NAC Trial for Anosmia

Pilot Study of Topical Intranasal N-acetyl Cysteine Administration for the Treatment of Anosmia

Status

Completed

Phases

Early Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02481609

Enrollment

Registered

2015-06-25

Start date

2014-07-31

Completion date

2017-12-01

Last updated

2018-03-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anosmia

Keywords

Loss of Smell, Olfaction, Hyposmia

Brief summary

The purpose of this research study is to evaluate the use of NAC in the treatment of anosmia (a loss of the sense of smell). This drug is already approved by the Food and Drug Administration (FDA) for oral or pulmonary (lung) inhaled use for other medical conditions. However, there is research evidence that the medication may promote nerve recovery (help nerves work better after they are damaged). Since anosmia involves nerve problems, we believe the nasal spray may help treat anosmia. The medication has been in use for many years for other conditions, without safety problems.

Interventions

DRUGN-acetyl cysteine (NAC)

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* adults at least 18 years of age with documented microsmia or anosmia by University of Pennsylvania Smell Identification Test. * patients must have no evidence of active sinonasal disease by nasal endoscopy or CT or MRI * negative CT or MRI

Exclusion criteria

* adults unable to consent * individuals who are not yet adults (infants, children, teenagers) * pregnant women, prisoners, employees or subordinates, * patients with known sensitivity to NAC or severe asthma * patients with sinus or central disease on CT or MRI imaging.

Design outcomes

Primary

Measure	Time frame	Description
Change in the Smell Identification Test score	Baseline and three months after completion of treatment	Sense of smell is measured using the Smell Identification Test (a standardized 40-item forced choice self administered microencapsulated odor scratch-and-sniff style test )

Secondary

Measure	Time frame	Description
Change in Sino-Nasal Outcome Test (SNOT-20) score	Baseline and three months after completion of treatment	Validated quality of life assessment tool for nasal and sinus disease patients

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026