Anal play should never be uncomfortable for either person, so while using lubricant is a must, the value of using an anal lube designed to support these more vulnerable tissues is becoming more recognised. Experiencing safe and friction free pleasure are our main aims with YES BUT, but it’s not only about the lubricity. Vaginal lubricants are designed to be acidic. That’s not ok for anal play, and strong chemicals like glycerine and polypropylene glycol are known to damage the lining of the rectum, see study links below. *We mentioned osmolality. Anal play gets some of our more vulnerable tissues exposed to lubricants, and chemical ingredients that damage these tissues can make STD transmission and HIV in particular, more likely. YES BUT has been designed to match these vulnerable tissues in two ways. Firstly the pH is balanced to match rectal pH (neutral) not vaginal pH (fairly acidic) and secondly the strength of the ingredients used in YES BUT matches these tissues. This ingredients’ strength is called Osmolality