Difference between YES® WB and YES® BUT

YES^® WB is a vaginal lubricant  – designed for vaginal use. The specific parameters that make a lubricant suitable for vaginal use are as follows:

1. pH matched to the typical vaginal environment (pH4.0-4.5) to maintain vaginal health, as vaginal microflora is predominately Lactobacilli which creates the acidic environment
2. Iso (the same as) or hypo (slightly lower than) osmotic to vaginal tissues. This means that the strength of the formulation, in particular the quantity and quality of dissolved molecules in the lubricant, matches human plasma and human cell osmolality. The close match (Iso or slightly hypo) ensures no tissues are irritated by water being pulled out of the tissues. All glycerin based lubricants are highly Hyper-osmotic and this can cause cell damage and irritation, and increases the risk of STD transmission through broken tissues. Slightly hypo osmotic lubricants will release water into dry tissues, with no tissue damage.

YES^®  WB is slightly hypo-osmotic to vaginal tissues and has pH4.0.

YES^®  BUT is an anal lubricant – designed for anal use. The specific parameters that make a lubricant suitable for anal use are as follows:

1. pH matched to typical rectal pH (pH7.0-8.0).  The rectum has minimal pH buffering ability (there is little free fluid available to dilute or change the lubricant pH, unlike the vagina) and the rectal microflora is predominantly anaerobic gram negative and gram-positive bacteria, which is very different to vaginal microflora.
2. Iso osmotic to rectal tissues which are typically 270-290 mOsm/kg (same as plasma & vaginal tissues). The Iso-osmotic nature is more important for anal lubricants as the rectal tissues are more likely to be damaged by a hyper-osmotic lubricant. Rectal epithelium is much thinner and more fragile than vaginal tissue, and provides a greater surface area for infection, plus one of the functions of these rectal tissues is to absorb excess fluids from the rectum. Damage to vaginal or rectal tissues is a major risk factor in STD transmission, and in particular HIV, so using an Iso-osmotic rectal lubricant minimises the risk of tissue damage and therefor HIV transmission.

YES^®  BUT is Iso-osmotic to rectal tissues and matches rectal pH at pH7.5