Walk into any pharmacy during winter and you’ll find elderberry syrups, lozenges, and capsules prominently displayed. The marketing promises are enticing: natural immune support, cold and flu relief, traditional remedy backed by science. But how much of this holds up under scrutiny?

Elderberry (Sambucus) is a deciduous shrub belonging to the Adoxaceae family (formerly classified under honeysuckle). The berries, flowers, and other parts have been used medicinally for centuries across Europe and North America. The most commonly used species is Sambucus nigra (European elder or black elderberry), though several other species exist.

What makes elderberry interesting to researchers is its phytochemical profile. The berries contain anthocyanins (the pigments responsible for their dark purple colour), flavonoids like quercetin and rutin, and various polyphenols 1. These compounds show antioxidant and anti-inflammatory activity in laboratory settings. The question, as always, is whether this translates to meaningful clinical benefits.

Back in 400 BC, Hippocrates reportedly called the elder tree his “medicine chest” due to its wide range of applications. Before antibiotics existed, elderberry preparations were a staple in European pharmacopoeias. Today, it’s primarily marketed as an immune support supplement, particularly for colds and influenza. Let’s look at what the research actually shows.

1. Elderberry may shorten upper respiratory infections

This is the claim you’ll see most often, and it’s also where the most human research exists. Upper respiratory tract infections encompass the common cold, influenza, and similar illnesses affecting the nose, sinuses, pharynx, and larynx. Symptoms typically include cough, sore throat, runny nose, nasal congestion, headache, and sometimes fever.

The most cited evidence comes from a 2019 meta-analysis that pooled data from four randomised controlled trials involving 180 patients with upper respiratory symptoms 2. The analysis found that elderberry supplementation significantly reduced both the duration and severity of symptoms.

Interestingly, the researchers found that the magnitude of improvement was more pronounced for influenza than for the common cold. Vaccination status didn’t appear to influence the results, suggesting elderberry might offer benefits regardless of whether someone has had a flu jab.

My take: The meta-analysis is encouraging, but 180 patients across four studies is quite small. The effect seems real, but I wouldn’t expect miracles. If you’re considering elderberry for winter wellness, think of it as one tool among many rather than a magic bullet. Vitamin C and zinc have more extensive research for similar purposes.

2. Topical elderberry gel may help knee osteoarthritis

Osteoarthritis is the most common form of arthritis, characterised by cartilage breakdown and joint degeneration. It’s a leading cause of disability worldwide, particularly affecting the knees, hips, and hands. Risk factors include age, obesity, previous joint injury, genetics, and metabolic conditions.

A 2016 randomised, double-blind trial examined topical elderberry gel (made from Sambucus ebulus leaves, a different species known as dwarf elder) in 79 patients with knee osteoarthritis 3. The comparison was against diclofenac, a non-steroidal anti-inflammatory drug commonly used topically for joint pain.

After four weeks, the elderberry gel group showed greater improvements in WOMAC pain scores, total WOMAC scores, and visual analogue scale (VAS) measurements than the diclofenac group. This is a surprising finding, given that diclofenac is a proven medication.

The catch: This was a single study with 79 participants, and it used a different elderberry species (Sambucus ebulus rather than Sambucus nigra). The results are intriguing but need replication. If you’re dealing with osteoarthritis, I’d suggest looking at the broader evidence for supplements like glucosamine, curcumin, and collagen while keeping topical elderberry on your radar as an interesting possibility.

3. Elderberry extract may aid paederus dermatitis healing

Paederus dermatitis is an acute skin reaction caused by crushing paederus beetles (also called rove beetles or Nairobi flies) on the skin. When squashed, these insects release paederin, a toxic compound that causes burning, blistering, and pustules. The condition can be mistaken for herpes or bacterial infections.

A randomised, double-blind trial tested a 5% elderberry alcohol solution combined with hydrocortisone ointment against 70% ethanol with hydrocortisone in 62 patients 4. The elderberry group showed faster resolution of burning, pain, inflammation, and infection. About 94% of the elderberry group had complete resolution within 48 hours, compared to 65% in the control group.

Worth noting: This is admittedly a niche application. Most readers probably aren’t dealing with beetle-induced dermatitis. But it does demonstrate that elderberry has genuine biological activity beyond the cold and flu claims. The anti-inflammatory effects seen in laboratory studies appear to translate to at least some clinical scenarios.

4. Limited evidence for cardiovascular protection

Cardiovascular disease remains the leading cause of death globally. Modifiable risk factors include high cholesterol, smoking, hypertension, diabetes, obesity, poor diet, physical inactivity, and excessive alcohol consumption 5. Given that elderberry contains antioxidant compounds, researchers have wondered whether it might offer cardiovascular benefits.

