| Not Yet Recruiting | Slow-SPEED UK: A Double-Blind Randomised Feasibility Trial NCT06600438 | Queen Mary University of London | N/A |
| Not Yet Recruiting | Longitudinal Deep Phenotyping of Central Mechanisms in Dysosmia: A Pilot Study Using Electrobulbogram (EBG), F NCT07149428 | National Institute on Deafness and Other Communication Disorders (NIDCD) | — |
| Not Yet Recruiting | Intranasal Platelet-Rich Plasma With or Without Topical Insulin for Post-Inflammatory Anosmia NCT07383415 | Amin Javer | N/A |
| Not Yet Recruiting | Topical Versus Injection PRP for Olfactory Dysfunction NCT07151703 | Taipei Veterans General Hospital, Taiwan | Phase 3 |
| Not Yet Recruiting | Efficacy of Platelet-rich Plasma in Management of Anosmia NCT06930248 | Sohag University | N/A |
| Recruiting | Scents of Progress: Leveraging a Novel Device for Olfactory Training in Older Adults NCT06733636 | Johns Hopkins University | N/A |
| Withdrawn | Theophylline Nasal Spray for PD-Related Hyposmia and Anosmia NCT06498687 | University of Nebraska | Phase 1 |
| Completed | Multimodal Chewing Gum Flavour Training to Aid Flavour Perception Recovery - a Pilot Study. NCT07498062 | University of Nottingham | N/A |
| Recruiting | Investigating the Efficacy of OMT to Recover Olfactory Perception After COVID-19 NCT06766279 | Burrell College of Osteopathic Medicine | N/A |
| Active Not Recruiting | Sodium Citrate in Smell Retraining for People With Post-COVID-19 Olfactory Dysfunction NCT06204432 | University of North Carolina, Chapel Hill | Phase 2 |
| Active Not Recruiting | Characteristics of the Anosmic Olfactory Mucosa NCT05562050 | Nicolai Nielsen | — |
| Completed | Chemosensory Dysfunction and Recovery in Endoscopic Endonasal Skull Base Surgery NCT05912881 | Johns Hopkins University | N/A |
| Active Not Recruiting | Longitudinal At Home Smell Testing to Detect Infection by SARS-CoV-2 NCT05040659 | Massachusetts General Hospital | — |
| Completed | Stellate Ganglion Block for COVID-19-Induced Olfactory Dysfunction NCT05445921 | Washington University School of Medicine | Phase 1 / Phase 2 |
| Completed | Stellate Ganglion Block to Treat Long COVID 19 Case Series NCT05812209 | Metamorphosis LTD | — |
| Recruiting | Olfactory Training on Smell Dysfunction Patients in HK NCT05364125 | Pamela Youde Nethersole Eastern Hospital | N/A |
| Recruiting | Efficacy of Photobiomodulation in the Rehabilitation of Olfactory Dysfunctions Induced by Long COVID-19 NCT06423495 | Gaffree & Guinle Universitary Hospital | N/A |
| Unknown | Value of Platelet-Rich Plasma in Post Severe Acute Respiratory Syndrome Coronavirus 2 NCT05395845 | Aya abdelnasser hassani | EARLY_Phase 1 |
| Withdrawn | Lactoferrin for COVID-19-Induced Taste or Smell Abnormality NCT05760079 | Wake Forest University Health Sciences | N/A |
| Recruiting | Olfactory Training As a Treatment for Olfactory Dysfunction Post COVID-19 NCT05384561 | Université du Québec à Trois-Rivières | N/A |
| Completed | Efficacy of Gabapentin for Post-Covid-19 Olfactory Dysfunction NCT05184192 | Washington University School of Medicine | Phase 2 |
| Terminated | Treatment of Pediatric Patients That Lost Sense of Smell Due to COVID-19 NCT04964414 | Amanda Stapleton | Phase 1 / Phase 2 |
| Withdrawn | Coronavirus Smell Therapy for Anosmia Recovery NCT04422275 | Washington University School of Medicine | Phase 2 |
| Unknown | Olfactory Training for Olfactory Dysfunction After Coronavirus Disease - 19 (COVID-19) NCT04764981 | Universidade do Estado do Pará | N/A |
| Unknown | Role of Ivermectin Nanosuspension as Nasal Spray in Treatment of Persistant Post covid19 Anosmia NCT04951362 | South Valley University | Phase 2 / Phase 3 |
