Elderberry

Is elderberry safe?

Bought as a syrup, gummy or extract made from cooked ripe berries, elderberry appears safe for most adults. A 2021 systematic review of five randomised trials found few side effects, though the trials recorded them poorly. The two real problems are the raw plant and the product. Raw or unripe berries, leaves and stems contain compounds that release cyanide, and a 2022 lab study found that only 10 of 31 supplements sold as elderberry contained nothing else.

People who are pregnant, breastfeeding, living with an autoimmune disease or taking immunosuppressants have less evidence to go on, and should ask a doctor first.

Why raw elderberries make people sick

All parts of the elder tree contain cyanogenic glycosides, mainly one called sambunigrin, which can release hydrogen cyanide. The levels differ a lot by plant part. A 2017 European study found the least in the berries, about 0.1 to 0.6 micrograms per gram, with much more in leaves. A 2021 study of American elderberry found none in commercial elderberry juice and the most in stems and green berries. NCCIH sums it up: raw or unripe berries, leaves and stems can cause nausea, vomiting and severe diarrhoea, and cooking eliminates the toxin.

The best-known case is from August 1983, at a gathering in Monterey County, California. Staff pressed wild elderberries together with their leaves and branches into juice. Of 25 people at the gathering, 11 fell ill with nausea and vomiting; eight were flown to hospital by helicopter with cramps, weakness, dizziness and numbness, and one was stuporous. All recovered quickly, according to the CDC report, which advised never crushing leaves and stems into juice.

Store-bought products are made from processed berries, so this risk applies mainly to foragers and homemade syrups and tinctures.

What is really in elderberry supplements?

Demand for elderberry extract surged while raw berries ran short and costs rose, according to a 2023 review, and that is when adulteration appeared. A 2022 study tested 31 supplements claiming to contain European elderberry extract. Only 10 matched the label and contained just elderberry. The most common substitute was black rice extract, which carries similar purple anthocyanin pigments; others contained purple carrot or elder flowers instead of berries. The 2023 review, drawing also on data from suppliers, manufacturers and testing labs, concluded that adulteration of elderberry extracts is quite common.

A 2024 review of 78 publications put the figure lower, at 17% of 695 elderberry samples of all kinds, and found licensed herbal medicines less often adulterated than supplements. Black rice is not dangerous, but it means the product is not what you paid for, and any effect seen in trials may not apply.

Contamination is the other issue. FDA recall records include:

Who should be careful

• Pregnancy and breastfeeding: NCCIH says little is known about safety, and a 2021 review in the Journal of Primary Health Care found the evidence insufficient.
• Autoimmune disease: the same review said elderberry may worsen symptoms of autoimmune diseases and is best avoided. This rests on its effect on the immune system rather than on reported cases.
• Immunosuppressants: if you take them after a transplant or for an inflammatory disease, talk to your doctor before taking it, as it could in theory work against these drugs.
• Children: ask your child's doctor before giving it, and never give homemade raw preparations.

Elderberry has no other major known drug interactions. During the pandemic there was concern that it might trigger a cytokine storm, but the 2021 systematic review found no evidence that it overstimulates the immune system.

Does it work?

Modestly at best. The 2021 review concluded that elderberry may shorten colds and flu, but the evidence is uncertain and it may not prevent colds at all. The FDA and the Federal Trade Commission have acted against companies that claimed elderberry could prevent or treat COVID-19. Our pages on vitamin C and zinc cover the other common cold supplements.

How to use it more safely

1. Buy from brands that test identity. Look for USP VerifiedThird-party testingTesting of a supplement by an independent lab to check that it contains what the label says and is free of set contaminants.More in the glossary, NSF or a supplier that publishes anthocyanin profile testing, which is how black rice substitution is detected.
2. If you make syrup at home, use only ripe, dark berries, remove every stem and leaf, cook thoroughly and keep it refrigerated.
3. Do not forage elder you cannot identify. Several Sambucus species grow wild, and the 1983 cluster involved wild elder picked locally in California.
4. Stop and get help if nausea, vomiting or dizziness start after a homemade preparation.

How we scored it

Organ toxicity (90) and interactions (85) are strong, with no credible organ injury reports and no major known drug interactions. Dose safety (82) reflects clean trial data for commercial products but real toxicity from raw plant parts. Regulatory actions (82) cover COVID-19 claims and contamination recalls rather than bans. Product quality (48) is the weak point: most extract supplements in a 2022 authenticity test were not pure elderberry, and recalls for Salmonella and botulism risk continue.