Echinacea

Safety and Efficacy Profile of Echinacea purpurea to Prevent Common Cold Episodes: A Randomized, Double-Blind, Placebo-Controlled Trial

Study: This RCT investigated the safety and efficacy of an alcohol extract of Echinacea purpurea (Echinaforce®) for preventing common cold episodes over 4 months. It involved 755 healthy adults receiving either echinacea (2400 mg daily) or placebo, with nasopharyngeal swabs collected to assess viral infections, including coronaviruses.

Findings: Echinacea reduced the number of cold episodes (149 vs. 188 in placebo) and cumulative episode days (672 vs. 850, p < 0.05). Recurring infections were significantly lower in the echinacea group (65 vs. 100 episodes, p < 0.05). Enveloped virus infections, including coronaviruses (e.g., 229E, HKU1, OC43), were lower in the echinacea group (24 vs. 47, p = 0.0114). No significant difference in adverse events (AEs) between groups, with good tolerability (64% in echinacea vs. 71% in placebo rated tolerability as “good” or “very good”). No evidence of allergic reactions, leucopenia, or autoimmune issues. Echinacea showed a modest preventive effect on colds and enveloped viruses, with a favorable safety profile.

Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4528044/

Echinacea Reduces Antibiotic Usage in Children Through Respiratory Tract Infection Prevention: A Randomized, Blinded, Controlled Clinical Trial

Study: This RCT evaluated Echinacea purpurea extract (1200 mg daily, Echinaforce®) vs. control in 203 children (aged 4–12 years) over 4 months to assess prevention of respiratory tract infections (RTIs) and reduction in antibiotic use. Nasopharyngeal samples were tested for viral infections.

Findings: Echinacea significantly reduced the incidence of RTIs compared to control. Antibiotic usage was lower in the echinacea group, suggesting a preventive effect that reduced the need for antibiotics. A 98.5% reduction in coronavirus concentration in nasal secretions was observed in the echinacea group. Some children developed rashes, potentially due to allergic reactions, indicating caution for pediatric use. Echinacea may reduce RTI incidence and antibiotic use in children, but allergic risks need consideration.

Link: https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-021-00501-5

Echinacea purpurea Therapy for the Treatment of the Common Cold: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Study: This RCT assessed the efficacy of a standardized Echinacea purpurea preparation in reducing symptom severity and duration of the common cold in 128 adults. Participants received echinacea or placebo at the onset of cold symptoms.

Findings: No significant reduction in symptom severity or duration was observed in the echinacea group compared to placebo. This study did not support the use of E. purpurea for treating common cold symptoms, highlighting variability in echinacea efficacy across trials.

Link: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/213126

A Randomized Controlled Trial of the Effect of Fluid Extract of Echinacea purpurea on the Incidence and Severity of Colds and Respiratory Infections

Study: This RCT involved 108 adults with a history of frequent colds (>3 per year) randomized to receive 4 mL of Echinacea purpurea fluid extract or placebo twice daily for 8 weeks. Incidence and severity of colds were assessed via patient-reported symptoms and physical exams.

Findings: Incidence of colds was similar between groups (65% in echinacea vs. 74% in placebo, RR = 0.88, 95% CI 0.60–1.22). Average number of colds per patient was 0.78 (echinacea) vs. 0.93 (placebo, p = 0.33). Median cold duration was 4.5 days (echinacea) vs. 6.5 days (placebo, p = 0.45), suggesting a non-significant trend toward shorter duration. No statistically significant effect on cold incidence or severity, though a trend toward reduced duration was noted.

Link: https://www.amjmed.com/article/S0002-9343(98)00385-8/fulltext

Randomised, Double Blind, Placebo-Controlled Trial of Echinacea Supplementation in Air Travellers

Study: This RCT examined whether a standardized Echinacea purpurea root extract (4.4 mg alkylamides) could prevent respiratory symptoms during long-haul flights. 175 adults traveling from Australia to America, Europe, or Africa were randomized to echinacea or placebo, with symptoms assessed before, during, and after travel.

Findings: Respiratory symptoms increased in both groups during travel, but the echinacea group had borderline significantly lower symptom scores (p = 0.05). Two allergic reactions were reported in the echinacea group, both in participants with a history of mild plant allergies. Echinacea showed a modest reduction in respiratory symptom severity during travel, but benefits may not generalize to other populations (e.g., those with respiratory or immune disorders).

Link: https://www.hindawi.com/journals/ecam/2012/417267/

Echinacea for Preventing and Treating the Common Cold (Cochrane Review)

Study: This systematic review analyzed 24 double-blind RCTs with 4631 participants, comparing various Echinacea preparations (e.g., E. purpurea, E. angustifolia) to placebo for preventing or treating colds. It included 10 prevention trials and 15 treatment trials, with outcomes focused on cold incidence and duration.

Findings: None of the 12 prevention comparisons showed a statistically significant reduction in cold incidence, but an exploratory meta-analysis suggested a small reduction (risk ratio 0.83, 95% CI 0.75–0.92, p < 0.001). Treatment: No consistent evidence that echinacea shortens cold duration compared to placebo. No significant difference in adverse events between echinacea and placebo groups, though a trend toward more dropouts due to AEs in prevention trials was noted.

Echinacea may have a small preventive effect on cold incidence, but evidence for treatment efficacy is weak. Variability in preparations limits conclusions.

Link: https://www.cochrane.org/CD000530/ARI_echinacea-for-preventing-and-treating-the-common-cold

Echinacea angustifolia and Echinacea purpurea Supplementation Combined with Vaginal Hyaluronic Acid to Boost the Remission of Cervical Low-Grade Squamous Intraepithelial Lesions (L-SILs): A Randomized Controlled Trial

Study: This RCT evaluated Echinacea angustifolia and E. purpurea supplementation combined with vaginal hyaluronic acid in 150 women with low-grade squamous intraepithelial lesions (L-SILs) to assess remission rates compared to a control group.

Findings: Echinacea supplementation significantly improved remission rates of L-SILs compared to control. No significant adverse effects were reported, suggesting safety in this context. Echinacea may support remission of cervical L-SILs when combined with hyaluronic acid, potentially due to immunomodulatory effects.

Link: https://www.mdpi.com/1648-9144/58/5/646