How do vaginal lubricants work to treat vaginal dryness?

They lubricate. They do not treat the cause, they make it so you are lubricated. In many peri-menopausal and post menopausal women , the dryness is caused by lack of estrogen, so a small dose of vaginal estrogen twice a week can cure this problem. Sometimes lubricants are also used. If you are younger , you need to have your estrogen levels checked as they may be too low and this can be treated., so see your gyn.