Elderberry

What it is

Elderberry is the fruit of the elder tree, most often the European black elder Sambucus nigra, sold as syrups, gummies, lozenges, capsules and standardised extracts. The berries are rich in anthocyanins and other polyphenols; a trial-grade extract used in one randomised study contained 300 mg of elderberry extract with 22% polyphenols and 15% anthocyanins per capsule. Raw and unripe berries and the leaves, stems and other green parts contain cyanide-producing compounds, which is why traditional preparation involves cooking. Measured levels of cyanogenic glycosides in American elderberry fruit tissues were between 0.12 and 6.38 micrograms per gram, with the highest total cyanogenic potential in stems and green berries.

What the research says

The honest summary is that the evidence is thin and uncertain rather than settled either way. A 2021 systematic review using GRADE concluded that elderberry may not reduce the risk of catching a cold, may shorten colds and influenza but with uncertain evidence, and found no support for the widely repeated claim that it triggers a cytokine storm. A 2019 meta-analysis of only 180 participants reported a large benefit for upper respiratory symptoms. A later independent randomised trial in 87 people with laboratory-confirmed influenza found no benefit at all, and a post hoc analysis suggested elderberry taken alone did worse than placebo. Elderberry is a food, not a nutrient, and the clearest documented harm comes from consuming raw or improperly prepared elder plant material.

Evidence grade: Limited evidence.

What goes wrong

In a post hoc analysis of that trial, people taking elderberry alone did worse than people taking placebo alone. (Source 1)

• Randomized trial, Very low certainty.
• Size: subgroup of 87 randomised participants who did not also take oseltamivir.
• Who: influenza patients not taking an antiviral.
• How long: 5 days of treatment.
• Result: Primary outcomes about 2 days worse with elderberry alone than with placebo alone; this was a post hoc subgroup finding in a small trial and should not be read as an established harm.
• Funding: investigator-initiated trial; no industry sponsor stated.

Post hoc analysis suggested primary outcomes with elderberry taken alone (without oseltamivir) were 2 days worse than with placebo taken alone.

Drinking juice pressed from raw elderberries together with leaves and stems caused an outbreak of acute poisoning requiring helicopter evacuation. (Source 2)

• Case series, Certainty not rated.
• Size: 11 people became ill; 8 were flown to hospital out of a gathering of 25.
• Who: adults at a gathering in Monterey County, California, in August 1983.
• How long: symptoms began within 15 minutes of drinking.
• Result: Nausea, vomiting, abdominal cramps and weakness; some dizziness and numbness; one person stuporous and hospitalised overnight; arterial blood gases and serum cyanide levels were normal in all eight; all recovered quickly.
• Funding: US government public health report (CDC MMWR, 6 April 1984)

Within 15 minutes after drinking refreshments, 11 persons began to have nausea and vomiting. The eight persons most ill reported nausea, vomiting, abdominal cramps, and weakness.

NCCIH's position is that raw or unripe elderberries and the green parts of the plant contain cyanide-producing substances that cooking removes. (Source 3)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: general public.
• How long: page last updated November 2024.
• Result: Nausea, vomiting and severe diarrhoea described; large quantities of the toxin may cause serious illness.
• Funding: US government agency (National Center for Complementary and Integrative Health)

Raw or unripe elderberries and other parts of the elder tree, such as the leaves and stem, contain poisonous cyanide-producing substances that can cause nausea, vomiting, and severe diarrhea; cooking eliminates this toxin.

What the evidence supports

A 2019 meta-analysis reported that elderberry substantially reduced upper respiratory symptoms, but it pooled only 180 participants and gave no certainty rating. (Source 4)

• Meta-analysis, Certainty not rated.
• Size: 180 participants in total; the number of included trials is not stated in the abstract.
• Who: people with cold or influenza symptoms, with vaccination status and underlying pathology examined as moderators.
• How long: not stated in the abstract.
• Result: Described as a large mean effect size; no numeric effect size, confidence interval or p value is given in the abstract, and we could not retrieve the full text.
• Funding: not stated in the abstract.

