Recruiting

Olfactory Training

Sponsor:

Université du Québec à Trois-Rivières

Code:

NCT05384561

Conditions

Hyposmia

COVID-19

Parosmia

Anosmia

SARS-CoV-2 Infection

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Smell training

Study Details

Brief summary:

Olfactory dysfunction is a defining symptom of COVID-19 infection. Studies have demonstrated improved olfaction in patients with post infectious olfactory dysfunction after an olfactory training (OT). The aim of this study is to assess the clinical outcomes of olfactory training (12 weeks) therapy in the treatment of persistent olfactory dysfunctions after COVID-19. Specially, we aim to compare the effectiveness of two different olfactory training (different odors).

A group will train themselves with 4 scents (rose, orange, clove and eucalyptus) and another group with 4 different scents (cheese, coffee, strawberries and lemon). Olfaction sensory evaluation will be performed by using different olfaction tests (Sniffin' Sticks and UPSIT) and complete questionnaires to assess olfactory perception and particularly parosmia and phantosmia.

Conditions

Hyposmia

COVID-19

Parosmia

Anosmia

SARS-CoV-2 Infection

Study ID

NCT05384561

Start date

May 31, 2022

Status verified date

Jul, 2026

Completion date

Sep, 2027

Anticipated

Primary completion date

Sep, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Patient diagnosed positive for COVID-19 with persistent olfactory dysfunction
  • Willing and able to provide written informed consent
  • Understand and read the French language
  • Have an internet connection and a working email address

Exclusion Criteria:

  • Anosmia and hyposmia pre-covid-19
  • Be known chronic rhinosinusitis with or without nasal polyposis
  • Have received radiotherapy or chemotherapy for Head and Neck Tumors
  • Have a diagnosis of Alzheimer's, Parkinson's, multiple sclerosis or any other neurodegenerative disease 5. Have a brain tumor or ENT diagnosis 6. History of naso-sinus surgery; 7. History of traumatic brain injury

Study Design

Enrollment

70 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Chemosensory training group 1

For 12 weeks, morning and evening, smell four odors namely eucalyptol, phenyl ethanol, Orange, and eugenol, for a total of five minutes per session.

experimental: Chemosensory training group 2

For 12 weeks, morning and evening, smell four odors namely coffee aroma, cheese aroma, strawberries, and limon, for a total of five minutes per session.

Interventions

Smell training

For 12 weeks, morning and evening, smell four different odors or four odorless substances for a total of five minutes per session.

Primary outcome measure

  • Changes from baseline in olfactory score on the University of Pennsylvania Identification Test (UPSIT) [ Time Frame: Measurement will be taken at time zero (pre-intervention) and 12 weeks (post-intervention) [ Time Frame: Measurement will be taken at time zero (pre-intervention) and 12 weeks (post-intervention) ]
  • Changes from baseline in olfactory score on the Sniffin's Sticks test [ Time Frame: Measurement will be taken at time zero (pre-intervention) and 12 weeks (post-intervention) ]
  • n-house test for chemosensory dysfunction (TMSC) [ Time Frame: Measurement will be taken at time zero (pre-intervention) and 12 weeks (post-intervention) ]
  • Parosmia and phantosmia assessment test [ Time Frame: Measurement will be taken at time zero (pre-intervention) and 12 weeks (post-intervention) ]
  • The abridged version of the Questionnaire of Olfactory Disorders - Negative Statements (sQOD-NS) [ Time Frame: Measurement will be taken at time zero (pre-intervention) and 12 weeks (post-intervention) ]

Central Contacts and Locations

Central contacts

Johannes A Frasnelli, PhD

18193765011johannes.a.frasnelli@uqtr.ca

Frank Cloutier, PhD

18193765011frank.cloutier@uqtr.ca

Locations

Université du Québec à Trois-Rivières

Recruiting

Trois-Rivières, Quebec, Canada, G8Z 4M3

Contacts

Frank Cloutier, PhD

18193765011frank.cloutier@uqtr.ca

Simon Bérubé, Med Student

simon.berube.1@umontreal.ca

More Information

Sponsor

Université du Québec à Trois-Rivières

Last update posted

Jul 31, 2026

Last verified

Jul, 2026

Keywords

  • Olfactory training
  • Chemosensory impairments
  • Persistent smell impairment

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Université du Québec à Trois-Rivières on 2026-07-31.