Olfactory Dysfunction

12

Review clinical trials related to Olfactory Dysfunction. Use filters to narrow results by trial status, phase, treatment, biological sex and sponsor.

Condition / disease
Location
Status: Recruiting

Slow-SPEED UK: A Double-Blind Randomised Feasibility Trial

Slow-SPEED UK is an 18-month randomised, double-blind feasibility trial evaluating the delivery, adherence, and acceptability of a digitally supported physical activity programme in community-dwelling adults aged 40 and over with objectively confirmed hyposmia (reduced sense of smell) and low baseline physical activity. Participants are randomly assigned 1:1 to either a full-dose activity-support programme (targeting a 100% increase in daily step count) or a very low-dose active control (targeting a 10% increase). Both arms are delivered via a smartphone application linked to a wearable activity monitor (Fitbit Charge 6), with personalised weekly goals expressed as relative percentages to maintain blinding. The study is not designed to test clinical efficacy.

Participants needed: 110
Trial details
Age: 40-100Biological sex: AllType: InterventionalSponsor: Queen Mary University of LondonUpdated: Jun 29, 2026Locations: 1
Eligibility criteria

Age ≥ 40 years [+6]

Clinical diagnosis of PD, dementia, or other neurodegenerative conditions [+8]

Status: Not yet recruiting

Olfactory Dysfunction in Aging Adults

This prospective longitudinal cohort study will enroll adults aged 50 years and older to characterize olfactory dysfunction in aging. Participants will undergo comprehensive olfactory testing, cognitive assessment, biomarker collection, and imaging to identify clinically relevant phenotypes based on anatomic site of dysfunction. The study will also evaluate the impact of olfactory dysfunction on quality of life and identify baseline factors associated with changes in olfactory function over time.

Participants needed: 500
Trial details
Age: 50+Biological sex: AllType: ObservationalSponsor: Medical University of South CarolinaUpdated: Jun 22, 2026Locations: 1
Eligibility criteria

Age: 50 years or older [+2]

Status: Recruiting

Dysfunction of Olfaction After COVID-19 Infection: Morphological and Histomolecular Investigation

Investigation of the mechanisms of persistent SARS-CoV-2 associated olfactory dysfunction (OD) in patients with well-documented olfactory function. The investigators plan to collect olfactory cleft biopsies and cytobrushes in COVID-19 patients and controls.

Participants needed: 240
Trial details
Age: 18-70Biological sex: AllType: InterventionalSponsor: Universitaire Ziekenhuizen KU LeuvenUpdated: May 6, 2026Locations: 7
Eligibility criteria

Olfactory Dysfunction group: Presence of evident OD (Parosmia, Threshold-Discrim... [+1]

Presence of concomitant nasal mucosal pathology that might affect olfactory func... [+2]

Status: Not yet recruiting

In Vivo Imaging of the Olfactory Epithelium Using Confocal Laser Endomicroscopy

This research is being done to better characterize the part of the nose that helps us smell. Currently, the only ways to study smell loss mostly rely on how people report it, rather than being able to see the underlying structures directly. In this study, we will use a special microscope (Confocal Laser Endomicroscopy (CLE)), originally developed for brain tissue, to look at the part of the nose that helps to detects smell. We hope to identify the tiny structures in that area and see how they might be different in people who have smell loss compared to those who do not.

