Modern extract with conflicting evidence for colds and flu. The 2020 RCT contradicts earlier positive studies, making this one to approach with caution despite popular use.
Traditions: European herbalism, German phytotherapy
Elderflower approved as diaphoretic for fever/chills and expectorant for upper respiratory inflammation. Based on pharmacopoeial descriptions and traditional systems, though no controlled clinical data available.
Positive monograph for elderflower for colds.
Elderflower approved for traditional use: relief of early symptoms of common cold.
Elderberry FRUIT could NOT establish traditional use monograph due to insufficient data on traditional use with specified posology and strength.
Evidence quality is uncertain with conflicting RCT results. Earlier studies from 1995, 2004, and 2016 showed 2-4 day reduction in cold/flu duration with 50% symptom reduction. However, the most recent 2020 RCT (Macknin, 87 participants) using identical dosing found NO benefit - and post-hoc analysis suggested elderberry alone performed worse than placebo. Meta-analysis shows large effect size (1.717) but this was before the negative 2020 study. Critical insight: traditional use evidence supports elderflower, not elderberry fruit. Modern research on fruit extracts represents a departure from traditional use.
87 patients (ages 5+): 15 ml syrup 2-4x/day for 5 days showed NO benefit. Time to symptom alleviation: 5.3 days (elderberry) vs 4.9 days (placebo), p=0.57. Post-hoc: elderberry alone 7.3 days vs placebo alone 5.1 days (p=0.02) - significantly worse.
312 air travelers: 600-900 mg daily standardized extract (15% anthocyanins = 90-135 mg/day) for 15-16 days reduced cold duration by ~2 days (4.75 vs 6.88 days, p=0.02) and symptom severity 50% (247 vs 583, p=0.05)
60 patients (ages 18-54): 15 ml elderberry syrup 4x/day for 5 days - symptoms relieved 4 days earlier than placebo, significantly less rescue medication use
180 participants (89 elderberry, 91 control): Large effect size (1.717) for substantial reduction in upper respiratory symptoms. However, this preceded the 2020 negative RCT.
5 studies, 936 adults: Most effective within 48 hours of symptom onset, 50% symptom reduction within 2-4 days. Effective for fever, headache, nasal congestion. Unclear for cough relief.
Prevention protocol: 600 mg daily for 10 days before exposure, 900 mg daily during exposure. Treatment: 900 mg daily for 5 days. Standardization critical - 3 of 9 products failed quality testing.
Used in multiple trials with mixed results. Positive in 2004 (Zakay-Rones), negative in 2020 (Macknin) using same dosing. Product variability may explain conflict. Duration: 5 days for treatment.
Traditional preparation uses FLOWER, not fruit. WHO-approved for diaphoretic/expectorant effects. Modern clinical research focuses on fruit extracts, which is a departure from traditional use.
Elderberry sits in an uncomfortable position: popular use backed by some positive studies, but contradicted by the most recent rigorous trial. This isn’t just “more research needed” - this is conflicting evidence where the newest data directly challenges earlier findings.
The conflict:
What worked in earlier trials:
Mechanism (partially understood): Primary compounds are cyanidin-3-glucoside and cyanidin-3-sambubioside. Bioavailability is extremely low (<0.5% urinary excretion) with short half-life (1.74-2.57 hours) [9][10]. How clinical effects occur with such low absorption is unclear - possibilities include metabolite activity, gut-level immune effects, or colonic bacterial metabolism to phenolic acids. Elderberry shows 19x higher absorption than blueberry and 6.2x higher than blackcurrant, though absolute bioavailability remains under 1% [10][11].
Critical insight on traditional use: The WHO, German Commission E, and EMA all approve elderFLOWER for traditional use (diaphoretic, expectorant, colds). However, EMA 2014 explicitly stated elderberry FRUIT “could NOT be established” for traditional use monograph due to insufficient historical data [14][15]. Modern research on fruit extracts represents a departure from traditional use, not a continuation of it. When traditional evidence and modern research focus on different plant parts, that’s a red flag.
The disconnect is stark: Traditional European medicine used elderflower, modern supplements use elderberry fruit. These are not the same thing.
Elderflower (Flos) - Well documented:
Elderberry fruit (Fructus) - Insufficient documentation:
The implication: You cannot claim traditional use status for elderberry fruit products. The traditional evidence base supports flower, not fruit. This matters because when tradition says “use the flower” and modern research says “use the fruit,” you’re not following time-tested wisdom - you’re trying something relatively new.
Traditional warnings (still relevant): Raw bark, roots, leaves, and unripe berries contain sambunigrin (cyanogenic glycoside) - risk of cyanide poisoning. Traditional practice of cooking elderberries before use aligns with modern understanding that processing removes toxins [15].
Given the conflicting evidence, approach this cautiously. The most recent study found no benefit and possible harm when used alone.
Standardized capsules (best evidence for prevention):
This protocol showed 2-day shorter colds and 50% less severe symptoms in 312 air travelers [5].
Critical quality requirement: Verify 15-22% anthocyanin standardization. HPLC testing preferred. Three of nine products failed quality testing in 2015 study [8].
Elderberry syrup (mixed evidence):
This exact dosing worked in 2004 (symptom relief 4 days earlier) [6] but showed NO benefit in 2020 [1]. Product variability may explain the conflict - verify anthocyanin content.
