Use of personal products that are not iso-osmolar to the vagina is an under-recognized promoter of BV. Using products that have the same osmolality protects the vaginal lining from damage and inflammation.
Types of Osmolality
Hyper-osmolar (high osmolality) lubricants draw water out of cells, shrinking them until they slough off the surface. As the cells shrivel, they send out pro-inflammatory cytokines to the immune system and reduce anti-inflammatory signals. Rapid shedding of the outer layer of epithelial cells make the tissue susceptible to infectious agents like bacteria and viruses.
Iso-osmolar (balanced osmolality) lubricants, on the other hand, do not change anything.
When hypo-osmolar (low osmolality) lubricants are applied, fluid is drawn into the epithelial cells, causing them to swell.
How Does the Osmolality of a Lubricant Affect Epithelial Cells?
Histology Reports show that just 4 hours of hyperosmotic lubricant application can cause death and sloughing of vaginal epithelial cells in a 3D cell culture model.
In a 2018 study by Dr. Melissa Herbst-Kralovetz's group, researchers examined the effects of lubricants on vaginal epithelial cell expression of immune markers and barrier function molecules. The results show that hyperosmotic lubricants alter the pattern of inflammatory markers and barrier function of epithelial cells. Good Clean Love's lubricant, an iso-osmotic product, does not alter these patterns. In this study, Conceptrol N-9 (containing known cytotoxin nonxynol-9) was used as a positive control for immune markers.