Tampons lubricated with pH-balanced gel fail to increase the acidity of the vagina, which could reduce infections, according to a report in the BJOG: An International Journal of Obstetrics and Gynaecology.

“There is no evidence that the product we investigated controls vaginal pH,” Dr. Louise Melvin from Family Planning and Well Woman Clinic, Edinburgh, UK told Reuters Health, “but women preferred them to tampons without lubrication.”

Reduced vaginal acidity - a natural occurrence during and shortly after menstruation - is associated with bacterial infections of the vagina, explain Melvin and colleagues, and it has been suggested that maintaining acidity in the vagina might reduce the rate of these infections, along with their troublesome symptoms.

The team investigated the ability of tampons having a pH-balanced gel to maintain a vaginal pH of 4.5 or lower, which is fairly acidic. They assigned 98 women to use tampons with an acidity-promoting gel or conventional tampons with standard lubricating gel. The women used tampons without gel in the preceding cycle.

“No significant difference was observed between tampons with the standard gel formulation, the pH-balanced gel and unlubricated tampons in terms of vaginal pH,” microbiological evidence of infection or gynecologic appearance, Melvin and colleagues report.

Women reported higher average satisfaction scores for lubricated tampons than for unlubricated tampons.

“Although the study did not demonstrate any major benefits of tampon lubrication with a pH-balanced gel, it does provide reassuring data on the safety and the acceptability of lubricated tampons and adds to the limited volume of published literature on the effects of tampons on the vaginal milieu,” the researchers conclude.

“If the product design could be modified to deliver a larger amount of gel to the vagina, it may be possible to control vaginal pH more effectively,” the authors note.

SOURCE: BJOG, April 2008.