Elderberry Side Effects: Who Should Not Take It, and Is Elderberry Poisonous?

Prepared elderberry products are well tolerated by most adults, and in clinical trials side effects were rare and mild. The real danger is raw elder: uncooked or unripe berries, and the leaves, stems and other parts of the plant, contain substances that can cause nausea, vomiting and severe diarrhea. Check with your doctor before taking elderberry if you're pregnant or breastfeeding, have an autoimmune condition, or take medication that suppresses the immune system, diabetes medication, diuretics or laxatives.

Elderberry is one of the most popular winter supplements, and most of the worry about it comes from one fact: the raw plant really can make you sick. Here are the side effects of elderberry products, who should skip them, which parts of the plant are poisonous, and the questions people ask most.

Common side effects of elderberry

Prepared elderberry has a good safety record in research. A 2021 systematic review of the five clinical trials of elderberry for colds and flu found no serious side effects in any of them, and the few side effects reported were similar to placebo. In the largest, a trial of 312 air travelers, no side effects could be linked to elderberry. The trials were small and didn't track minor side effects closely, so the reviewers stopped short of calling it risk-free.

When side effects do show up with a prepared product, they're usually mild:

• Stomach upset, such as nausea or loose stools. Memorial Sloan Kettering lists digestive upset as an infrequent side effect, and notes that elderberry has a mild laxative effect.
• Allergic reactions, which are rare. Stop taking it and get medical help if you notice a rash, itching, swelling of the face or lips, or trouble breathing.

Is elderberry poisonous?

Raw elder is. Properly prepared elderberry isn't. According to the National Center for Complementary and Integrative Health, raw or unripe elderberries, and the leaves and stems, contain substances that can cause nausea, vomiting and severe diarrhea, and cooking removes them. That's why a prepared product is the safe way to take elderberry.

The main culprit is sambunigrin, one of a group of plant compounds that can release cyanide in the body. Lab measurements show where it sits: elder leaves hold by far the most, dozens to hundreds of times more than ripe berries, and flowers sit in between. Stems and unripe green berries are high too. Heat breaks it down: in one study, processing cut these compounds by 44 percent in elderberry juice and by up to 96 percent in other elderberry products, and tests of commercial American elderberry juice found none at a measurable level.

The best-known case shows what raw elder can do. In 1983, at a gathering in California, 11 of 25 people fell ill within 15 minutes of drinking homemade juice made from wild elderberries that had been crushed, uncooked, together with their leaves and branches. Eight were flown by helicopter to a hospital, and all of them recovered quickly. The CDC's report noted that leaves and stems should not be crushed in when making juice.

Who should not take elderberry

Talk to your doctor before taking elderberry if you:

• Are pregnant or breastfeeding. Little is known about its safety then, and Memorial Sloan Kettering advises avoiding it.
• Have an autoimmune condition, such as rheumatoid arthritis, lupus or multiple sclerosis. In lab studies, elderberry extract made immune cells release more inflammatory signals, so in theory it could make an autoimmune condition worse. That hasn't been proven, but a small 2024 review of patient records at one dermatology clinic found flares in 11 of 19 people with two autoimmune skin conditions after they started elderberry, though it couldn't show elderberry was the cause. Harvard Health advises avoiding it if you have an autoimmune disease.
• Take medication that suppresses the immune system, for example after an organ transplant or for an autoimmune condition. Because elderberry may stimulate parts of the immune system, it could in theory work against these medicines.
• Take diabetes medication, diuretics or laxatives. Elderberry can add to their effects, as explained below.
• Want to give it to a child. Ask your pediatrician first, and use a product made for children.

Does elderberry interact with medications?

Elderberry's known interactions are few, and they're mostly about effects adding up. Memorial Sloan Kettering lists three:

• Diabetes medication. Elderberry may lower blood sugar, so together they could take it lower than intended, though how much this matters in practice hasn't been worked out.
• Diuretics (water pills). Elderberry increases urination and could add to their effect.
• Laxatives. Elderberry has a mild laxative effect of its own.

