Life Science Encyclopedia

Pre-ejaculate (also known as pre-ejaculatory fluid or Cowper's fluid, and colloquially as precum) is the clear, colorless, viscous fluid that is issued from the urethra of a man's penis when he is sexually aroused. The fluid is usually secreted by Cowper's glands during arousal, masturbation, foreplay or at an early stage during sex, some time before the man fully reaches orgasm and semen is ejaculated.

Function

Pre-ejaculatory fluid prepares the urethra for the passage of semen by neutralizing acidity due to any residual urine. It also lubricates the movement of the penis, and of the foreskin over the glans. The amount of fluid that the human male issues varies widely among individuals, from imperceptible amounts to a copious flow.

Presence or absence of sperm

There have been no large-scale studies of sperm in pre-ejaculate, but some smaller-scale studies suggest that any sperm present may be ineffectual at causing pregnancy.^[1][2] This may account for the surprisingly low pregnancy rate (approximately 4% per year) among couples that practice perfect use of coitus interruptus.

It is likely, however, that pre-ejaculate which follows a recent ejaculation will contain more sperm, as some ejaculate is always left in the duct after orgasm.^[3]

Presence of HIV

The same studies have shown the presence of HIV, which can lead to the disease AIDS, also in pre-ejaculate.^[1]

References