Bulbourethral Glands

The bulbourethral glands, also called Cowper's glands, are two small glands in the male reproductive system that release a clear, slippery fluid into the urethra during sexual arousal. This fluid helps lubricate the urethra and may help neutralize residual acidity before ejaculation. While they are small, bulbourethral glands matter because they contribute to semen transport, sexual function, and the overall environment sperm move through.

At a glance
What are bulbourethral glands?
Where are they located?
What do bulbourethral glands do?
Why they matter in men's health and fertility
Bulbourethral glands and pre-ejaculate
What's normal vs what's not?
Symptoms and common problems
What can affect the bulbourethral glands?
How doctors evaluate bulbourethral gland problems
Treatment and management
Can bulbourethral gland issues affect fertility?
Related terms and comparisons
Questions to ask your doctor
Frequently asked questions
References

At a glance

Bulbourethral glands are paired male reproductive glands located below the prostate.
They are also known as Cowper's glands.
They release a clear mucus-like secretion into the urethra during arousal.
This secretion helps lubricate the urethra and may help reduce acidity from residual urine.
The glands are not the main producers of semen volume; the seminal vesicles and prostate contribute much more.
Problems can include cysts, blockage, infection, inflammation, or rarely cancer.
Symptoms may include pain, swelling, urinary symptoms, discharge, or blood in semen, depending on the cause.
Not every change in pre-ejaculate or semen points to a bulbourethral gland disorder, so proper evaluation matters.

What are bulbourethral glands?

Bulbourethral glands are small exocrine glands in the male reproductive tract. They sit deep in the pelvis and empty into the spongy urethra through small ducts. Their main job is to secrete a clear, alkaline, mucus-rich fluid during sexual arousal.

In anatomy textbooks, these are often described as paired pea-sized glands. They are part of the accessory sex glands, along with the prostate and seminal vesicles. Accessory glands do not make sperm themselves. Instead, they produce fluids that support sperm transport, protection, and ejaculation.

The NCBI Bookshelf overview of male reproductive physiology and major anatomy references describe bulbourethral glands as part of the system that prepares the urethra for semen passage.

Where are they located?

The bulbourethral glands are located below the prostate and near the membranous urethra, within the deep perineal pouch. Each gland drains via a duct into the proximal portion of the spongy urethra.

That location matters because these glands are closely tied to the urethra, the channel that carries urine and semen out of the body. When the glands release their secretions, the fluid enters the urethra before ejaculation.

Simple location summary

System: Male reproductive tract
Number: Two glands
Position: Inferior to the prostate
Drainage: Into the spongy urethra
Common alternate name: Cowper's glands

What do bulbourethral glands do?

The bulbourethral glands produce a small amount of clear fluid, especially during sexual arousal. This fluid is often discussed in the context of pre-ejaculate or pre-cum, though pre-ejaculate can involve more than one source in the urethral and genital tract.

Main functions of bulbourethral gland secretion

Lubrication of the urethra: The secretion helps coat the urethral lining, which may make semen passage smoother.
Protection from acidity: Residual urine in the urethra can be acidic. The gland's alkaline mucus may help reduce that acidity.
Support for semen transport: By improving the urethral environment, the secretion may indirectly help sperm travel more safely during ejaculation.
Sexual comfort: The fluid may contribute modestly to lubrication during arousal.

Physiology sources such as NCBI's discussion of male reproductive physiology support this role of accessory gland secretions in preparing the urethra and facilitating sperm delivery.

Do bulbourethral glands make sperm?

No. Sperm are made in the testes. Bulbourethral glands make fluid, not sperm cells.

Do they make most of semen?

No. Most semen volume comes from the seminal vesicles, with additional contribution from the prostate. The bulbourethral glands usually contribute a comparatively small amount.

Why they matter in men's health and fertility

Bulbourethral glands are easy to overlook because they are small and rarely discussed outside anatomy or urology. But they still matter for several reasons.

They help create a sperm-friendly pathway: Even a small amount of alkaline, lubricating fluid can help optimize the urethral environment.
They are part of normal sexual function: Their secretion is associated with arousal and urethral lubrication.
They can be involved in symptoms: Pain, infection, blockage, or cysts near the gland or its duct can cause urinary or ejaculatory complaints.
They can affect interpretation of discharge: Clear fluid from the penis may be normal pre-ejaculate, but in some cases discharge can also reflect infection or inflammation.

For fertility specifically, bulbourethral glands are not usually the first place clinicians look when semen analysis is abnormal. Still, anything that alters ejaculation, urethral patency, or the fluid environment sperm pass through can be relevant in selected cases.

Bulbourethral glands and pre-ejaculate

One of the most common search intents around bulbourethral glands is whether they produce pre-ejaculate. The short answer is: yes, they are a key source of the clear fluid released before ejaculation.

Pre-ejaculate is usually a clear, slippery fluid that can appear during arousal. It is commonly associated with the bulbourethral glands, and these glands are often described as producing the fluid that lubricates the urethra before semen passes.