Limit of this finding: The review's own words, 'a large mean effect size', rest on just 180 participants pooled from a handful of small trials, and the same abstract states that 'there are no large-scale studies'. It reports no numeric effect size, confidence interval or p-value in the abstract and no certainty rating. A large effect measured in 180 people is easily an overestimate, and a later independent trial in 87 people with confirmed influenza found no benefit.

Supplementation with elderberry was found to substantially reduce upper respiratory symptoms.

What the evidence does not support

The same review found no evidence that elderberry overstimulates the immune system, contradicting the cytokine storm warning that circulated during COVID-19. (Source 5)

• Systematic review, Very low certainty.
• Size: three studies in which a total of 51 people were given elderberry products and cytokine production was assessed.
• Who: people given elderberry products, with cytokine production assessed ex vivo.
• How long: short-term supplementation.
• Result: No studies linking elderberry to clinical inflammatory outcomes were found; effects on inflammatory markers were present but appeared to decline with ongoing supplementation.
• Funding: not stated in the abstract.

Elderberry may be a safe option for treating viral respiratory illness, and there is no evidence that it overstimulates the immune system.

In an independent randomised trial of people with PCR-confirmed influenza, elderberry did nothing to shorten or soften the illness. (Source 1)

• Randomized trial, Certainty not rated.
• Size: 87 participants (44 placebo, 43 elderberry)
• Who: emergency department patients over age four with under 48 hours of at least two moderate influenza symptoms and a positive PCR test; average age 25.
• How long: 5 days of treatment, with follow-up to full symptom resolution.
• Result: Days to all symptoms none or mild: 4.9 (SD 2.8) placebo versus 5.3 (SD 3.6) elderberry, p = 0.57; days to complete resolution 8.7 (SD 3.8) versus 8.6 (SD 3.9), p = 0.87.
• Funding: investigator-initiated, FDA-approved Investigational New Drug trial (NCT03410862); no industry sponsor stated in the abstract.

The average number of days to reach all symptoms none or mild for 21.5 h in the placebo group was 4.9 ± 2.8 days compared to 5.3 ± 3.6 in the elderberry group (p = 0.57).

US regulators have acted against companies marketing elderberry with unsubstantiated COVID-19 claims. (Source 3)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: general public and supplement marketers.
• How long: page last updated November 2024.
• Result: No effect estimate; a statement of regulatory action and of insufficient evidence for uses beyond respiratory symptoms.
• Funding: US government agency (NCCIH), reporting FDA and FTC action.

The U.S. Food and Drug Administration (FDA) and Federal Trade Commission have taken action against companies that marketed elderberry products with unsubstantiated claims of effectiveness for COVID-19.

Where the evidence is mixed

A 2021 systematic review with GRADE found elderberry may not reduce the risk of catching a cold, and rated the evidence on duration and severity as uncertain. (Source 5)

• Systematic review, Very low certainty.
• Size: five randomised trials from 1,187 screened records; the prevention trial had 312 participants and the influenza treatment trials 151.
• Who: adults and children taking elderberry preparations for prevention or treatment of viral respiratory illness.
• How long: days to weeks, depending on trial.
• Result: Prevention of colds RR 0.69 (95% CI 0.34 to 1.39); cold duration MD -2.13 days (95% CI -4.16 to -0.10); cold severity MD -13.69 (95% CI -24.54 to -2.84); time to influenza recovery MD -2.68 days (95% CI -5.23 to -0.13), with the review rating certainty from moderate to very low.
• Funding: not stated in the abstract.

Elderberry may not reduce the risk of developing the common cold; it may reduce the duration and severity of colds, but the evidence is uncertain.

