ripe crushed berries simmered with a pound of sugar to the thickness of honey, taken a tablespoon or two in hot water at night to promote sweating and soothe the chest. It was official in the British Pharmacopoeia, renamed Succus Sambuci spissatus in 1788, and dropped in 1809. EMA’s assessment report adds that elderberry syrup was used against colds in parts of Europe including England and Holland, that a decoction of dried berries was used as a laxative in Germany, and that elderberry juice in port wine was taken to induce sweating. Elderberry wine, drunk hot at bedtime, was a country cold remedy, and Kent had whole orchards of elder grown for wine-makers. The juice was also used to fake port, a practice so widespread that Portugal banned it in 1747, along with growing the trees. Elderflower water was an official British preparation, used mainly as a base for eye and skin lotions, and Grieve recommended a strong, hot infusion of elderflower and peppermint, drunk in bed, at the first sign of influenza, a claim no one has tested in a trial.

The modern supplement story began in Israel. In the 1990s Zakay-Rones and colleagues reported that a standardized extract, Sambucol, inhibited many influenza strains in the laboratory and, in a small trial during a 1993 influenza B outbreak on a kibbutz, appeared to speed recovery. More trials followed, and so did demand. Macknin and colleagues noted that US elderberry sales more than doubled from 2017 to 2018, to over 100 million dollars, and the 2023 adulterants bulletin, citing the American Botanical Council’s market data, reported that elderberry was the top-selling herbal supplement ingredient in the US mass market in 2021, with combined sales of about 305 million dollars, before a 10% decline in 2022. Marketing claims drew regulators’ attention. MSKCC notes that the US Food and Drug Administration (FDA) has halted unsubstantiated claims that elderberry prevents or treats AIDS, diabetes, flu, and COVID-19, and NCCIH reports that the FDA and the Federal Trade Commission took action against companies marketing elderberry for COVID-19. In Europe, EMA’s herbal committee adopted a monograph on elderflower in 2008, revised it in 2018, and in 2014 issued a public statement, rather than a monograph, on the berry.

Most of elderberry’s plausible mechanisms come from laboratory work. In the 1995 Zakay-Rones study, Sambucol reduced hemagglutination, the clumping of red blood cells that influenza virus causes, and inhibited replication of several human influenza A (H1N1 and H3N2) and influenza B strains, as well as swine and turkey strains, in cultured dog kidney cells. MSKCC summarizes later work in which elderberry flavonoids bound to H1N1 virus particles and blocked their recognition of and entry into host cells. EMA’s assessment adds that methylated and esterified flavonoids may contribute, and mentions a small experiment in four chimpanzees in which flu-like symptoms were reduced after elderberry syrup. How much of this applies in people is unclear. EMA’s review of absorption studies found that elderberry anthocyanins can be absorbed intact, as glycosides, but at low rates, with most of the absorbed compounds excreted in urine within about four hours. Antiviral activity in a dish shows that an effect is plausible; it does not establish a dose, prove that enough reaches the airways, or show that elderberry beats rest and fluids, which is what clinical trials have to answer.

Elderberry’s effect on the immune system is where the COVID-era worry came from. In a 2001 laboratory study, Barak and colleagues exposed monocytes, a type of white blood cell, from 12 healthy donors to Sambucol products and found large increases in the inflammatory messengers IL-1β, TNF-α, IL-6, and IL-8, up to about 45-fold for TNF-α, which they presented as immune activation. During the pandemic, findings like this prompted concern that elderberry might tip infected people into a cytokine storm, an overwhelming inflammatory response. Wieland and colleagues looked for such harm in their 2021 systematic review and found no studies linking elderberry to clinical inflammatory outcomes. Three studies had measured cytokines in people after they took elderberry: a randomized trial in 52 postmenopausal women found no difference from placebo in CRP, TNF-α, or IL-6 after 12 weeks; 22 volunteers drinking dwarf elder (Sambucus ebulus) tea for 30 days had lower CRP and IL-1β; and in a small, poorly described study a single dose of elderberry tincture lowered IL-1 and, briefly, TNF-α, as did the painkiller diclofenac. EMA’s 2014 assessment judged the evidence for any immune-modulating effect insufficient. Test-tube stimulation has not translated into documented harm, and “immune support” on a label is a marketing phrase, not a measured outcome.