| Unknown | Anosmia and / or Ageusia and Early Corticosteroid Use NCT04528329 | ClinAmygate | Phase 4 |
| Completed | Smell in Covid-19 and Efficacy of Nasal Theophylline NCT04789499 | Washington University School of Medicine | Phase 2 |
| Completed | Study of Hesperidin Therapy on COVID-19 Symptoms (HESPERIDIN) NCT04715932 | Montreal Heart Institute | Phase 2 |
| Completed | Effectiveness and Safety of Platelet Rich Plasma (PRP) on Persistent Olfactory Dysfunction Related to COVID-19 NCT05226546 | Centre Hospitalier Universitaire Saint Pierre | Phase 2 / Phase 3 |
| Completed | Visual-OLfactory Training in Participants With COVID-19 Resultant Loss of Smell NCT04710394 | Washington University School of Medicine | N/A |
| Completed | Intranasal Insulin for COVID-19-related Smell Loss NCT05461365 | Universidad Panamericana | Phase 3 |
| Recruiting | The Nasal Microbiome and Its Importance in Disease NCT05061329 | University of Aarhus | — |
| Completed | Olfactory Disfunction and Co-ultraPEALut NCT04853836 | University Of Perugia | Phase 4 |
| Completed | The Clinical Applicability of the 'TIB' Olfactory Test Device NCT05152030 | Taichung Veterans General Hospital | — |
| Completed | Clinical Assessment of Insulin Fast Dissolving Film in Treatment of Post Infection Anosmia NCT04657809 | Soad Ali | Phase 2 |
| Completed | Corticosteroid Nasal Spray in COVID-19 Anosmia NCT04484493 | Benha University | Phase 3 |
| Completed | COVID-19 Anosmia Study NCT04495816 | Icahn School of Medicine at Mount Sinai | Phase 2 |
| Unknown | Prevalence and Outcomes of Olfactory and Gustatory Dysfunctions in Patients With COVID-19 NCT04524754 | Ain Shams University | — |
| Completed | Assessment of Olfactory Dysfunction in SARS CoV-2 (COVID-19) Infection NCT04466982 | Cambridge University Hospitals NHS Foundation Trust | — |
| Completed | COVID-19 in Patients With Anosmia in Egypt NCT04473157 | Ain Shams University | — |
| Completed | Investigating Anosmia and Ageusia in COVID-19 Adult Patients in Saudi Arabia NCT04388618 | Princess Nourah Bint Abdulrahman University | — |
| Completed | Malaysian COVID-19 Anosmia Study (Phase 1) - A Nationwide Multicentre Cross-Sectional Study NCT04390165 | Hospital Sultanah Bahiyah | — |
| Unknown | Malaysian COVID-19 Anosmia Study (Phase 2) - A Nationwide Multicentre Case-Control Study NCT04384042 | Hospital Sultanah Bahiyah | — |
| Completed | Anosmia and Covid-19 NCT05246059 | University College, London | N/A |
| Withdrawn | Brain MRI Imaging in Patients With SARS-Cov2 (COVID-19) Infection With or Without Anosmia NCT04408391 | Centre Hospitalier Universitaire de Nīmes | — |
| Completed | Trial Evaluating the Efficacy of Local Budesonide Therapy in the Management of Hyposmia in COVID-19 Patients W NCT04361474 | Fondation Ophtalmologique Adolphe de Rothschild | Phase 3 |
| Completed | BNO 1030 Extract (Imupret) in the Treatment of Mild Forms of COVID-19 NCT04797936 | Ivano-Frankivsk National Medical University | Phase 4 |
| Completed | Finding Out if COVID-19 Infection Can be pREdicted by ChAnges in Smell and/or Taste NCT04377815 | University College, London | — |
| Completed | Smell Changes & Efficacy of Nasal Theophylline NCT03990766 | Washington University School of Medicine | Phase 2 |
| Terminated | NAC for Head Trauma-induced Anosmia NCT03680911 | University of Miami | Phase 3 |
| Withdrawn | Does Cardiopulmonary Bypass Change Olfaction? NCT02179554 | Manchester University NHS Foundation Trust | — |
| Completed | NAC Trial for Anosmia NCT02481609 | University of Miami | EARLY_Phase 1 |
| Completed | Clinical Utility of Olfactory Rehabilitation: Treatment for Pacients With Neurosensorial Anosmia NCT04957563 | Cristina Gomez Calero | N/A |