American ginseng and colds
What 3 graded rows on american ginseng agree on for colds, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the American ginseng page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the American ginseng page, with its PubMed record.
Your question
American ginseng and colds
3 rows · 1,319 peopleSplit. 1 row found an improvement, 1 found no difference and 1 had mixed results.
- CGrade C× 2
- ∅No effect× 1
- Rows
- 3
- Trials
- 3
- At least: a review without a trial count
- People
- 1,319
- Pooled reviews may count some twice
Where they differ
From the rowsThe best-graded row, grade C, is a systematic review of 747 people (2011) and reported mixed results. 1 row is graded No effect, our grade for adequately powered trials that found no effect.
The row that found an improvement ran longer (4 months) than the row that found no difference (3 months).
The row that found no difference is newer (2012) than the row that found an improvement (2005).
1 row with mixed results is left out of this comparison.
The rows
1 improved · 1 no difference · 1 mixed- CGrade CNumber of laboratory-checked colds · Improved
RCT · n 279 · 2005 · Adults aged 18-65 with at least 2 colds in the prior year (Edmonton, Canada; 323 randomised)
400 mg/day (2 x 200 mg) · 4 months
Colds per person 0.68 vs 0.93 with placebo; 10.0% vs 22.8% had two or more colds; total symptom days 10.8 vs 16.5.
Row on the American ginseng page · PubMed 16247099 (opens PubMed)
- ∅No effectAcute respiratory illness days in chronic lymphocytic leukaemia · No difference
RCT · n 293 · 2012 · Adults with early-stage, untreated chronic lymphocytic leukaemia
Not stated in the abstract · About 3 months (January–March)
Respiratory illness days (8.5 vs 6.8) and severe illness days did not differ from placebo, nor did antibiotic use; moderate to severe sore throat was less common and the extract was well tolerated.
Row on the American ginseng page · PubMed 22266154 (opens PubMed)
- CGrade CCold incidence and duration in healthy adults · Mixed
Systematic review · n 747 · 2011 · Healthy adults in 5 trials, all of North American ginseng
Varied by trial (not pooled in the abstract) · 8-16 weeks
Fewer colds overall in one trial (25%); the chance of catching at least one cold was not clearly lower (RR 0.70, 95% CI 0.48-1.02); colds were 6.2 days shorter in two trials.
Row on the American ginseng page · PubMed 19592479 (opens PubMed)