Elderflower tea (traditional, not studied):
Dried elderflowers as hot infusion. Traditional use for inducing sweating during fever, expectorant for respiratory mucus. Precise dosing not documented in clinical literature. This is what traditional use actually supports, not the fruit extracts.
Week 1 (if treating active infection):
Prevention approach (before/during high-risk exposure):
Critical reality check: Multiple daily doses needed due to short half-life (1.74-2.57 hours). Once-daily dosing likely insufficient. Positive trials used 4x/day for adults, not convenient once-daily dosing.
Rapid review found 50% symptom reduction within 2-4 days in positive studies [3]. But remember: most recent study found none of this.
Baseline (before trying):
During prevention trial:
During treatment trial:
What you’re looking for: Shorter illness (2-4 days less in positive trials vs none in 2020 trial). Less severe symptoms (50% reduction in positive trials vs no change in 2020). Faster fever resolution. Less need for symptom relief medications.
RED FLAGS - Stop immediately:
What they might report (based on positive trials): “I got through flu season with one cold instead of three,” “My cold was gone in 3 days instead of the usual week.”
NEVER consume:
The standardization crisis: Vlachojannis 2015 analyzed 9 elderberry/chokeberry products with HPLC. Finding: three products were “inappropriate for clinical use” due to insufficient anthocyanin content [8]. This is a 33% failure rate among commercial products.
What to look for:
Why it matters: Positive trials used products standardized to 15% anthocyanins delivering 90-135 mg/day [5][8]. If your product doesn’t contain this, you’re not using what was studied. The 2020 negative study may reflect product variability rather than elderberry ineffectiveness - or vice versa.
Form considerations:
Red flags - Avoid:
This is a use-with-caution herb with genuinely conflicting evidence. Not “preliminary positive results” - actual head-to-head conflict where recent rigorous trial contradicts earlier positive findings.
The case for trying it: Three positive RCTs (1995, 2004, 2016) with 60-312 participants showed consistent 2-4 day reduction in cold/flu duration and 50% symptom reduction [2][5][6][7]. Meta-analysis effect size of 1.717 [4]. Safer adverse event profile than Tamiflu [2]. Prevention protocol in air travelers showed clear benefit [5].
The case against: Most recent RCT (2020, 87 participants) using identical dosing found zero benefit, with post-hoc analysis suggesting possible harm (elderberry alone 7.3 days vs placebo 5.1 days) [1]. Traditional evidence supports elderflower, not fruit - modern use represents departure from tradition [14][15]. Extremely low bioavailability (<0.5%) raises mechanism questions [9][10].
When it might work (if it works): Prevention during high-risk periods (travel, flu season start) using 10-day priming at 600 mg then 900 mg during exposure. Treatment within 48 hours of symptom onset using 900 mg daily or 15 ml syrup 4x/day for 5 days. You notice shorter illness duration (2-4 days less), milder symptoms (50% reduction), less need for OTC medications.
When to skip it: If you’re pregnant/nursing (no safety data), diabetic without close monitoring (hypoglycemia risk), rarely get sick (can’t detect benefit), need immediate relief (slow onset), or uncomfortable with conflicting evidence.
Safety profile: Short-term use (5-16 days) appears safe in non-pregnant adults. No serious adverse events across trials. Common effects: dry mouth (5.7%), constipation (4.6%), rash (4.6%) - not significantly different from placebo [1]. Long-term use beyond 2-3 weeks lacks safety data. Product quality varies - three of nine failed standardization testing [8].
If trying: Start within 48 hours of symptom onset. Use standardized product with verified 15-22% anthocyanins (90-135 mg/day). Multiple daily doses needed (4x/day for adults), not once-daily. Limit to 5 days treatment or 15-16 days prevention. Track duration and severity against your baseline pattern. If no benefit by day 5, discontinue. Consider that the most recent evidence found no benefit - you may be a non-responder or the effect may be product-dependent.
Duration: 5 days for active infection (treatment), 15-16 days for prevention (before/during high-risk exposure). Most effective within 48 hours of symptom onset. Long-term use beyond 2-3 weeks lacks safety data.
What to notice:
Start within 48 hours of symptom onset for best chance of benefit. For prevention during travel or high-risk exposure: 10-day priming phase at 600 mg (90 mg anthocyanins), then 900 mg (135 mg anthocyanins) during exposure. Critical reality: the most recent study found no benefit and possibly harm when used alone. Product quality varies significantly - verify standardization. Very low bioavailability (<0.5%) with short half-life (1.74-2.57 hours) means multiple daily doses needed, not once-daily dosing. What you're tracking: did you get sick less often or recover faster than usual? Compare to your normal pattern.
Generally considered: caution
Contraindications:
Pregnancy/Nursing: Contraindicated due to lack of safety data (precautionary, not evidence of harm). No animal or human studies available.
Short-term use (5-16 days) in non-pregnant adults appears safe. No serious adverse events across clinical trials. Adverse events in Macknin 2020: dry mouth (5.7%), constipation (4.6%), rash (4.6%), bad taste (3.4%) - not significantly different from placebo. Diabetes medication interaction possible (theoretical hypoglycemia risk based on in vitro data - monitor blood glucose if diabetic). Rare allergic reactions documented. Cooked/processed berries safe - do NOT use raw plant parts. Product quality varies: 3 of 9 products failed standardization testing. No evidence of harmful immune overstimulation. Safer adverse event profile than oseltamivir (Tamiflu) per systematic review. Long-term use beyond 2-3 weeks lacks safety data.