The plant’s toxicity has a clearer mechanism. Cyanogenic glycosides are harmless while intact, but when plant tissue is crushed, or when the glycosides meet the enzyme β-glucosidase in the gut, they break down and release hydrogen cyanide (EMA). Because hydrogen cyanide is volatile, heating berries or juice drives it off, which is why EMA concluded that heat treatment removes the small amount the seeds can release and that ripe fruit is safe to eat cooked or dried. Lectins in seeds, unripe berries, and branches are linked to stomach upset, and the CDC report on the 1983 outbreak also pointed to a bitter alkaloid in the leaves and bark. The eight people taken to hospital in that outbreak had normal serum cyanide levels, a reminder that cyanide may not be the whole story. Elderberry’s other reported effects are mostly laboratory findings. MSKCC lists blood-sugar-lowering activity, including activation of the PPAR-γ receptor by compounds from elderflowers, a diuretic effect in rats, and laxative effects in clinical studies of a multi-herb product. None of these has been tested well enough in people to guide treatment.

Elderflower is the part with official European recognition. EMA’s herbal committee concluded that dried elderflower, taken as a tea, and two alcoholic preparations can be used to relieve early symptoms of the common cold, on the basis of long-standing use: at least 30 years of safe use, including 15 years within the EU, with plausible effectiveness. The committee also noted the lack of clinical studies with elderflower, so this is a traditional-use listing, not proof from trials. It applies to adults and adolescents over 12, and EMA advises seeing a doctor if symptoms worsen or last longer than a week, or if shortness of breath, fever, or purulent sputum develops. This matches centuries of practice. Grieve described hot elderflower tea at bedtime as a good old-fashioned remedy for colds and throat troubles, valued for inducing free perspiration. No modern trial has tested elderflower tea on its own, so the berry studies below should not be borrowed to support the flower, or the other way round. Elderflower cordials and fritters, made from the same blossoms, are food traditions rather than remedies.

For influenza, the first trials were small and positive. Zakay-Rones and colleagues (1995) tested Sambucol during an influenza B outbreak on an Israeli kibbutz in 1993: 93.3% of the elderberry group had a significant improvement in symptoms, including fever, within two days, while 91.7% of the placebo group improved within six days, and nearly 90% of the elderberry group felt completely cured within two to three days. The 2021 systematic review counted only 27 participants analyzed and rated the trial at unclear risk of bias because randomization was not described. In the 2004 follow-up, 60 adults aged 18 to 54 in Norway who had flu-like symptoms for 48 hours or less took 15 ml of elderberry or placebo syrup four times a day for five days; symptoms were relieved on average four days earlier with elderberry, rescue medicines were used less, and the authors asked for a larger study to confirm the result. A 2009 trial in China gave 64 adults lozenges with 175 mg of elderberry extract or placebo four times a day for two days, but did not report overall illness duration. Pooling the two Sambucol trials, the 2021 review found recovery nearly three days faster, with very low certainty and very inconsistent results.

The best-designed influenza trial so far was negative. Macknin and colleagues (Journal of General Internal Medicine 2020), in a registered, placebo-controlled trial, enrolled 87 patients aged 5 and older at three Midwestern emergency departments between January 2018 and April 2019, all with influenza confirmed by PCR test and at least two moderate symptoms for less than 48 hours. They took elderberry extract, 15 ml (5.7 g) twice a day for children aged 5 to 12 and four times a day for older patients, or placebo, for five days, and could also choose the antiviral oseltamivir (Tamiflu). Symptoms became mild after an average of 5.3 days with elderberry and 4.9 days with placebo, and resolved completely after 8.6 and 8.7 days, no meaningful difference, even though the trial was large enough to detect a two-day benefit. In a post hoc analysis, people taking elderberry without oseltamivir did about two days worse than those taking placebo alone. The authors noted that their results contradicted earlier studies. In a separate trial of 420 people, summarized in the 2021 review, a hot drink combining echinacea and elderberry performed about as well as oseltamivir by day five, but that tested a combination product, not elderberry on its own.

Evidence for colds is thinner. Tiralongo and colleagues (Nutrients 2016) randomized 312 economy-class passengers flying from Australia to overseas destinations to capsules of a membrane-filtered Sambucus nigra extract or placebo: 600 mg a day for ten days before travel, then 900 mg a day until four or five days after arrival. Slightly fewer people in the elderberry group caught a cold (12 versus 17), a difference that was not statistically significant, but the colds that did occur were shorter (57 versus 117 total cold-episode days) and less severe. The extract’s maker sponsored the study, and the 2021 review rated these results very low certainty, concluding that elderberry may not reduce the risk of catching a cold. Pooled analyses that combine cold and flu trials look more favorable. Hawkins and colleagues (2019) analyzed 180 participants and reported a large effect on upper respiratory symptoms, and Harnett and colleagues (2020), across five studies with 936 adults, concluded that berry preparations taken within 48 hours of onset may shorten and soften cold and flu symptoms, with most participants’ symptoms falling by an average of 50% within two to four days. Neither review included the negative 2020 emergency-room trial, and the trials they pool are small and use different products.