Immune-suppressing medication isn't on that list, but because of the theoretical immune effect above, it's still worth asking your doctor first. The broader rule from the National Center for Complementary and Integrative Health covers everything else: if you take any medicine, talk with your healthcare provider before using elderberry or any other herbal product. Take the bottle with you, so they can see every herb in it.

Does elderberry make you sleepy?

No. We found no evidence that elderberry causes drowsiness, and none of the main safety sources, including NCCIH and Memorial Sloan Kettering, list it as a side effect. If you feel tired, a cold or flu coming on is a more likely cause, or another ingredient in a blend, so check the full label. The dizziness and weakness in the poisoning case above came from raw elder, not from a prepared product.

Can you take elderberry every day?

Most of the research is short. The trials ran for days or a couple of weeks, around a cold, flu season or a long flight, so that's where the safety evidence is strongest. The 2021 review also looked for signs that elderberry overstimulates the immune system and found no reason for concern in healthy people, but no trial has followed people taking it daily for months. If you plan to take it every day through the winter, follow your label and mention it at your next checkup if you have a health condition or take prescription medication. Our guide to how much elderberry to take per day covers amounts by form.

Elderberry for kids

Ask your pediatrician before giving elderberry to a child, and use a product made for children, following its label. Never give honey to a baby under 12 months: many elderberry syrups are made with honey, which the CDC warns can cause infant botulism.

How to take elderberry safely

• Buy a prepared product, a syrup, gummy, capsule or tincture made from processed berries, rather than using raw berries.
• If you make syrup at home, use only ripe berries, take off every stem, and cook them thoroughly. Never juice or blend raw elderberries.
• Only pick wild elderberries if you're certain of the plant, and even then, never eat them raw.
• Stay within the label, and don't stack several elderberry products at once.
• Stop and check with your doctor if you get stomach upset, a rash or any other reaction.

Our Elderberry Soothe and Defend tincture

Our Elderberry Soothe and Defend tincture follows the traditional recipe, built on whole elderberries rather than concentrate, with mullein leaf, nettle leaf, ginger root, cinnamon bark, whole cloves and sweet orange peel. It's made with vegetable glycerin, so it's alcohol-free with no added sugar. The amount is simple: one dropper a day with a meal, for adults, and the label says it isn't intended for children. It's prepared slowly by hand in small batches in Holmes County, Ohio, and sits in our Daily Defense range. For more on what elderberry is and what the research shows, see our elderberry guide.

Frequently asked questions

Who should not take elderberry?

Check with your doctor first if you're pregnant or breastfeeding, have an autoimmune condition, take immune-suppressing, diabetes, diuretic or laxative medication, or want to give it to a child. And nobody should eat raw or unripe elderberries.

Is elderberry safe to take every day?

For most healthy adults, prepared elderberry is well tolerated, though the research covers short courses better than months of daily use. Follow your label and tell your doctor if you have a health condition or take prescription medication.

Can elderberry upset your stomach?

It can, though it isn't common with prepared products. Digestive upset is an infrequent side effect, and elderberry has a mild laxative effect. Follow your label, which for many products, ours included, means taking it with a meal. Raw or unripe elderberries are a different matter: they can cause nausea, vomiting and severe diarrhea.

Can you eat raw elderberries?

No. Raw or unripe elderberries, and the leaves and stems, can cause nausea, vomiting and diarrhea. Cook berries thoroughly or use a prepared product.

Can you take elderberry while pregnant?

Little is known about elderberry's safety in pregnancy or while breastfeeding, and Memorial Sloan Kettering advises avoiding it then, so talk to your doctor or midwife before taking it.

Can you be allergic to elderberry?

Yes, though it's rare. Memorial Sloan Kettering lists allergic reactions as an infrequent side effect. Stop taking it and get medical help if you notice a rash, itching, swelling of the face or lips, or trouble breathing.

Can you take elderberry with echinacea?

For most healthy adults, yes. Both are a question for your doctor if you have an autoimmune condition or take medication that affects the immune system. Our elderberry vs echinacea guide compares the two.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. This article is general information and not medical advice. Talk to your healthcare provider before starting any supplement, particularly if you are pregnant or nursing, take prescription medication, have an autoimmune condition, or are considering it for a child.