Vaginal absorption of surfactants and chemicals: a narrative review

Vaginally used products can contain toxic chemicals such as surfactants, per- and polyfluoroalkyl substances, metals, and others. Chronic dermal exposure to these chemicals can lead to adverse health effects, however the effects of vaginal exposure are unknown. The objective of this review is to evaluate if surfactants and other chemicals applied intravaginally can be absorbed systemically or negatively impact vaginal cells. We conducted a narrative review using the PubMed database. We included studies about vaginally administered chemicals in models representing vaginal exposure. We excluded reviews and studies that only evaluated ecosystem toxicity. Our search yielded 3,131 articles and 13 papers met our inclusion criteria. We reviewed the absorption potential of 24 surfactants, chemicals, and metals. All of the surfactants reviewed were absorbed into vaginal cells, but effects were dependent on concentration and polarity. Nonoxynol-9 consistently inhibited cell growth, was cytotoxic to vaginal cells, and had a high irritation potency. Many reviewed surfactants were found in commercial personal lubricants, including the cytotoxic surfactant nonoxynol-9. Given its irritation potential, we recommend against use of nonoxynol-9 in vaginally applied formulations. Only one study evaluated systemic absorption of surfactants and other chemicals, highlighting a large gap in research of vaginally applie formulations.