A 12-week double-blind study examined elderberry extract in 52 postmenopausal women, a group at elevated cardiovascular risk 6. The researchers measured inflammation markers, vascular reactivity, and blood lipids. The conclusion was underwhelming: while elderberry appeared safe, there were no significant improvements in any cardiovascular risk markers.

Reality check: This is one study, and absence of evidence isn’t evidence of absence. But it does suggest we shouldn’t expect elderberry to be a cardiovascular panacea. If you’re concerned about heart health, focus on established interventions: diet, exercise, smoking cessation, and medications if prescribed by your doctor.

5. Animal research suggests potential for diabetic bone loss

Osteoporosis is common in people with diabetes, with roughly one-third to two-thirds of diabetic patients experiencing reduced bone strength and about one-third eventually diagnosed with osteoporosis 7.

Animal research using diabetic mice has suggested that elderberry extract might slow bone loss and improve osteoporosis markers 8. The proposed mechanism involves the antioxidant compounds reducing oxidative stress that contributes to bone breakdown in diabetes.

Important caveat: This is animal research only. Mice are not humans, and many promising findings in rodents fail to translate to clinical practice. Without human trials, this remains speculative. Don’t take elderberry supplements expecting them to protect your bones.

6. Minor effects on cholesterol

Cholesterol is essential for cell membrane integrity and hormone production, but elevated levels, particularly of LDL cholesterol, increase cardiovascular risk. Dietary and lifestyle interventions are first-line treatments, with medications reserved for those at higher risk.

A small double-blind study in 34 healthy volunteers examined low-dose elderberry extract over two weeks 9. The researchers found a modest reduction in post-meal lipid levels compared to placebo.

In practice: Two weeks is too short, 34 participants is too few, and “healthy volunteers” may not respond the same as people with actual lipid problems. Consider this preliminary evidence at best. If you have cholesterol concerns, work with your doctor on proven approaches.

Are there side effects of elderberry?

Commercially prepared elderberry extracts, taken at recommended doses for short periods, appear to be well tolerated. Clinical trials haven’t reported significant adverse effects from standardised products.

However, there’s an important distinction between processed products and raw plant material. Unripe berries, uncooked berries, and other plant parts (leaves, bark, roots) contain cyanogenic glycosides and lectins that can cause toxic reactions 10. Symptoms of toxicity include nausea, vomiting, abdominal cramps, diarrhoea, weakness, and in severe cases, dizziness and confusion.

The NHS advises that elderberries must be properly cooked before consumption to neutralise these compounds 11. Never eat raw elderberries picked from hedgerows, and don’t make your own elderberry preparations unless you know exactly what you’re doing.

Some people experience allergic reactions to elderberry. If you develop symptoms such as itching, rash, swelling, difficulty breathing, or anaphylaxis, stop use immediately and seek medical attention.

Safety precautions and contraindications

1. Pregnancy and breastfeeding: The safety of elderberry supplements during pregnancy and lactation hasn’t been established. Without adequate data, most health authorities recommend avoidance.

2. Children: While elderberry syrups are often marketed for children, paediatric safety data is limited. If you’re considering elderberry for a child, discuss it with their healthcare provider first.

3. Liver or kidney impairment: There’s insufficient research on elderberry use in people with compromised organ function. Caution is warranted.

4. Autoimmune conditions: Elderberry may stimulate the immune system, which could theoretically worsen autoimmune diseases like rheumatoid arthritis, lupus, multiple sclerosis, or inflammatory bowel disease. People with these conditions, or those who have received organ transplants and take immunosuppressant medications, should generally avoid elderberry.

5. Drug interactions: Elderberry may interact with several medication classes:

Immunosuppressants (cyclosporine, azathioprine, corticosteroids): Elderberry’s immune-stimulating effects could counteract these drugs
Diabetes medications: Elderberry might lower blood sugar, potentially causing hypoglycaemia when combined with insulin or oral hypoglycaemics
Diuretics: Possible additive effects
Laxatives: Possible additive effects leading to excessive fluid loss
Chemotherapy drugs: Unknown interactions; avoid concurrent use without medical supervision

The bottom line on elderberry

Elderberry isn’t snake oil, but it’s not a wonder supplement either. The evidence for reducing cold and flu duration is the most compelling, though still based on small studies. The osteoarthritis research is intriguing but preliminary. For cardiovascular health and most other claimed benefits, the evidence is weak or absent.

If you want to try elderberry for winter immune support, choose a reputable product with standardised extract, follow dosage instructions, and don’t exceed recommended duration of use. Be especially careful if you have autoimmune conditions, take immunosuppressant medications, or have diabetes.

And perhaps most importantly: elderberry supplements are not a substitute for flu vaccination, hand hygiene, and other evidence-based measures for preventing respiratory infections. Probiotics may also offer some support for immune function and are worth considering as part of a broader wellness approach.