As a result, VIP induces an increase in vaginal blood flow accompanied by an increase in vaginal lubrication. The findings suggest that VIP may participate in the control of the local physiological changes observed during sexual arousal: genital vasodilation and increase in vaginal lubrication. Vaginal dryness
Insufficient lubrication or vaginal dryness can cause dyspareunia, which is a type of sexual pain disorder. While vaginal dryness is considered an indicator for sexual arousal disorder, vaginal dryness may also result from insufficient excitement and stimulation or from hormonal changes caused by menopause (potentially causing atrophic vaginitis), pregnancy, or breast-feeding. Irritation from contraceptive creams and foams can also cause dryness, as can fear and anxiety about sexual intimacy. Vaginal dryness can also be a symptom of Sjögren syndrome (SS), a chronic autoimmune disorder in which the body destroys moisture-producing glands. Certain medications, including some over-the-counter antihistamines, as well as life events such as pregnancy, lactation, menopause, aging or diseases such as diabetes, will inhibit lubrication. Medicines with anticholinergic or sympathomimetic effects will dry out the mucosal or "wet" tissues of the vagina. Such medicines include many common drugs for allergenic, cardiovascular, psychiatric, and other medical conditions. Oral contraceptives may also increase or decrease vaginal lubrication. Older women produce less vaginal lubrication and reduced estrogen levels may be associated with increased vaginal dryness. Artificial lubricants
When a woman is experiencing vaginal dryness before sexual activity, sexual intercourse may be uncomfortable or painful for her.
A personal lubricant can be applied to the vaginal opening, the penis, or both, to augment the naturally produced lubrication and prevent or reduce the discomfort or pain. More rarely, a vaginal suppository may be inserted prior to intercourse. Oil-based lubricants can weaken latex and reduce the effectiveness of condoms, latex gloves, or dental dams as either forms of birth control or for protection from sexually transmitted diseases, so water- or silicone-based lubricants are often used instead. The use of an artificial lubricant can make sexual intercourse less painful for a woman, but does not address the underlying cause of the vaginal dryness itself. Both canola oil and mineral oil are recommended by the American Society for Reproductive Medicine as fertility-preserving types of personal lubricant. Dry sex
Some people practice dry sex, which involves the removal of vaginal lubrication in some way. The rationale for the practice seems to be for cleansing purposes and to enhance the sexual pleasure of the penetrating partner. However, besides making sexual intercourse painful for the female, the practice is believed to increase the risk of transmitting sexually transmitted diseases for both partners, such as HIV, whose risk of transmission is increased by lacerations in the vaginal tissue resulting from the lack of lubrication. See also
References
External links

Mayo Clinic - Vaginal dryness