Participants needed: 36
Trial details
Age: 18+Biological sex: AllType: ObservationalSponsor: Dartmouth-Hitchcock Medical CenterUpdated: Apr 23, 2026Locations: 1
Eligibility criteria

Adults aged ≥18 years [+3]

Known allergy or hypersensitivity to fluorescein [+4]

Status: Recruiting

Scents of Progress: Leveraging a Novel Device for Olfactory Training in Older Adults

The goal of this clinical trial is to learn if ScentCare, a novel olfactory training device and accompanying companion web-based application, will lead to improved olfactory and well-being outcomes in elderly patients with Olfactory Dysfunction (OD). The main question it aims to answer is: \- What effect does the olfactory training device (ScentCare) and accompanying companion web-based application have on olfaction? Researchers will compare ScentCare to solving Sudoku puzzles to see the effects of olfactory training using this novel device on olfaction. Previous studies have used Sudoku puzzles when studying the effect of smell training. Since smell training is thought to work by stimulating and engaging higher order cognition, Sudoku is a suitable activity for participants in the control group since it serves as a correlate with similar degree of stimulation. Participants will: * Use ScentCare (intervention) or solve Sudoku puzzles (control) twice daily for 3 months. * Visit the clinic twice, once upon enrollment and once three months later. * Complete a formal smell test using Sniffin' Sticks smell test at the beginning of the study and again at the end of the study (3 months) during the initial and follow up visit. * Complete questionnaires at the beginning of the study and again at the end of the study (3 months) during the initial and follow up visit.

Participants needed: 60
Trial details
Age: 60+Biological sex: AllType: InterventionalSponsor: Johns Hopkins UniversityUpdated: Apr 13, 2026Locations: 1
Eligibility criteria

Adults 60 years of age or older. [+3]

Patients who are sensitive to any of the scents used in the study. [+1]

Status: Not yet recruiting

PANDORA: Evaluation of Platelet-rich Plasma in Non-tumoural Odour Disorders: a Descriptive Pilot Study.

This is a prospective, single-center, single-arm, non-comparative descriptive pilot study evaluating autologous platelet-rich plasma (PRP) injections in adults with persistent (\>6 months) non-tumoural olfactory dysfunction, either age-related degenerative olfactory dysfunction (DOD) or post-traumatic olfactory dysfunction (DOPT). Participants receive three PRP injections over 4 weeks (Day 0, Day 14, Day 28), with follow-up visits at Month 3 and Month 6 after the first injection. Olfactory function is assessed using the Sniffin' Sticks Test (TDI score). Patient-reported outcomes include SNOT-22 and a visual analog scale (VAS) for perceived olfactory impairment. Safety is assessed through adverse event collection.

Participants needed: 30
Trial details
Age: 18-99Biological sex: AllType: InterventionalSponsor: Hospices Civils de LyonUpdated: Mar 20, 2026Locations: 1
Eligibility criteria

Adults with persistent (>6 months) non-tumoural olfactory dysfunction: age-relat... [+5]

Inflammatory rhinosinus disease (e.g., nasal polyposis) or granulomatosis with p... [+9]

Status: Not yet recruiting

Impact of Smell Testing on Health Outcomes

Smell dysfunction is frequent yet neglected. The sense of smell plays a crucial role in signaling disease, safety, and overall quality of life. However, the significance of a functional sense of smell in terms of health and well-being is often overlooked until one experiences a loss of smell due to injury or disease. Research demonstrates that individuals are often not self-aware of their smell dysfunction (i.e. they do not spontaneously report smell dysfunction as a symptom), especially if the changes are gradual, as in normal aging. Patients with smell dysfunction experience a marked reduction in quality of life, poor mental health, nutritional health, and brain health as well as increased 5- and 10-year mortality in older adults. This study explores whether or not enabling healthcare providers to offer resources and guidance on coping strategies for smell dysfunction improves health and wellbeing in those who experience it.

