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.


Aghili M. 2009. Makhzan-al-Advieh, Tehran
University of Medical Sciences: Rah-e
Kamal, Tehran, Iran.
Almohawes Z, Alruhaimi H. 2019. Effect of
Lavandula dentata extract on ovalbumininduced asthma in male guinea pigs. Braz
J Biol, 80: 87-96.
Al-Shamlan F, El-Hashim AZ. 2019.
Bradykinin sensitizes the cough reflex via
a B 2 receptor dependent activation of
TRPV1 and TRPA1 channels through
metabolites of cyclooxygenase and 12-
lipoxygenase. Respir Res, 20: 110.
Anushiravani M, Bakhshaee M, Taghipour A,
Mehri MR. 2018. Comparison of the
therapeutic effect of the Persian Medicine
Protocol with the common treatment of
chronic rhinosinusitis: a randomized
clinical trial. Electron Physician, 10:
Beck KR, Thompson III GR, Odermatt A.
2020. Drug-induced endocrine blood
pressure elevation. Pharmacol Res, 154:
Cao B, Wang Y, Wen D, Liu W, Wang J, Fan
G, Ruan L, Song B, Cai Y, Wei M, Li X.
2020. A trial of lopinavir–ritonavir in
adults hospitalized with severe Covid-19.
N Engl J Med, 382: 1787-1799.
Chamitava L, Cazzoletti L, Ferrari M, GarciaLarsen V, Jalil A, Degan P, Fois AG,
Zinellu E, Fois SS, Fratta Pasini AM,
Nicolis M, Olivieri M, Corsico A, Bono
R, Pirina P, Zanolin ME. 2020.
Biomarkers of oxidative stress and
inflammation in chronic airway diseases.
Int J Mol Sci, 21: 4339.
Costa RS, Carneiro TC, Cerqueira-Lima AT,
Queiroz NV, Alcântara-Neves NM,
Pontes-de-Carvalho LC, Velozo Eda S,
Oliveira EJ, Figueiredo CA. 2012.
Ocimum gratissimum Linn. and
rosmarinic acid, attenuate eosinophilic
airway inflammation in an experimental
model of respiratory allergy to Blomia
tropicalis. Int Immunopharmacol, 13:
Delgado-Roche L, Mesta F. 2020. Oxidative
stress as key player in severe acute
respiratory syndrome coronavirus (SARSCoV) infection. Arch Med Res, 51: 384-
Ezzoubi Y, Bousta D, Lachkar M, Farah A.
2014. Antioxidant and anti-inflammatory
properties of ethanolic extract of
Lavandula stoechas L. from Taounate
region in Morocco. Int J Phytopharm, 5:
Ferner RE, Aronson JK. 2020. Chloroquine
and hydroxychloroquine in covid-19.
BMJ, 369: m1432.
Hajikhani B, Calcagno T, Nasiri MJ, Jamshidi
P, Dadashi M, Goudarzi M, Eshraghi AA,
FACS, Mirsaeidi M. 2020. Olfactory and
gustatory dysfunction in COVID‐19
Qaraaty et al.
AJP, Vol. 13, No. 4, Jul-Aug 2023 410
patients: A meta‐analysis study. Physiol
Rep, 8: e14578.
Hashem-Dabaghian F, Azimi SA, Bahrami M,
Latifi S-A, Enayati A, Qaraaty M. 2022.
Effect of Lavender (Lavandula
angustifolia L.) syrup on olfactory
dysfunction in COVID-19 infection: A
pilot controlled clinical trial. Avicenna J
Phytomed, 12: 1-7.
Hawrył A, Hawrył M, Waksmundzka-Hajnos
M. 2019. Liquid chromatography
fingerprint analysis and antioxidant
activity of selected lavender species with
chemometric calculations. PloS One, 14:
Huang C, Wang Y, Li X, Ren L, Zhao J, Hu
Y, Zhang L, Fan G, Xu J, Gu X, Cheng Z.
2020. Clinical features of patients
infected with 2019 novel coronavirus in
Wuhan, China. The lancet, 395: 497-506.
Kähler C, Derezinski T, Bocian-Sobkowska J,
Keckeis A, Zacke G. 2019. Spicae
aetheroleum in uncomplicated acute
bronchitis: a double-blind, randomised
clinical trial. Wien Med Wochenschr,
169: 137-148.
Kannan S, Ali PSS, Sheeza A, Hemalatha K.
2020. COVID-19 (Novel Coronavirus
2019)-recent trends. Eur Rev Med
Pharmacol Sci, 24: 2006-2011.
Karimi M, Zarei A, Soleymani S,
Jamalimoghadamsiahkali S, Asadi A,
Shati M, Jafari M, Rezadoost H,
Kordafshar G, Naghizadeh A, Mardi R.
2021. Efficacy of Persian medicine herbal
formulations (capsules and decoction)
compared to standard care in patients with
COVID‐19, a multicenter open‐labeled,
randomized, controlled clinical trial.
Phytother Res, 35: 6295-6309.
