This study is exploring if a sodium citrate nasal spray can help people who lost their sense of smell after having COVID-19. Sodium citrate is a chemical that can help improve smell when used in a nasal spray. Participants will use the spray twice daily for 12 weeks and practice smelling different scents like lavender and lemon.

Before starting, participants will have a smell test with "Sniffin' Sticks," a tool that helps measure smell ability. There are two groups: one using sodium citrate spray and the other using normal saline (saltwater) spray. Both groups will follow the same training exercises, and results will be compared after 12 weeks.

Researchers want to see if the sodium citrate group shows more improvement in their sense of smell than the saline group. Participants need to be at least 18 years old and have had a loss of smell for over three months after a positive COVID-19 test.

• The study lasts 12 weeks, with daily nasal spray use and smell practice.
• Participants must be able to return to UNC Health for follow-ups.
• The study is for adults with smell loss after COVID-19.