An industry-funded trial in 312 air travellers did not show significantly fewer colds, but reported shorter and less severe colds among those who caught one. (Source 6)

• Randomized trial, Certainty not rated.
• Size: 312 economy class passengers.
• Who: adults flying from Australia to an overseas destination.
• How long: supplementation around intercontinental travel, with diaries and surveys to 4 days after travel.
• Result: Cold episodes 17 placebo versus 12 elderberry, reported as not significant (the abstract prints p = 0.4 and the Results section prints p = 0.2 for the same comparison); cold episode days 117 versus 57 (p = 0.02); average symptom score 583 versus 247 (p = 0.05)
• Funding: industry-funded: the study was funded by Iprona AG, Italy, which supplied the capsules and was partially involved in the design.

Limit of this finding: The paper contradicts itself on this comparison: its abstract prints p = 0.4 while its Results section prints p = 0.2 for the same 17-versus-12 count of cold episodes. Both values are above the 0.05 threshold the trial used, so the conclusion that there were not significantly fewer colds holds either way, but no single p-value for this comparison can be treated as settled. Note also that the two results the trial does call significant (duration and symptom score) are counted only among the people who actually caught a cold, a much smaller group than the 312 randomised.

Most cold episodes occurred in the placebo group (17 vs. 12), however the difference was not significant (p = 0.4).

The toxic potential comes from the green parts of the plant rather than the ripe berries, and measured cyanogenic glycoside levels in fruit were low. (Source 7)

• Lab study in cells, Certainty not rated.
• Size: multiple American elderberry cultivars and tissues, plus commercial juice.
• Who: not human; laboratory analysis of plant tissues and commercial juice by LC-MS/MS and a picrate paper test.
• How long: not applicable.
• Result: Cyanogenic glycosides 0.12-6.38 micrograms per gram in fruit tissues, 0.29-2.36 micrograms per millilitre in pressed juice, 0.12-2.38 micrograms per gram in seeds; none quantifiable in commercial juice; total cyanogenic potential highest in stems and green berries.
• Funding: not stated in the abstract.

Results showed no quantifiable trace of CNGs in commercial AE juice. Levels of CNGs found in various fruit tissues of AE cultivars studied ranged from between 0.12 and 6.38 µg/g.

Where the research disagrees

Whether elderberry shortens influenza

• Hawkins and colleagues, meta-analysis in Complementary Therapies in Medicine, 2019, meta-analysis of randomised trials pooling only 180 participants, with no certainty rating and no numeric effect size in the abstract: Supplementation with elderberry was found to substantially reduce upper respiratory symptoms. (Source 4)
• Macknin and colleagues, randomised trial in the Journal of General Internal Medicine, 2020, investigator-initiated double-blind randomised placebo-controlled trial in 87 patients with PCR-confirmed influenza: We found no evidence that elderberry benefits the duration or severity of influenza. (Source 1)

How much

• Reference intake: No reference intake or recommended daily amount has been set for elderberry by any body we could reach. It is a food and a herbal preparation, not an essential nutrient, and the systematic review evidence is not firm enough to support a defined amount. (Source 5)
• Upper limit: No tolerable upper intake level or acceptable daily intake has been set. The limiting factor described by NCCIH is not the ripe cooked berry but the cyanide-producing substances in raw or unripe berries and green plant parts, where large quantities may cause serious illness (page updated November 2024). (Source 3)
• Studied: A 2020 influenza trial gave children aged 5 to 12 years 15 ml (5.7 g) of elderberry extract twice a day for 5 days, and people over 12 the same 15 ml four times a day for 5 days. (Source 1)
• Studied: A 2016 air-travel trial used capsules containing 300 mg of elderberry extract standardised to 22% polyphenols and 15% anthocyanins. (Source 6)

A common belief, and what the research shows

The belief: Elderberry dangerously overstimulates the immune system and can cause a cytokine storm, so it should be avoided during a viral illness.

What the research shows: A systematic review that looked specifically for this found nothing to support it. The reviewers reported that they "did not find any studies linking elderberry to clinical inflammatory outcomes" and concluded that "Elderberry may be a safe option for treating viral respiratory illness, and there is no evidence that it overstimulates the immune system." The documented poisoning risk is the opposite and more mundane: raw, unripe berries and the green parts of the elder plant contain cyanide-producing compounds, and juice pressed from berries together with leaves and branches sent eight people to hospital in 1983.

