Short answer: No trial has compared them. Echinacea has more research: a Cochrane review of 24 trials found no clear benefit for treating colds and, at best, a small drop in the chance of catching one.1 Elderberry has only a few small trials: one in 312 air travellers found shorter colds,2 but a flu trial in 87 emergency room patients found no benefit.3
| Elderberry | Echinacea | |
|---|---|---|
| Amount of human research | A small number of studies on colds and flu4 | Many studies on colds; 24 trials with 4,631 people in one Cochrane review51 |
| Preventing colds | 17 vs 12 colds in air travellers, not a significant difference2 | No single prevention trial significant; pooled results suggest 10% to 20% fewer colds1 |
| Treating colds | Fewer cold days and milder symptoms in air travellers2 | Only 1 of 7 treatment trials found shorter colds1 |
| Flu | No benefit in 87 emergency room patients with confirmed flu3 | Not covered by the Cochrane review |
| Safety | Raw or unripe berries, leaves and stems contain cyanide-producing substances; cooking removes them4 | Likely safe short term for most adults; allergic reactions can be severe; stomach upset most common5 |
In 312 economy passengers flying from Australia, an elderberry extract did not significantly lower the number of colds, but colds in the elderberry group lasted fewer days in total (57 vs 117) and had lower symptom scores.2 A 2019 meta-analysis pooled trials with 180 people in all and reported a large drop in upper respiratory symptoms.6
A later, larger flu trial disagreed. In 87 people with confirmed flu seen in emergency rooms, elderberry extract did not shorten symptoms versus placebo (5.3 vs 4.9 days to mild symptoms). The lead author notes he had explored a patent on combining elderberry with oseltamivir.3 NIH calls the evidence preliminary, and the FDA and FTC have acted against companies claiming elderberry treats COVID-19.4
The 2014 Cochrane review included 24 double-blind trials of many different echinacea products. For treating colds, only 1 of 7 trials showed shorter colds. For prevention, no single trial was significant, but pooling them suggested 10% to 20% fewer colds, of questionable importance.1 A 2019 meta-analysis found 22% fewer respiratory infections and no change in how long they lasted.7 NIH says echinacea may slightly lower the chance of catching a cold and that it is unclear whether it shortens one.5
Neither has strong evidence. Echinacea has more trials, with at most a small preventive effect; elderberry has a few small trials with mixed results. Products vary a lot for both. This is general information, not personal advice. More detail: the Elderberry Extract and Echinacea guides.