- Polyquaterniums, a class of chemicals common in cosmetics, seem to increase HIV replication by almost four times in lab tests. A Population Council study found this ingredient in three of four HIV-enhancing Astroglide brand lubes: Astroglide Liquid, Astroglide Warming Liquid, Astroglide Glyercin & Paraben Free liquid and Astroglide Silken Secret.
- Osmolality refers to the concentration of salts, sugars and other substances (solutes) present in a lube. Hypo-osmolar lubes have a lower concentration of solutes than human cells and cause the cells to swell with water and burst. Hyperosmolar lubes cause cells to shrink and become brittle. Iso-osmolar lubes don’t affect cells because their concentrations are identical. Most water-based lubes are hyperosmolar and damaging.
- pH balance is acidic in the vagina and neutral in the rectum. Many lubes are designed for the vagina—does the difference in pH mean they affect the rectum differently?
- Good and bad bacteria live in a delicate balance in the vagina and gut. Will disrupting this balance make the rectum more susceptible to HIV?
- Viscosity is the slippery quality that gives lube its feel and texture. Glycerin, in water-based lubes, adds to viscosity. It also makes lubes hyperosmolar—and destructive to epithelium. When a rectal microbicide now in trials proved harmful to the epithelium, researchers solved the problem by lowering the glycerin content.