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Evaluation of Echinacea for the Common Cold

Evaluation of Echinacea in a Human Rhinovirus Challenge

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00032500
Enrollment
Unknown
Registered
2002-03-25
Start date
2001-09-30
Completion date
2004-05-31
Last updated
2006-08-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Common Cold

Keywords

common cold, Echinacea

Brief summary

The purpose of this study is to determine whether three Echinacea preparations with different chemical compositions are effective for prevention or treatment of the common cold.

Detailed description

Echinacea is a widely used herbal remedy for the common cold. Previous clinical trials designed to assess the efficacy of Echinacea for prevention or treatment of the common cold have produced inconsistent results. A variety of different Echinacea products have been used in these clinical trials. Recent studies indicate that different Echinacea preparations have dramatically different phytochemical profiles. The available clinical trial data provide no information about the potential role of the different constituents of Echinacea in common cold prevention or treatment. Our hypothesis is that the variation in reported clinical effectiveness may be due to differences in the phytochemical profile of the Echinacea preparations used. This study will address the following specific aims: 1) Evaluate the effectiveness of chemically defined extracts of E. angustifolia root which contain alkamides, echinacoside or polysaccharidelglycoprotein for common cold prevention or treatment; 2) Assess the correlation between specific Echinacea metabolites in serum and nasal secretions and efficacy for prevention and treatment of colds; and 3) Determine the effect of different Echinacea preparations on the host response to rhinovirus infection.

Interventions

Sponsors

National Center for Complementary and Integrative Health (NCCIH)
Lead SponsorNIH

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE

Eligibility

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026