title: The effect of a herbal formulation on the incidence and severity of upper respiratory symptoms in healthy volunteers: an open-label, randomised controlled clinical trial.
abstract: BACKGROUND
  Many traditional preparations with varying combinations of herbs have been used for over 1500 years to treat upper respiratory ailments, and reduce their incidence and severity. Link Samahan® is a formulation containing the extract of 14 such medicinal plants.
  
  
  OBJECTIVE
  To test the efficacy of Link Samahan® in reducing the incidence and severity of upper respiratory symptoms in consenting healthy volunteers.
  
  
  METHODS
  MAS Linea Aqua, a factory with over 3000 employees, having its own health care centre with a qualified matron and visiting medical officers.
  
  
  METHODS
  956 healthy volunteers took daily either one sachet of Link Samahan® in hot water (test group,n=465, mean age 29.5 ± 7.7 years, women 418) or only plain tea (control group n=491, mean age 29.7 ± 7.9, women 448), for 84 consecutive days, and recorded the incidence and severity of 15 upper respiratory symptoms daily in a purpose-designed form.
  
  
  RESULTS
  At the end of 84 days, when compared to the control group, the average incidence of symptoms in the test group showed highly significant reductions at p&lt;0.001 for 6 symptoms and at p&lt;0.005 for 3 symptoms,and at p&lt;0.05 for the remaining 6. Reduction of average incidence over time also was highly significant (p&lt;0.001) for 2 symptoms and (p&lt;0.005) for 7, and significant (p&lt;0.05) for 4 symptoms, but only marginal for the balance 2. Severity was significantly reduced (p&lt;0.05) for 7 symptoms, and reduced also for the other 8 according to descriptive analysis, though not significant at the 5% level.
  
  
  CONCLUSIONS
  The results indicate that Link Samahan® taken as one sachet daily significantly reduces average incidence, incidence over time, and severity of 15 upper respiratory symptoms in healthy adults.
authors.affiliation: Emeritus Professor of Physiology, University of Colombo and Registrar, Ceylon Medical College Council, Sri Lanka. si7np5e@gmail.com
authors.forename: C
authors.initials: C
authors.lastname: Goonaratna
authors.forename: M R
authors.initials: MR
authors.lastname: Sooriyarachchi
mesh_terms: D000328:Adult; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*; D010946:Plants, Medicinal; D012141:Respiratory Tract Infections / Q000517:prevention & control*; D012720:Severity of Illness Index; D013188:Sri Lanka; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D004338:Drug Combinations; D010936:Plant Extracts