Quick summary

Elderberry (Sambucus nigra) is a traditional medicinal plant explored for its potential antiviral, antioxidant, anti-inflammatory, and immunomodulatory properties. Clinical investigations mainly focus on its use for acute respiratory viral infections such as the common cold and influenza, with some studies during the COVID-19 pandemic exploring possible benefits and safety concerns. Evidence suggests elderberry may reduce the duration and severity of respiratory viral symptoms but does not support its use for COVID-19 treatment. Overall, clinical data indicates potential for symptomatic relief with good tolerability, although the quality of evidence remains limited.

What is it

Elderberry refers to the fruit and flowers of the plant Sambucus nigra, a shrub native to Europe and parts of North America. It has been traditionally used in herbal medicine for its purported health-supporting effects, particularly related to respiratory health. Elderberry products include extracts, syrups, capsules, and teas.

Traditional uses

  • Relief of common cold and flu symptoms
  • Support for immune function
  • Reduction of fever and inflammation
  • General antioxidant support

Active compounds

Elderberry contains various bioactive compounds, including:

  • Flavonoids (e.g., quercetin, anthocyanins)
  • Phenolic acids
  • Vitamins (such as vitamin C)
  • Polysaccharides

Potential benefits with evidence levels

  • Reduction of duration and severity of acute respiratory viral infections (e.g., common cold and influenza) — Moderate evidence: Multiple randomized clinical trials involving 936 adults suggest that elderberry mono-herbal preparations taken within 48 hours of symptom onset may reduce symptom duration and severity by approximately 50%. Effects on cough and antibiotic use remain inconsistent. (Wieland et al. 2021, PMID: 33827515)
  • Potential reduction in influenza complications and adverse events compared to oseltamivir — Low evidence: One study indicated that an elderberry-containing product may be associated with a lower risk of influenza complications and adverse events than oseltamivir, though the data quality is limited. (Wieland et al. 2021, PMID: 33827515)
  • Immunomodulatory and anti-inflammatory effects — Preclinical and limited clinical evidence: Elderberry shows antiviral and immunomodulatory properties, including modulation of inflammatory cytokines. There is no conclusive evidence that elderberry overstimulates immune responses or increases the risk of cytokine storm in viral infections such as COVID-19. (Asgary & Pouramini 2022, PMID: 36518861; Wieland et al. 2021, PMID: 33827515; Martin & Richardson 2021, PMID: 34924893)
  • Improvement in quality of life and symptom severity in viral respiratory infections in adults — Preliminary clinical evidence: Some rapid reviews and clinical trials associate elderberry extract with symptom relief in influenza-like illnesses; however, effects on direct viral prevention or treatment of COVID-19 remain unclear. (Harnett et al. 2020, PMID: 32864330)

Side effects

Elderberry extracts are generally well tolerated with a low incidence of adverse events in short-term clinical trials. Reported adverse events are rare, mild, and occur at comparable or lower rates than control groups. No serious adverse events have been consistently reported. (Wieland et al. 2021, PMID: 33827515)

Drug interactions

No specific drug interactions with elderberry have been documented in reviewed clinical studies. However, data remain insufficient to conclusively rule out interactions, particularly with immunomodulatory or anticoagulant medications. Caution is advised when combining elderberry with other drugs affecting the immune system or blood clotting.

Who should avoid it

  • Pregnant or breastfeeding women — due to insufficient safety data, use is not recommended without medical supervision.
  • Individuals with autoimmune diseases — caution is advised given the immunomodulatory potential, though evidence of harm is lacking.
  • People with known allergies to elderberry or related plants.

Evidence limitations

  • Most clinical evidence comes from small to moderate-sized trials with variability in elderberry preparations, dosing, and study design.
  • Lack of large-scale, high-quality randomized controlled trials, particularly in populations at higher risk or with COVID-19.
  • Uncertainty remains regarding long-term safety, immune modulation effects, and pharmaceutical interactions.
  • Limited evidence in pediatric, pregnant, and breastfeeding populations.
  • Many studies focus on symptom relief rather than prevention or cure of infections.

References

Last reviewed

June 2024

Informational disclaimer: This article is for informational purposes only and is not intended as medical advice. Always consult a healthcare professional before using herbal products, especially if you are pregnant, nursing, have a medical condition, or are taking other medications.