Questions and answers

What is it?

Elderberry is the fruit of the elder tree, usually the European black elder Sambucus nigra, sold as syrups, gummies, lozenges and capsules. Commercial extracts are standardised to their polyphenol and anthocyanin content. One trial used capsules with 300 mg of extract at 22% polyphenols and 15% anthocyanins. (Source 6)

What does it do in the body?

Elderberry is taken for colds and influenza. A systematic review using GRADE found it may not reduce the chance of catching a cold, and that any shortening of colds or influenza rests on uncertain evidence. It is a food rather than a nutrient and has no established role in normal body function. (Source 5)

Is it good or bad for you?

Cooked ripe elderberry preparations appear reasonably safe, and the review that looked hardest for harms found none clearly attributable to them. The benefit is uncertain: a small meta-analysis found a large effect, a better-powered independent trial found none. Raw or unripe berries and the leaves and stems are a different matter and have caused acute poisoning. (Source 5)

How do you get more of it?

People take elderberry as syrups, extracts and capsules, or eat the cooked berries. Trials have used very different forms and amounts: one influenza trial gave 15 ml (5.7 g) of extract twice daily to children aged 5 to 12 and four times daily to older patients, for five days. That is what a trial gave, not a recommendation. (Source 1)

If it is harmful, what reduces it?

The harm to avoid is not the berry itself but the cyanide-producing compounds in raw or unripe fruit and in leaves and stems, and cooking removes them. Processing also lowers them substantially: higher processing temperatures cut cyanogenic glycosides by 44% in juice and as much as 96% in liqueur and spread. (Source 3)

Why might someone be low in it or missing it?

There is no elderberry deficiency, because it is not an essential nutrient. Most people never eat it: elder fruit is seasonal, is not a staple crop, and must be cooked before it is safe, so ordinary diets contain none of it without deliberate effort. (Source 3)

Which whole foods contain it or feed it?

The whole food is the ripe, cooked berry of the elder tree, eaten as juice, syrup, jam or cordial. Commercial juice tested in one laboratory study had no quantifiable cyanogenic glycosides, while stems and green berries had the highest cyanogenic potential. (Source 7)

What happens if you do not have it?

Nothing is known to go wrong from not taking elderberry. In the influenza trial, patients on placebo recovered on the same timetable as patients on elderberry, and in the cold prevention trial the difference in episodes was not significant. (Source 1)

How can you test for it?

There is no clinical test of a person's elderberry status, because there is no deficiency to detect. Testing in this field is applied to the material rather than to people: validated LC-MS/MS and picrate paper methods are used to measure cyanogenic glycosides and total cyanogenic potential in berries, juice and other tissues. (Source 7)

References

1. Journal of General Internal Medicine. Elderberry Extract Outpatient Influenza Treatment for Emergency Room Patients Ages 5 and Above: a Randomized, Double-Blind, Placebo-Controlled Trial. 2020. PMID 32929634, DOI 10.1007/s11606-020-06170-w. Read the source
2. Morbidity and Mortality Weekly Report (CDC). Poisoning from Elderberry Juice -- California. 1984. Read the source
3. National Center for Complementary and Integrative Health (NIH). Elderberry: Usefulness and Safety. 2024. Read the source
4. Complementary Therapies in Medicine. Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trials. 2019. PMID 30670267, DOI 10.1016/j.ctim.2018.12.004. Read the source
5. BMC Complementary Medicine and Therapies. Elderberry for prevention and treatment of viral respiratory illnesses: a systematic review. 2021. PMID 33827515, DOI 10.1186/s12906-021-03283-5. Read the source
6. Nutrients. Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial. 2016. DOI 10.3390/nu8040182. Read the source
7. Molecules. Cyanogenic Glycoside Analysis in American Elderberry. 2021. PMID 33806603, DOI 10.3390/molecules26051384. Read the source