Lavender (Lavandula angustifolia) syrup as an adjunct to standard care in patients with mild to moderate COVID-19: An open-label, randomized, controlled clinical trial

Document Type : Original Research Article


1 Clinical Research Development Unit (CRDU), Sayad Shirazi Hospital, Department of Persian Medicine, School of Medicine, Golestan University of Medical Sciences, Gorgan, Iran

2 Academic Center for Education Culture and Research, Tehran, Iran

3 Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran

4 Department of Traditional Medicine, Institute for Studies in Medical History, Persian and Complementary Medicine, School of Persian Medicine, Iran University of Medical Sciences, Tehran, Iran

5 Gonbad-E-Kavoos Health center, Golestan University of Medical Sciences, Gonbad-E-Kavoos, Iran

6 H.S.Z.H. Government Unani Medical College, Bhopal (M.P), India

7 Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran

8 Ischemic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran


Objective: The ongoing COVID-19 pandemic has been associated with clinical signs characterized by fever, fatigue and cough. Our study aimed to assess the efficacy of a Persian medicine formulation, lavender syrup, as an add-on to standard care in patients with mild to moderate COVID-19.
Materials and Methods: In this clinical trial which was conducted in Gorgan (Iran), 84 male and female COVID-19 outpatients were randomly allocated to either lavender syrup receiving 9 ml/twice/day for 21 days with standard conventional care or control groups. The primary objectives were to assess the improvement of clinical symptoms, while the secondary objectives were treatment satisfaction and anxiety levels which were evaluated once a week for 3 weeks.
Results: Out of 84 participants, 81 were analyzed (41 in the add-on group). The comparison between groups for cough severity and anosmia showed a higher reduction in the lavender group. The effect size was 0.6 for cough relief. Other symptoms and the Hamilton total score decreased in both groups with no statistically significant differences between the groups. The lavender group showed greater patients’ satisfaction score.
Conclusion: Adjunctive therapy with lavender syrup could reduce cough and improve the quality of life in patients with COVID-19 patients.