Summary of COVID-19 niclosamide studies


1. Kim et al., A randomized, double-blind, placebo-controlled trial of niclosamide nanohybrid for the treatment of patients with mild to moderate COVID-19
197 patient niclosamide early treatment RCT: 29% faster recovery (p=0.008) and 56% improved viral clearance (p=0.16).
RCT 300 patients with mild to moderate COVID-19 showing significant symptom improvement with niclosamide nanohybrid (CP-COV03). The high-dose group showed no significant benefit in time to symptom improvement in the primary analysis, which authors attribute to gastrointestinal side effects from excess magnesium oxide content confounding symptom assessment. A post-hoc analysis with three COVID-19 representative symptoms showed significant improvement in both groups.
Jul 2025, Nature Communications, https://www.nature.com/articles/s41467-025-62423-4, https://c19p.org/kim27

2. Cairns et al., Efficacy of Niclosamide vs Placebo in SARS-CoV-2 Respiratory Viral Clearance, Viral Shedding, and Duration of Symptoms Among Patients With Mild to Moderate COVID-19
67 patient niclosamide early treatment RCT: 18% faster recovery (p=0.28) and 24% improved viral clearance (p=0.45).
RCT with 73 mild to moderate outpatients, showing faster recovery and improved viral clearance with niclosamide, without statistical significance. Greater improvements in recovery were seen for high-risk patients, again without statistical significance. The study was underpowered due to decreased enrollment related to falling COVID-19 cases.
Feb 2022, JAMA Network Open, https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2788857, https://c19p.org/cairns

3. Rank et al., A Phase 2/3 Randomized and Placebo-Controlled Study of ANA001 in Moderate and Severe COVID-19 Patients
120 patient niclosamide late treatment RCT: 30% lower mortality (p=1), 70% faster recovery (p=0.97), 57% higher hospital discharge (p=0.98), and no change in viral clearance (p=1).
RCT 46 moderate to severe hospitalized COVID-19 patients showing shorter time to discharge and WHO clinical scale improvement with niclosamide, but no significant difference for resolution of all symptoms and viral clearance.
Aug 2024, NCT04603924, https://clinicaltrials.gov/study/NCT04603924, https://c19p.org/rank

4. Humphrey et al., Prophylaxis for renal patients at risk of COVID-19 infection: results from the intranasal niclosamide randomised, double blinded, placebo controlled arm of the PROTECT-V platform trial
1,651 patient niclosamide prophylaxis RCT: 80% lower ventilation (p=0.25), 13% lower hospitalization (p=0.71), and 2% more symptomatic cases (p=0.89).
RCT 1,651 patients with kidney disease showing no significant difference in symptomatic COVID-19, hospitalization, or mortality with intranasal niclosamide compared to placebo. The UNI911 nasal spray had very poor adherence and a higher withdrawal rate (40% vs. 23.8% for placebo), partially due to local nasal and upper airway irritation.
Jul 2023, BMC Infectious Diseases, https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-025-10584-4, https://c19p.org/humphrey

5. Abdulamir et al., A randomised controlled trial of effectiveness and safety of Niclosamide as add on therapy to the standard of care measures in COVID-19 management
150 patient niclosamide late treatment RCT: 39% improved recovery (p=0.007).
RCT with 75 COVID-19 patients showing significantly faster recovery but no change in mortality with niclosamide. The treatment group had more patients aged 60+ and more patients treated over a week after symptom onset.
Sep 2021, Annals of Medicine & Surgery, https://www.sciencedirect.com/science/article/pii/S2049080121007299, https://c19p.org/abdulamir

6. First Wave BioPharma et al., A 2-Part, 2-Arm, Phase 2, Randomized, Double-Blind, Placebo-Controlled Study on the Safety and Efficacy of Niclosamide in Patients With COVID-19 With Gastrointestinal Infection
118 patient niclosamide late treatment RCT: 23% improved viral clearance (p=0.61).
RCT 118 hospitalized patients with gastrointestinal infection showing no significant difference in viral clearance with niclosamide. Viral clearance results are available on clinicaltrials.gov but clinical results are missing.
Apr 2023, First Wave BioPharma, NCT04858425, https://clinicaltrials.gov/study/NCT04858425, https://c19p.org/firstwave

7. Siripongboonsitti et al., A Randomized Trial to Assess the Acceleration of Viral Clearance by the Combination Favipiravir/Ivermectin/Niclosamide in Mild-to-Moderate COVID-19 Adult Patients (FINCOV)
60 patient niclosamide early treatment RCT: 39% improved recovery (p=0.19) and 6% improved viral clearance (p=0.75).
RCT 60 low-risk outpatients, median age 31, with mild to moderate COVID-19 showing no significant differences with combined favipiravir/ivermectin/niclosamide treatment compared to favipiravir alone. There was limited room for improvement with almost no progression and no hospitalization, ICU admission, supplemental oxygen, or mortality. The combined group showed significantly improved visual analog scale (VAS) scores for cough, runny nose, and diarrhea from day 3. Authors note that "the WHO-CPS were significantly decreased among FPV/IVM/NCL vs FPV alone on day 10", however the degree of improvement cannot be determined based on the values reported. Authors state that "All data generated or analyzed during this study are included in this published article", which is incorrect - only summary statistics are published. The trial registration states that data will not be made available. This raises concerns, especially given many inconsistencies in the published data:..
Mar 2024, J. Infection and Public Health, https://www.sciencedirect.com/science/article/pii/S1876034124001060, https://c19p.org/siripongboonsitti6nc