Efficacy of Oral Zinc Sulfate for the Clearance of Cervical Low-Grade Squamous Intraepithelial Lesions: A Randomized Controlled Trial

Oral Zinc Sulfate and LSIL

Abstract

Background: Low-grade squamous intraepithelial lesions (LSIL) of the cervix are commonly managed with surveillance because of their high spontaneous regression rate. Zinc has been proposed as a potential therapeutic agent owing to its immunomodulatory and antioxidant properties. This study evaluated the efficacy of oral zinc sulfate in promoting the regression of cervical LSIL compared with standard follow-up.

Methods: In this randomized controlled trial, Thai women aged ≥20 years with histopathologically confirmed cervical LSIL diagnosed by colposcopy-directed biopsy were randomly assigned to receive either oral zinc sulfate (440 mg daily for 12 weeks) or standard follow-up alone. The primary outcome was the clearance of abnormal cervical cytology at 12 and 24 weeks after treatment initiation.

Results: At 12 weeks, abnormal cervical cytology had cleared in 58.2% of participants in the zinc group and 65.4% in the control group (risk ratio (RR,0.83; 95% CI: 0.51 to 1.33; p=0.43). At 24 weeks, clearance rates were 49.2% and 61.8%, respectively (RR,1.26; 95% CI: 0.90 to 1.77; p=0.18). No statistically significant differences were observed between the two groups at either follow-up time point. No serious adverse events related to zinc supplementation were reported.

Conclusions: Oral zinc sulfate administered at a dose of 440 mg daily for 12 weeks did not improve the regression of cervical LSIL compared with standard follow-up. These findings do not support the routine use of high-dose oral zinc sulfate as a therapeutic intervention for women with established LSIL, particularly in populations without evidence of zinc deficiency.