Safety Study of Lactobacillus Administered Vaginally to Healthy Women

The purpose of this study is to demonstrate that LACTIN-V is safe, well tolerated, and acceptable to healthy pre-menopausal women when administered vaginally using pre-filled applicators at doses of 150 mg (5.0 x 10\^8 CFU), 300 mg (1.0 x 10\^9 CFU), or 600 mg (2.0 x 10\^9 CFU) daily for 5 consecutive days as compared to placebo applicators containing 150 mg, 300 mg, or 600 mg of a matching placebo formulation without Lactobacillus crispatus CTV-05. Safety will be assessed by: * Incidence and severity of adverse events through assessing symptoms, physical examination findings, and signs of irritation involving the external genitalia, cervix or vagina, including disruption of the epithelium and blood vessels as seen on pelvic examination and colposcopy. * Laboratory parameters including urinalysis, a complete blood count (CBC) with differential, and chemistry panels to assess systemic effects of the study product. Tolerability will be assessed by: * The proportion of participants who discontinue study product use due to overt adverse events * The proportion of participants who complete the full dosing schedule Acceptability will be assessed by: \- Self-administered questionnaires and focus group discussions about acceptability of the study product