Participants needed: 1,000
Trial details
Phase: Phase 2Age: 7+Biological sex: AllType: InterventionalSponsor: Monell Chemical Senses CenterUpdated: Oct 30, 2025Locations: 1
Eligibility criteria

Not listed

Status: Not yet recruiting

Topical Versus Injection PRP for Olfactory Dysfunction

The goal of this clinical trial is to determine whether two different delivery methods of autologous platelet-rich plasma (PRP) can improve olfactory function in adults with persistent olfactory dysfunction lasting more than three months. The main questions it aims to answer are: 1. Does carrier-assisted topical application of PRP lead to comparable or better improvement in smell function than intranasal injection of PRP? 2. Which method provides greater patient comfort and fewer adverse effects? Researchers will compare carrier-assisted topical PRP application to intranasal PRP injection to see if one approach is more effective in restoring olfactory function. Participants will: 1. Receive a single PRP treatment delivered either by injection or via a PRP-soaked carrier placed into the olfactory cleft. 2. Continue daily olfactory training for three months following the intervention. 3. Undergo smell testing (Sniffin' Sticks) before and after treatment and complete quality-of-life questionnaires.

Participants needed: 60
Trial details
Phase: Phase 3Age: 18-80Biological sex: AllType: InterventionalSponsor: Taipei Veterans General Hospital, TaiwanUpdated: Sep 3, 2025Locations: 1
Eligibility criteria

Aged between 18 and 80 years, regardless of sex [+2]

Congenital anosmia [+2]

Status: Recruiting

The Impact of Endoscopic Endonasal Skull Base Surgery on Olfaction

In this study, the research team will investigate the incidence and etiology of olfactory dysfunction following endoscopic endonasal skull base surgery, by combining clinical assessments with histomolecular analysis.

Participants needed: 154
Trial details
Age: 18-70Biological sex: AllType: ObservationalSponsor: Universitaire Ziekenhuizen KU LeuvenUpdated: Apr 23, 2025Locations: 3
Eligibility criteria

Adult patients scheduled for endoscopic endonasal skull base surgery

Pre-existing anosmia [+1]

Status: Not yet recruiting

The Effect of Modified Olfactory Training on Postoperative Olfactory Dysfunction in Patients With CRS

The goal of this clinical trial is to validate the effectiveness of the modified olfactory training device, the main questions it aims to answer are: Is it possible that the device can treat postoperative olfactory dysfunction in patients with chronic sinusitis? Compared to the conventional device, how efficient is the modified olfactory training device for treating postoperative olfactory dysfunction in patients with chronic sinusitis?

Participants needed: 213
Trial details
Age: 18-80Biological sex: AllType: InterventionalSponsor: Peking University Third HospitalUpdated: Feb 20, 2025Locations: 1
Eligibility criteria

A diagnosis of CRSsNP based on the European Position Paper on Rhinosinusitis and... [+3]

Patients with olfactory impairment due to traumatic, congenital, toxic/drug-indu... [+4]

Status: Recruiting

The Efficacy of Modified Olfactory Training Method for Patients With Post-viral Olfactory Dysfunction

The goal of this clinical trial is to validate the effectiveness of the modified olfactory training device, the main questions it aims to answer are: Is the modified olfactory training device effective in treating patients with post-viral olfactory dysfunction? Compared to the conventional device, how efficient is the modified olfactory training device for improving olfactory function?

Participants needed: 150
Trial details
Age: 18-80Biological sex: AllType: InterventionalSponsor: Peking University Third HospitalUpdated: Feb 17, 2025Locations: 1
Eligibility criteria

Age 18-80 years old, gender not limited. [+2]

Patients with post-traumatic olfactory dysfunction, rhinosinusitis-related dysfu... [+10]

Status: Not yet recruiting

The Efficacy of Modified Olfactory Training for MCI High-Risk Individuals

The goal of this clinical trial is to validate the effectiveness of the modified olfactory training device, the main questions it aims to answer are: Is it possible that the device can delay the progression of MCI in older adults? Compared to the conventional device, how efficient is the modified olfactory training device for improving cognitive function?

Participants needed: 114
Trial details
Age: 60-90Biological sex: AllType: InterventionalSponsor: Peking University Third HospitalUpdated: Feb 12, 2025Locations: 1
Eligibility criteria

Age and Gender: Individuals aged 60-80 years, regardless of gender. [+3]

Comorbid Chronic Diseases or Severe Concurrent Illnesses: Individuals with condi...