Olive oil, almond oil, and coconut oil (though coconut oil is controversial, according to gynos) might not be the best lubricants, as they will decrease latex condoms' effectiveness and can lead to a buildup of bacteria. "A healthy vagina has a slightly acidic pH of 3.8 to 4.5, so exposing your vagina on a regular basis to things that raise the pH can upset the healthy lactobacilli and the microbiome, which can predispose to yeast or BV," explains Dr. Karen Brodman, MD, an ob-gyn in New York, to POPSUGAR. Plus, the thickness of such oils may hold on to bacteria and lead to increased risk of infection, adds DeLucia.