Kashani MS, Tavirani MR, Talaei SA, Salami
M. 2011. Aqueous extract of lavender
(Lavandula angustifolia) improves the
spatial performance of a rat model of
Alzheimer’s disease. Neurosci Bull, 27:
Komaravelli N, Casola A. 2014. Respiratory
viral infections and subversion of cellular
antioxidant defenses. J
Pharmacogenomics Pharmacoproteomics,
5: 1000141.
Liang Z, Wu L, Deng X, Liang Q, Xu Y, Deng
R, Lv L, Ji M, Hao Z, He J. 2020. The
antioxidant rosmarinic acid ameliorates
oxidative lung damage in experimental
allergic asthma via modulation of
NADPH oxidases and antioxidant
enzymes. Inflammation, 43: 1902-1912.
Liang Z, Xu Y, Wen X, Nie H, Hu T, Yang X,
Chu X, Yang J, Deng X, He J. 2016.
Rosmarinic acid attenuates airway
inflammation and hyperresponsiveness in
a murine model of asthma. Molecules, 21:
Mahmoudpour SH, Leusink M, Putten Lvd,
Terreehorst I, Asselbergs FW, De Boer A,
Maitland-Van Der Zee AH. 2013.
Pharmacogenetics of ACE inhibitorinduced angioedema and cough: a
systematic review and meta-analysis.
Pharmacogenomics, 14: 249-260.
Naghizadeh A, Salamat M, Hamzeian D,
Akbari S, Rezaeizadeh H, Vaghasloo
MA, Karbalaei R, Mirzaie M, Karimi M,
Jafari M. 2021. IrGO: Iranian traditional
medicine General Ontology and
knowledge base. J Biomed Semantics, 12:
Nasiri MJ, Haddadi S, Tahvildari A, Farsi Y,
Arbabi M, Hasanzadeh S, Jamshidi P,
Murthi M, Mirsaeidi M. 2020. COVID-19
clinical characteristics, and sex-specific
risk of mortality: systematic review and
meta-analysis. Front Med (Lausanne), 7:
Rahmanzade R, Rahmanzadeh R, Hashemian
SM, Tabarsi P. 2020. Iran's approach to
COVID-19: evolving treatment protocols
and ongoing clinical trials. Front Public
Health, 8: 551889.
Shah SJ, Barish PN, Prasad PA, Kistler A,
Neff N, Kamm J, Li LM, Chiu CY, Babik
JM, Fang MC, Abe-Jones Y, Alipanah N,
Alvarez FN, Botvinnik OB, Castaneda G,
Dadasovich RM, Davis J, Deng X, DeRisi
JL, Detweiler AM, Federman S,
Haliburton J, Hao S, Kerkhoff AD,
Kumar GR, Malcolm KB, Mann SA,
Martinez S, Mary RK, Mick E,
Mwakibete L, Najafi N, Peluso MJ,
Phelps M, Pisco AO, Ratnasiri K, Rubio
LA, Sellas A, Sherwood KD, Sheu J,
Spottiswoode N, Tan M, Yu G,
Kangelaris KN, Langelier C. 2020.
Clinical features, diagnostics, and
outcomes of patients presenting with
acute respiratory illness: A retrospective
cohort study of patients with and without
COVID-19. EClinicalMedicine, 27:
Lavender syrup impact in COVID-19 patients
AJP, Vol. 13, No. 4, Jul-Aug 2023 411
Sies H. 2015. Oxidative stress: a concept in
redox biology and medicine. Redox Biol,
4: 180-183.
Tabata S, Imai K, Kawano S, Ikeda M,
Kodama T, Miyoshi K, Obinata H,
Mimura S, Kodera T, Kitagaki M, Sato
M, Suzuki S, Ito T, Uwabe Y, Tamura K.
2020. Clinical characteristics of COVID19 in 104 people with SARS-CoV-2
infection on the Diamond Princess cruise
ship: a retrospective analysis. Lancet
Infect Dis, 20: 1043-1050.
Tavakoli A, Vardanjani HM, Namjouyan F,
Cramer H, Pasalar M. 2022. Efficacy of
Persian barley water on clinical outcomes
of hospitalized moderate-severity
COVID-19 patients: a single-blind, addon therapy, randomized controlled clinical
trial. Eur Rev Med Pharmacol Sci, 26:
Taylor–Clark TE. 2015. Oxidative stress as
activators of sensory nerves for cough.
Pulm Pharmacol Ther, 35: 94-99.
Xia S, Zhang Y, Wang Y, Wang H, Yang Y,
Gao GF, Tan W, Wu G, Xu M, Lou Z,
Huang W. 2021. Safety and
immunogenicity of an inactivated SARSCoV-2 vaccine, BBIBP-CorV: a
randomised, double-blind, placebocontrolled, phase 1/2 trial. Lancet Infect
Dis, 21: 39-51.
Yang Y. 2020. Use of herbal drugs to treat
COVID-19 should be with caution. The
Lancet, 395: 1689-1690