Immunity · Trend check

Elderberry: what the syrup trend gets wrong

Elderberry syrup is one of the best-selling herbal supplements in the US, and social media treats it as a winter essential. The trials behind it are small, mostly industry-funded, and the best independent one found nothing. Here is the full picture.

By Kymata Health Editorial Sources cited inline Prices checked Oct 29, 2026

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Quick answer

The quick answer

Catching colds: the largest trial (312 air travellers, industry-funded) found no significant drop in the number of colds. Total cold days were lower, but from only 29 colds.
Flu: two small trials from an extract maker reported faster recovery; the best independent trial (87 people with lab-confirmed flu) found no benefit.
Homemade syrup made from raw berries, stems or leaves can cause vomiting and severe diarrhea. Commercial products use cooked berries.
If you want something with better cold data, zinc lozenges started early have more consistent trials.

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Story

Why this trend took off

Elderberry sales jumped during the 2020 pandemic and have stayed high, helped by homemade-syrup recipes and "immune" gummies for kids. Most of the claims trace back to two small trials from the 1990s and 2000s and one air-travel study funded by an extract maker.

That is not nothing, and elderberry is generally well tolerated when prepared properly. But the gap between the confidence of the marketing and the size of the evidence is large.

In depth

The trials, one by one

Air travel, 2016 (312 people, funded by the extract maker): colds 12 vs 17 (not significant); cold days 57 vs 117; symptom scores lower. Graded C for catching colds and D for duration because the numbers were small.
Flu, 2004 (60 people, extract maker): symptoms relieved about 4 days earlier with syrup. Small and never confirmed independently (D).
Flu, 2020 (87 people with lab-confirmed flu, investigator-led, FDA investigational trial): no difference in time to mild or no symptoms (5.3 vs 4.9 days) or full resolution (8.6 vs 8.7 days). This is the most rigorous trial, and it was negative.

In depth

Homemade syrup and the cyanide problem

Raw or unripe elderberries, and the leaves, stems, bark and roots, contain compounds that release cyanide. Eating them, or syrup made without enough cooking, has caused nausea, vomiting and severe diarrhea. Commercially prepared extracts and properly cooked berries do not carry this risk.

The plan

If you still want to try it

Step 1Choose a commercial standardized extract
Look for Sambucus nigra extract with the amount per serving stated; skip homemade syrup unless you know it was cooked thoroughly from ripe berries.
Step 2Use it like the trial, not all winter
The air-travel trial used it around a single long-haul trip. There is no evidence for daily use all season.
Step 3Do not use it instead of flu care
Adults with flu symptoms in a high-risk group should call a clinician within 48 hours: prescription antivirals have far better evidence.

The stack

What to use instead (and where elderberry fits)

Zinc lozenges have the stronger cold data; elderberry is an optional extra around travel, not a daily habit. Evidence grade: A strong · B moderate · C limited · D preliminary.

