Efficacy of a pelargonium sidoides preparation in patients with the common cold: a randomized, double blind, placebo-controlled clinical trial

Explore (NY). 2007 Nov-Dec;3(6):573-84. doi: 10.1016/j.explore.2007.09.004.


Background: The common cold is a viral infection with symptoms such as sneezing, sore throat, and running nose. It is one of the most prevalent illnesses in the world, and although commonly caused by rhinoviruses, antibiotics are often prescribed unnecessarily. Therefore, it is of utmost importance to evaluate alternative treatments such as herbal medications, whose efficacy and safety is proven by pharmacological and clinical studies.

Objective: The aim of the present study was to evaluate the efficacy of a liquid herbal drug preparation from the roots of Pelargonium sidoides compared with placebo in adult patients with the common cold.

Design: The study was designed as a multicenter, prospective, randomized, double blind, parallel group, placebo-controlled phase III clinical trial with an adaptive group-sequential design.

Setting: The study took place in eight outpatient departments affiliated with hospitals.

Patients: One hundred three male and female adult patients with at least two major and one minor or with one major and three minor cold symptoms (maximum symptom score of 40 points), present for 24 to 48 hours, and who gave provision of informed consent were randomized to receive either 30 drops (1.5 mL) of the liquid herbal drug preparation EPs or placebo three times a day.

Intervention: Patients received randomized treatment for a maximum period of 10 days.

Measurements: The primary outcome criterion was the sum of symptom intensity differences (SSID) of the cold intensity score (CIS) from day one to day five. The CIS consists of the following 10 cold symptoms: nasal drainage, sore throat, nasal congestion, sneezing, scratchy throat, hoarseness, cough, headache, muscle aches, and fever.

Results: From baseline to day five, the mean SSID improved by 14.6 +/- 5.3 points in the EPs group compared with 7.6 +/- 7.5 points in the placebo group. This difference was statistically significant (P < .0001). The mean CIS decreased by 10.4 +/- 3.0 points and 5.6 +/- 4.3 points in EPs and placebo-treated patients, respectively. After 10 days, 78.8% versus 31.4% in the EPs versus placebo group were clinically cured (CIS equals zero points or complete resolution of all but a maximum of one cold symptom; P < .0001). The mean duration of inability to work was significantly lower in the EPs treatment group (6.9 +/- 1.8 days) than in the placebo group (8.2 +/- 2.1 days; P = .0003). Treatment outcome (rates of complete recovery or major improvement from disease [integrative medicine outcomes scale]) was assessed better in the EPs treatment group than in the placebo group by both the investigator and the patient on day five (P < .0001). Adverse events occurred in three of 103 patients (2.9%), with two of 52 (3.8%) and one of 51 (2.0%) patients in the EPs and placebo group, respectively. All adverse events were assessed as nonserious. At the end of treatment, all patients (100%) in the active treatment group judged the subjective tolerability of EPs as good or very good.

Conclusions: EPs represents an effective treatment of the common cold. It significantly reduces the severity of symptoms and shortens the duration of the common cold compared with placebo. The herbal drug is well tolerated.

Publication types

  • Controlled Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Anti-Infective Agents / administration & dosage*
  • Common Cold / drug therapy*
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Echinacea*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pelargonium*
  • Phytotherapy*
  • Plant Extracts / administration & dosage*
  • Prospective Studies
  • Research Design
  • Severity of Illness Index
  • Treatment Outcome


  • Anti-Infective Agents
  • EPs 7630
  • Plant Extracts