Compound or practice · Supplement
Echinacea
The classic cold herb — meta-analyses hover near null, with maybe a small prevention/duration effect for some preparations.
- Overall grade
- Grade C
- Last revised
- 1
- graded outcome
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
1 at grade C — 1 graded row
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Cold incidence/durationEvidence grade C
Near-null overall
Smalllow
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Cold incidence/duration (grade C).
The evidence in words
What it is
Echinacea (purpurea/angustifolia) is a flowering-plant extract used to prevent and treat colds.
How it works
Immune-modulating alkamides and polysaccharides; effects vary enormously by species, plant part, and preparation.
What the evidence shows
Cochrane and later meta-analyses land close to null overall, with a possible small reduction in cold incidence/duration for certain standardized preparations. Preparation heterogeneity is the core problem.
How to use it
Standardized extracts at first sign of a cold; benefits, if any, are small.
Safety & interactions
Generally safe; allergy possible (ragweed family); caution in autoimmune disease theoretically.
Bottom line
Mostly disappointing on pooled data, with a slim chance of a small effect from specific preparations. Low-risk, low-yield.
How it is used
As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.
- Standard
- Standardized extract at onset.
Related reading
Entries that share this one's tags or conditions.
- AndrographisOne of the better-evidenced herbs for shortening upper-respiratory infections.Evidence grade B
- ElderberryA popular cold-and-flu berry with small, industry-tinged trials suggesting shorter symptoms — real but overstated.Evidence grade C
- American GinsengDistinct from Asian ginseng — its best data are for glucose control and reducing cold frequency.Evidence grade C
- Andrographis for Common coldEvidence grade B — Severity and durationEvidence grade B
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.