Remedy · fruit

Elderberry for colds and flu: what the evidence says

A popular syrup with a short, conflicting trial record. Early small studies suggested faster recovery from flu; the most carefully run recent trial found none. Raw berries are toxic until cooked.

By the editors of Alimentotherapy Last reviewed October 18, 2026 3 min read Not medical advice

Elderberry

Sambucus nigra

Best-supported use: Flu symptoms

EvidenceLimitedbest use

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The short answer

The evidence for elderberry is limited and conflicting: early small trials of elderberry syrup reported flu symptoms easing about four days sooner, but a 2020 placebo-controlled trial in emergency-room patients with confirmed flu found no difference in how long symptoms lasted Zakay 2004; Macknin 2020. Raw or unripe elderberries, leaves and stems contain cyanide-producing compounds, so only cooked or commercially prepared products are safe to eat NCCIH.

The evidence, use by use

Each claim graded on human studies only. How we grade

Use	Grade	What the research found
Flu symptoms	Limited	A small Norwegian trial found symptoms relieved about four days earlier with 15 ml of elderberry syrup four times a day for five days. A 2020 trial of 87 patients with lab-confirmed flu found no benefit on duration or severity. Zakay 2004; Macknin 2020
Cold duration and symptoms	Limited	In a trial of 312 air travelers, elderberry did not significantly reduce the number of colds, but the colds that did occur were shorter and milder than in the placebo group. Tiralongo 2016
Upper respiratory symptoms in general	Limited	A 2019 meta-analysis reported a large effect, but it pooled only 180 participants from a handful of small trials, and the larger 2020 flu trial was published after it. Hawkins 2019; Macknin 2020
COVID-19	Not supported	There is no good evidence for elderberry against COVID-19, and the FDA and FTC have acted against companies marketing it that way. NCCIH

Why the trials disagree

The early elderberry trials were small, and several were run with a single commercial extract. In the 2004 Norwegian study, adults with flu-like symptoms for 48 hours or less took 15 ml of elderberry syrup or a placebo syrup four times a day for five days, and the elderberry group recovered about four days sooner and used less rescue medication Zakay 2004. The authors themselves said the result needed a larger study.

The 2020 trial tried to be that study. It enrolled 87 patients over age four with flu confirmed by PCR test, gave the same type of extract, and was powered to detect a two-day benefit. Symptoms lasted just as long in both groups Macknin 2020. One trial does not settle the question, but it is the best-controlled test so far, and it pulls the grade down to limited.

Cooking elderberries safely

Safety

Raw or unripe elderberries and the leaves, stems and bark of the elder tree contain cyanide-producing substances that can cause nausea, vomiting and severe diarrhea. Cooking the ripe berries eliminates the toxin NCCIH. Never make syrup from raw berries, and strip berries from their stems before cooking.

Home syrups are usually made by simmering destemmed ripe berries in water, straining, and sweetening with honey or sugar. Remember that honey should not be given to babies under one year old. If you would rather buy dried berries or a prepared syrup, iHerb sells both; check that a product lists Sambucus nigra fruit and not just flavoring.

What actually helps with flu

Rest, fluids and fever control are the basics. For people at higher risk of complications, prescription antiviral medicine works best when started early, so a fast call to a clinician matters more than any syrup. Elderberry is a reasonable thing to try alongside, not instead of, that advice.

Before you try it: safety and interactions

Who should avoid it or ask first

You take any regular medicine: talk with your clinician first, since little is known about interactions.
You are tempted to use raw or homemade-from-raw berries: cook them first.

Possible side effects

Commercial cooked products are generally tolerated in short trials.
Nausea, vomiting and severe diarrhea from raw or unripe berries, leaves or stems.

Pregnancy and breastfeeding

Little is known about whether elderberry is safe for health purposes during pregnancy or while breastfeeding, so check with your clinician. NCCIH

Medicine interactions

We found no well-documented medicine interactions for elderberry at food amounts. That is not proof there are none: tell your pharmacist about any herb or supplement you take.

Check another food or medicine in the interactions list.

Common questions

Does elderberry syrup shorten the flu?

The evidence is conflicting. A small 2004 trial found flu symptoms eased about four days sooner with elderberry syrup, but a 2020 placebo-controlled trial of 87 patients with lab-confirmed flu found no difference in how long or how badly symptoms lasted.

Are raw elderberries poisonous?

Yes. Raw or unripe elderberries, and the leaves and stems of the elder tree, contain cyanide-producing substances that can cause nausea, vomiting and severe diarrhea. Cooking ripe berries eliminates the toxin, according to NCCIH.

Sources

Primary research and government sources, each checked on the date this page was reviewed.