Pre-ejaculate (also known as pre-ejaculatory fluid, pre-seminal fluid or Cowper's fluid, and colloquially as ''pre-cum'') is a clear, colorless,

viscous The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the in ...

fluid that is emitted from the

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra ...

of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

during

sexual arousal Sexual arousal (also known as sexual excitement) describes the physiological and psychological responses in preparation for sexual intercourse or when exposed to sexual stimuli. A number of physiological responses occur in the body and mind a ...

. It is similar in composition to

semen Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Sem ...

but has distinct chemical differences. The presence of

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, ...

in the fluid is variable from low to absent. Pre-ejaculate functions as a

lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...

and an

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...

neutralizer.

Origin and composition

The fluid is discharged from the urethra of the penis during

arousal Arousal is the physiological and psychological state of being awoken or of sense organs stimulated to a point of perception. It involves activation of the ascending reticular activating system (ARAS) in the brain, which mediates wakefulness, th ...

masturbation Masturbation is the sexual stimulation of one's own genitals for sexual arousal or other sexual pleasure, usually to the point of orgasm. The stimulation may involve hands, fingers, everyday objects, sex toys such as vibrators, or combinat ...

foreplay Foreplay is a set of emotionally and physically intimate acts between one or more people meant to create sexual arousal and desire for sexual activity. Although foreplay is typically understood as physical sexual activity, nonphysical activiti ...

or at an early stage during

sexual intercourse Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal pene ...

, some time before the individual fully reaches

orgasm Orgasm (from Greek , ; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region chara ...

and semen is ejaculated. It is primarily produced by the

bulbourethral gland The bulbourethral glands or Cowper's glands (named for English anatomist William Cowper) are two small exocrine glands in the reproductive system of many male mammals (of all domesticated animals, they are absent only in dogs). They are homolo ...

s ( Cowper's glands), with the glands of Littré (the mucus-secreting urethral glands) also contributing. The amount of fluid that is issued varies widely among individuals. Some individuals do not produce any pre-ejaculate fluid, while others emit as much as . The outflow of pre-ejaculate is independent of mechanical stimulation of the penis or an erection, and can be triggered by erotic thoughts alone. Pre-ejaculate fluid contains chemicals associated with semen, such as

acid phosphatase Acid phosphatase (EC 3.1.3.2, acid phosphomonoesterase', phosphomonoesterase, glycerophosphatase, acid monophosphatase, acid phosphohydrolase, acid phosphomonoester hydrolase, uteroferrin, acid nucleoside diphosphate phosphatase, orthophosphoric-m ...

, but other semen markers, such as gamma-glutamyltransferase, are absent.

Function and risks

Pre-ejaculate neutralizes residual acidity in the urethra caused by

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...

, creating a more favorable environment for the passage of sperm. The

vagina In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...

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 Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism ...

. 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. Popular belief – dating to a 1966

Masters and Johnson The Masters and Johnson research team, composed of William H. Masters and Virginia E. Johnson, pioneered research into the nature of human sexual response and the diagnosis and treatment of sexual disorders and dysfunctions from 1957 until the 1 ...

study – stated that pre-ejaculate may contain sperm that can cause pregnancy, which is a common basis of argument against the use of

coitus interruptus ''Coitus interruptus'', also known as withdrawal, pulling out or the pull-out method, is a method of birth control in which a man, during sexual intercourse, withdraws his penis from a woman's vagina prior to ejaculation and then directs his ej ...

(withdrawal) as a contraceptive method. Studies have demonstrated the presence of HIV in most pre-ejaculate samples from infected men.

Overproduction

In rare cases, an individual may produce an excessive amount of pre-ejaculate fluid that can be a cause of embarrassment or irritation. A few case reports have indicated satisfactory results when such individuals are treated with a 5-alpha-reductase inhibitor, such as

finasteride Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women and as a part of h ...

References

{{DEFAULTSORT:Pre-Ejaculate Semen Ejaculation Men's health

Origin and composition

Function and risks

Overproduction

See also

References