is normally acidic, so the deposit of pre-ejaculate before the emission of semen may change the vaginal environment to promote sperm survival. Pre-ejaculate also acts as a lubricant during sexual activity, and plays a role in semen coagulation.

Low levels or no sperm exists in pre-ejaculate, although studies examined small samples of men. Two contrary studies found mixed evidence, including individual cases of a high sperm concentration. There is evidence - dating to a 1966 Masters and Johnson