Elderberry (Sambucus nigra) is rich in anthocyanins and polyphenols and has long been used for respiratory health.

This review synthesizes mechanistic and clinical evidence on elderberry as a nutritional adjunct for upper respiratory tract infections (URTI), influenza, the common cold, COVID-19/Long COVID, allergic airway diseases, rhinosinusitis, and pharyngitis, and outlines rational combinations with co-nutrients.

Methods:

We narratively integrated randomized controlled trials, meta-analyses, and in-vitro/in-vivo studies evaluating antiviral, anti-inflammatory, antioxidant, and immunomodulatory actions.

Clinical endpoints included illness duration, symptom severity, medication use, and surrogate markers of inflammation/oxidative stress.

We also appraised complementary roles of quercetin, bromelain, elastin peptides, mulberry leaf polyphenols, vitamin C, vitamin D, and zinc.

Results:

Elderberry exhibits multi-target mechanisms:

• it interferes with viral glycoprotein-host receptor interactions and early replication;
• down-regulates inflammatory signaling (e.g., NF-κB) and cytokines (TNF-α, IL-6);
• scavenges reactive species and activates Nrf2-dependent defenses (GSH, SOD, CAT);
• enhances mucosal immunity (sIgA) and innate cell activity (macrophages, NK cells).

Across RCTs in influenza/URTI, elderberry consistently shortened illness by ~1-2 days and reduced symptom scores, with some trials reporting decreased rescue medication.

Evidence for COVID-19 is indirect - supported by anti-coronavirus in-vitro data and polyphenol-based mechanistic plausibility - but lacks large, definitive clinical trials.

For allergic rhinitis/asthma and rhinosinusitis/pharyngitis, data are mainly mechanistic or small-scale, suggesting potential benefits in nasal congestion, throat pain, cough, and mucosal recovery.

Co-nutrients provide complementary coverage across viral entry/replication, inflammatory amplification, oxidative stress, mucus rheology, and epithelial barrier repair.

Conclusions:

Elderberry is a plausible, evidence-supported adjunct for respiratory infections, with the strongest clinical signal in influenza and URTI.

Early-stage use and deployment in susceptible populations may yield clinically meaningful symptom relief and faster recovery.

Combination protocols with quercetin, bromelain, elastin peptides, mulberry leaf, vitamin C/D, and zinc are mechanistically coherent and may broaden benefits.

Rigorous, adequately powered trials are still needed for COVID-19 and allergic/ENT indications.

Elderberry should complement - rather than replace - standard medical care.