01
Zinc acetate or gluconate lozenges
The one supplement with consistent trial data for a shorter cold, when it is started early. It does little to stop you catching one.
What the research shows: In three pooled zinc acetate lozenge trials (199 adults), colds were about 2.7–2.9 days shorter, against an average cold of 7 days. A 2017 meta-analysis of seven trials (575 people; PMID 28515951) found colds 33% shorter with lozenges giving more than 75 mg a day, with no extra benefit above 100 mg. The 2024 Cochrane review rated the evidence for shorter colds low certainty because trials disagreed, which is why this is a B and not an A. (PMID 27378206, PMID 28515951, PMID 38719213)
- The lozenge trials went above the US upper limit for zinc (40 mg/day from all sources, NIH Office of Dietary Supplements) for a few days only. Weeks of zinc at 50 mg/day or more can lower copper status; do not carry cold-dose zinc into a daily habit.
- Nausea and a bad taste are the common side effects. Zinc nasal sprays and gels have been linked to lasting loss of smell; lozenges dissolve in the mouth and are a different product.
- Separate zinc from quinolone or tetracycline antibiotics (take the antibiotic at least 2 hours before or 4–6 hours after) and from penicillamine.
In the studies
- Trials in the 2017 meta-analysis gave 80–92 mg of elemental zinc a day from lozenges dissolved slowly in the mouth, for up to about a week, in adults with a fresh cold.
A record of what researchers gave, in whom; not a dose for you.
Evidencemoderate (Grade B)
What to look for on the label
Lozenges (not capsules or tablets you swallow) that name zinc acetate or zinc gluconate and the elemental zinc per lozenge, with no citric acid or tartaric acid, which bind zinc in the mouth. Not a nasal spray or gel.
We only name brands we have vetted and work with; a specific pick will appear here once one is approved.
02OptionalPaid links · we earn a commission
Standardized elderberry extract
Optional. A small, industry-funded trial hints at fewer cold days after flying, but it did not cut the number of colds.
What the research shows: In 312 economy-class travellers, colds were not significantly less common with elderberry (12 vs 17), though total cold days were lower (57 vs 117) from only 29 colds. The extract maker funded the trial and supplied the capsules. A later independent trial in 87 people with lab-confirmed flu found no benefit at all. (PMID 27023596, PMID 32929634)
- Raw or unripe berries, leaves, stems and bark can cause nausea, vomiting and severe diarrhea; use commercially prepared products only.
- Little is known about safety in pregnancy and breastfeeding. Ask first if you take diabetes medicines or diuretics.
In the studies
- The air-travel trial gave 600 mg/day of elderberry extract for the days before travel and 900 mg/day while travelling and for a few days after.
A record of what researchers gave, in whom; not a dose for you.
Evidencelimited (Grade C)
Quick pick · HerbsPro
Brands that pay us are shown first in this list.
NOW Foods Elderberry, 500 mg, 60 Veg Caps
1 veg capsule: 500 mg elderberry fruit 10:1 concentrate (Sambucus nigra)
$8.92price checked Oct 14, 2026 on HerbsPro’s site
Shop at HerbsPro (paid link, opens in new tab)
We may earn a commission if you buy through these links. That never changes a rank. See how partner links work.

Listed picks above total $8.92 at one-time prices on the brands' own sites; most hold about a month of servings at the label's serving size.

Left out

What we left out, and why

Elderberry gummies for kids: Children’s products usually contain a fraction of the extract used in trials, plus sugar. There are no good trials in young children for colds, and little is known about safety in pregnancy and breastfeeding.
The "cytokine storm" worry: Early in the pandemic, posts warned elderberry might overstimulate the immune system. There is no human evidence of harm from that; there is also no evidence it helps COVID-19.

Safety

Safety and interactions

Never eat raw or unripe elderberries, leaves, stems or bark. Use commercially prepared products.
Little is known about safety in pregnancy and breastfeeding. Ask first if you take diabetes medicines, diuretics or cancer medicines, or have an autoimmune condition.
See a clinician promptly for trouble breathing, chest pain, confusion, a fever lasting more than 4 days, symptoms that improve and then get worse, or symptoms lasting more than 10 days (CDC guidance).
Babies, adults over 65, pregnant women and anyone with asthma, COPD, heart disease, diabetes or a weakened immune system should call early: flu and COVID-19 have prescription options that work best in the first 48 hours.
Not medical advice. Supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease.

Questions

Frequently asked questions

Does elderberry work for colds?

The largest trial, in 312 air travellers and funded by the extract maker, found no significant drop in the number of colds. Cold days were fewer, but from only 29 colds in total. The evidence is weak.

Does elderberry help with the flu?

Two small trials funded by an extract maker reported faster recovery. The most rigorous independent trial, in 87 people with lab-confirmed flu, found no benefit.

Is homemade elderberry syrup safe?

Only if made from ripe berries that are thoroughly cooked. Raw berries, stems and leaves contain compounds that release cyanide and have caused vomiting and severe diarrhea.

How much elderberry did the trial use?

The air-travel trial gave 600 mg/day of extract before the flight and 900 mg/day during and after travel. That is a record of the trial, not a proven dose.

Sources

Studies were checked on PubMed on Oct 31, 2026. Product prices come from each brand's own site, read on Oct 29, 2026; each product shows the date its price was read.

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Elderberry: what the syrup trend gets wrong

Zinc acetate or gluconate lozenges

Standardized elderberry extract

NOW Foods Elderberry, 500 mg, 60 Veg Caps