Improving smell function in long COVID patients through training and stimulation
Official title: A Randomized Controlled Trial of Smell Training and Trigeminal Nerve Stimulation in the Treatment of COVID-related Persistent Smell Loss
Run by Medical University of South Carolina · NCT05855369 · Data updated 2026-11-12
This study is testing two at-home treatments to see if they can help people with long COVID regain their sense of smell and possibly improve other symptoms.
Quick facts
| Phase | Phase2; Phase3 |
|---|---|
| Study type | Interventional |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Enrollment | 145 (estimated) |
| Sponsor | Medical University of South Carolina Academic / other |
| Locations | 1 site (Charleston, South Carolina) |
| Status | Recruiting |
| Started | October 2, 2023 |
| Main results expected | May 31, 2028 |
| Study ends | May 31, 2028 |
| Registry record updated | April 2, 2026 |
| Trial ID | NCT05855369 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are individuals experiencing persistent smell loss after a COVID-19 infection who have not previously undergone smell training or trigeminal nerve stimulation.
✕Probably not a fit
Patients with a history of head injuries, sinonasal conditions, neurological disorders, or serious mental illnesses may not benefit from this study.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This study investigates the effectiveness of two at-home treatments for persistent smell loss associated with long COVID: smell training and non-invasive trigeminal nerve stimulation. Participants will engage in daily treatment sessions over 12 weeks, attend three in-person visits, and complete electronic questionnaires to assess their progress. The goal is to enhance the recovery of olfactory function, which may also alleviate other long COVID symptoms such as mood and cognitive impairments. The study aims to provide valuable insights into the treatment of smell dysfunction in long COVID patients.
Why it matters
Potential benefit: If successful, this study could significantly improve the sense of smell for patients suffering from long COVID-related smell loss.
How similar studies have gone: While smell training is being explored as a treatment for COVID-related smell loss, the combination of this with trigeminal nerve stimulation is a novel approach that has not been extensively tested.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * treatment-seeking for COVID-related persistent SL (anosmia, hyposmia, phantosmia or parosmia) * at least 1-month from SARS-coV-2 PCR-positive and/or rapid home-positive tests * normal sense of smell prior to COVID * naïve to both smell training (ST) and trigeminal nerve stimulation (TNS) * able to comprehend English and provide informed consent Exclusion Criteria: * history of head injury (e.g. sport, accident, combat blast) * sinonasal condition (e.g. upper respiratory infection, rhinosinusitis, polyps) * neurological disorder (e.g. epilepsy, neurodegenerative disorder, narcolepsy) * serious mental illness (e.g. schizophrenia, bipolar, or other psychotic disorder) * suicidal ideation within the last month * current (≤6 months) heavy cigarette smoker (heavy defined as ≥ 10 pack-years) * oral/nasal steroids or other intranasal medications within the last month * immunomodulatory medications * pregnant or trying to become pregnant
Where it's running
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Medical University of South Carolina
Charleston, South Carolina, United States Recruiting
Study contacts
- Study coordinator: Bernadette M. Cortese, Ph.D.
- Email: corteseb@musc.edu
- Phone: 843-792-6922
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.