Vaginal pH-lowering effect of locally applied vitamin C in subjects with high vaginal pH.

The primary objective of this randomized, double-blind, controlled study was the assessment of the pH-lowering effect of three different formulations of a vaginal device each containing 250 mg vitamin C. Overall, 39 women with vaginal pH >or=5, without evidence of vaginal infections, were randomly assigned to receive one of the three formulations for 6 days. The primary parameter assessed was vaginal pH, performed by the physician at the baseline and final visits and by the subjects each day during the application period; secondary parameters included the acceptability and safety profile of the tested devices. A decrease in pH to the normal range in all groups was observed following the first application, with stable low values during the whole study period. No statistically significant differences were seen among the three groups, while statistically significant within-group differences were observed. Acceptability and tolerability were rated as very good/good in most cases. The study results confirm that the vaginal application of vitamin C has an effective and long-lasting vaginal pH-lowering effect.