Elderberry

Antiviral activity (in vitro). Elderberry extracts and specific polyphenols (especially anthocyanins such as cyanidin glycosides) have been shown in laboratory studies to bind viral surface proteins, inhibit hemagglutination/viral entry and reduce replication of influenza and other respiratory viruses in cell culture. This provides a plausible antiviral mechanism. BioMed Central ScienceDirect

Immunomodulation / anti-inflammatory effects. Elderberry contains flavonoids and anthocyanins that can modulate cytokine production and have antioxidant/anti-inflammatory effects in lab and ex-vivo studies. Some studies show increases in certain cytokines; others show reductions — suggesting elderberry can modulate immune responses rather than only “boost” them. BioMed Central ScienceDirect

Clinical plausibility. Because many colds are caused by viruses and symptoms are driven both by viral replication and immune response, an extract that reduces viral infectivity and favorably modulates inflammation can plausibly shorten symptom duration or reduce severity. That biological plausibility underpins the clinical trials described below. ScienceDirect BioMed Central

Important: products and concentrations vary. If you use elderberry, prefer commercial, standardized extracts/syrups (they’ve been heat-processed to remove toxins and have known polyphenol/anthocyanin content). Follow label instructions and check with your clinician if you have conditions or take medicines that could interact.

Typical trial-based regimens:

• Influenza treatment trials (adult): 15 mL elderberry syrup four times daily for 5 days. (Randomized trial in Norway — symptomatic adults with influenza-like illness; symptom relief occurred ~4 days earlier in the elderberry group vs placebo). Accurate Clinic
• Cold prevention in travellers (adult): 300 mg capsules of standardized elderberry extract were used as follows in a large RCT: priming dose 2 capsules/day (600 mg/day) for 10→2 days before travel, then 3 capsules/day (900 mg/day) from 1 day before travel until 4–5 days after arrival (total trial period ~15–16 days). That trial reported fewer cumulative cold-episode days and lower symptom scores in the elderberry group. (Note: this is prevention context, not acute treatment.) dyna-nutrition.com
• Lozenges / other forms: small pilot lozenge trials and proprietary lozenge products have shown quicker symptom improvement in tiny trials; form matters for dose standardization. Trisha's Elderberries

Practical summary for an adult wanting to treat an acute cold (based on how trials were done — not a clinical guideline):

• Use a commercial standardized elderberry syrup or extract (avoid home raw berry preparations).
• A commonly studied treatment regimen for influenza-like illness is 15 mL orally, four times daily for ~5 days (used in RCTs). Accurate Clinic
• For prevention in high-risk short periods (e.g., travel), trials have used 600–900 mg/day of standardized extract (300 mg capsules × 2–3/day). dyna-nutrition.com

Always: follow the product label and get medical advice if you’re on other medicines or have serious medical conditions.

Systematic reviews / evidence assessments

• Wieland et al., BMC Complementary Medicine and Therapies (systematic review, 2021) — concluded elderberry may reduce duration/severity of colds and influenza but evidence certainty is low to very low because trials are small and have risk of bias; also examined cytokine data and found no clinical evidence of elderberry causing cytokine storms. (Good, recent, balanced review.) BioMed Central

Randomized clinical trials

• Zakay-Rones et al., 2004 — randomized, double-blind trial of oral elderberry syrup vs placebo in adults with influenza A/B: 15 mL four times daily for 5 days; symptoms improved on average ~4 days earlier with elderberry. (J Int Med Res. 2004). Accurate Clinic
• Zakay-Rones et al., 1995 — older outbreak study and in-vitro work showing reduced influenza symptoms and in-vitro inhibition (J Altern Complement Med, 1995). DocDroid
• Tiralongo et al., 2016 (Nutrients) — randomized double-blind placebo-controlled trial in 312 air travellers: standardized elderberry extract capsules (300 mg per capsule; 600 mg/day pre-travel, 900 mg/day during travel) reduced cumulative cold days and symptom scores (prevention context). dyna-nutrition.com
• Smaller pilot RCTs / lozenge studies — several small trials (Kong 2009 pilot, other small trials) report faster symptom improvement but are limited by size/design. The systematic reviews above summarize these. Trisha's Elderberries BioMed Central

In vitro / mechanistic studies

• Roschek et al., 2009 (Phytochemistry) — elderberry flavonoids bind H1N1 and prevent infection in vitro. ScienceDirect
• Krawitz et al., BMC Complementary Medicine 2011 — standardized elderberry liquid extract showed inhibitory activity versus influenza A and B in cell culture and activity against respiratory bacterial pathogens. BioMed Central
• Recent in-vitro work (MDPI/2024 and others) shows elderberry extracts inhibit replication of influenza strains and even show activity in vitro vs SARS-CoV-2 (laboratory results — not clinical evidence). MDPI

Meta-analysis

• Hawkins et al. (2019) and other pooled analyses report a significant reduction in symptom duration/severity across small trials, but reviewers caution about small sample sizes and heterogeneity. ScienceDirect BioMed Central