Beyond colds and flu, the evidence is sparse. NCCIH says there is not enough information to show whether elderberry helps with any other health purpose, and that there is no good evidence for preventing or treating COVID-19. MSKCC notes that randomized trials found elderberry ineffective for improving cardiovascular risk markers and for lowering cholesterol, and EMA found no clinical studies of the traditional laxative use, despite its long history. Small studies cited by MSKCC tested elderberry within products for chronic constipation and recurrent tonsillitis in children, which says little about elderberry alone. Blending elderberry with echinacea, zinc, or vitamin C is common in cold products, and it makes each ingredient’s contribution impossible to judge. A fair summary: elderberry might modestly shorten colds and flu when started early, based on small trials, several of them sponsored by product makers; the one carefully controlled trial in laboratory-confirmed influenza found no benefit; and prevention is unproven. That makes elderberry a reasonable comfort measure for some adults, not a treatment to rely on, and not a substitute for vaccination or for antivirals when a clinician recommends them.

Most elderberry supplements are made from the fruit and sold as syrups, gummies, tablets, capsules, and lozenges, under brand names such as Sambucol, according to MSKCC. Trial doses give the only evidence-based reference points, and they apply strictly to the products tested. The Sambucol trials used 15 ml of syrup four times a day for five days, started within 48 hours of flu symptoms; the 2004 syrup contained 38% elderberry extract. The 2020 emergency-room trial used 15 ml of extract (5.7 g) four times a day for people over 12 and twice a day for children aged 5 to 12, also for five days, without benefit. The air-travel trial used 300 mg capsules of an extract standardized to 15% anthocyanins and 22% polyphenols, two a day before travel and three a day during and after it. The Chinese lozenge trial used 175 mg of extract four times a day for two days. Harnett’s review notes that the studies tested short courses of commercial products, for up to 16 days. Extracts differ in strength, sugar, and added ingredients, so a dose on one label cannot be converted into a trial dose, and results from one product may not apply to another.

Traditional preparations always involve heat or drying. EMA’s assessment concludes that ripe fruit is safe to eat cooked or dried, that heat treatment drives off the small amount of hydrogen cyanide that seeds can release, and that leaves and stems should not be crushed into preparations at all. In practice that means picking only fully ripe, dark berries, stripping them from every stem, and simmering them before making juice, syrup, or jam. An 1837 recipe quoted by EMA, the Elder Rob, used five parts ripe berries to one part sugar, boiled gently to the consistency of thick honey; handbooks cited by EMA describe a tea of about 10 g of dried berries put into cold water, heated slowly to boiling, then steeped for 5 to 10 minutes. For elderflower, EMA’s 2018 monograph gives 2 to 5 g of dried flowers in 150 ml of boiling water three times a day, or 3 to 6 g as a decoction in 200 ml of water divided into two doses; a 1:1 liquid extract is taken at 2 to 5 ml, and a 1:5 tincture at 10 to 25 ml, three times a day. These amounts are for adults and adolescents, as elderflower medicines are not recommended under age 12.

Buying a supplement raises a different question: is it really elderberry? The 2023 Botanical Adulterants Prevention Bulletin, written by Stefan Gafner and Josef Brinckmann for the nonprofit ABC-AHP-NCNPR program, reviewed seven reports and publications on elderberry extracts and products, and roughly one in six of the samples analyzed failed identity specifications. The most common fraud was partial or complete substitution with black rice extract, which can cost up to 30 times less than genuine elderberry extract; other anthocyanin-rich plant extracts and blue or purple food colors were also found, and some products had a chemical fingerprint with no anthocyanins at all. Black rice is not dangerous, but it may not deliver elderberry’s effects, and undeclared dyes carry their own risks. Look for products that name Sambucus nigra fruit or berry, state the extract and its strength, and show independent quality testing, and be wary of unusually cheap extracts. Check syrups and gummies for added sugar, especially for children or anyone managing diabetes.