Important clarification

Many people assume pre-ejaculate is always sperm-free. That is not a safe assumption. Research has found that some men can have motile sperm in pre-ejaculatory fluid, while others may not. That means pregnancy can still be possible from exposure to pre-ejaculate.

What normal pre-ejaculate is usually like

Clear or nearly clear
Slippery or mucus-like
Usually small in volume, though this varies
Released during arousal, before ejaculation
Not usually painful

When clear discharge may not be normal

If it has a foul odor
If it is yellow, green, cloudy, or bloody
If it comes with burning, pelvic pain, or fever
If it appears without sexual arousal and is persistent
If there is concern for a sexually transmitted infection

For discharge concerns, trusted sources such as the CDC sexually transmitted infections resources can help explain when symptoms warrant testing.

What's normal vs what's not?

There is no routine "normal range" lab value for bulbourethral gland output the way there is for testosterone or semen volume. Instead, clinicians think in terms of anatomy, function, and symptoms.

Normal vs abnormal bulbourethral gland findings

Usually normal: Small amount of clear lubricating fluid during arousal, no pain, no swelling, no urinary issues
Possibly abnormal: Pelvic pain, painful ejaculation, swelling, recurrent infections, blood in semen, urethral obstruction, painful lump, or ongoing discharge unrelated to arousal

Quick comparison table

Finding	More likely normal	May need medical evaluation
Clear fluid during arousal	Yes	If persistent, painful, or unusual in color
Mild variation in pre-ejaculate volume	Often	If there is sudden major change with symptoms
Pain with ejaculation	No	Yes
Blood in semen	No	Yes
Burning urination with discharge	No	Yes
Perineal lump or swelling	No	Yes

Blood in semen, called hematospermia, is often benign but can occasionally reflect infection, inflammation, stones, cysts, or other urologic issues. The American Academy of Family Physicians review on hematospermia provides a practical overview.

Symptoms and common problems

Most people never know their bulbourethral glands are there. Problems are uncommon, but when they happen, symptoms can overlap with prostatitis, urethritis, pelvic floor pain, or other urinary tract disorders.

Possible symptoms of a bulbourethral gland problem

Pain in the perineum or deep pelvic area
Pain with ejaculation
Discomfort during urination
Urethral discharge
Blood in semen
Recurrent urinary tract symptoms
A palpable cyst or swelling in rare cases
Weak urinary stream or obstruction if a duct cyst is large

Common or recognized conditions involving the bulbourethral glands

Inflammation or infection: Sometimes referred to as Cowperitis in older literature.
Duct cyst or syringocele: A dilation of the bulbourethral gland duct that can cause urinary symptoms or infection.
Obstruction: Blockage of the duct can lead to swelling or cyst formation.
Calculi or stones: Rarely, stones can form in accessory glands or ducts.
Tumors: Very rare, but benign or malignant lesions have been reported.

A syringocele is one of the more searched terms related to this topic. It refers to cystic dilation of the duct of Cowper's gland. Reviews in the urologic literature describe it as a potential cause of lower urinary tract symptoms, infection, hematuria, or post-void dribbling in selected patients.

What can affect the bulbourethral glands?

Several processes can affect these glands or their ducts. Some are mechanical, some inflammatory, and some infectious.

Possible causes and contributing factors

Infection: Bacterial infection involving the urethra or surrounding tissues may extend to the gland or duct.
Inflammation: Noninfectious inflammation can occur as part of broader pelvic or urethral irritation.
Duct obstruction: A blocked duct may lead to fluid buildup and cyst formation.
Congenital abnormalities: Some duct abnormalities are present from birth and become symptomatic later.
Trauma or instrumentation: Urethral procedures, catheterization, or local injury could theoretically contribute in some cases.
Associated urethral conditions: Strictures or chronic urethral irritation may coexist.

Are sexually transmitted infections involved?

They can be. Urethritis caused by infections such as gonorrhea or chlamydia may produce discharge and pain that some people could confuse with a bulbourethral issue. The CDC STI treatment guidelines on urethritis explain common infectious causes of penile discharge and dysuria.

Do lifestyle factors directly damage the bulbourethral glands?

There is not strong evidence that everyday lifestyle factors specifically and directly damage these glands in isolation. However, overall urogenital health can be influenced by hydration, infection risk, safer sex practices, prompt treatment of urinary symptoms, and avoiding unnecessary urethral trauma.

How doctors evaluate bulbourethral gland problems

There is no single routine test for the bulbourethral glands in healthy men. Evaluation depends on the symptom pattern.

Common parts of an evaluation

Medical history: Timing of symptoms, discharge characteristics, urinary issues, sexual history, fertility concerns, prior infections, and any trauma or procedures.
Physical exam: Including genital and sometimes perineal or prostate assessment.
Urinalysis and urine culture: To look for infection or blood.
STI testing: Often appropriate if there is discharge, burning, or new sexual exposure.
Semen evaluation: If fertility or hematospermia is part of the concern.
Imaging: Ultrasound, MRI, urethrography, or cystourethroscopy may be used in selected cases, especially for suspected duct cysts or obstruction.

Testing table

Test or evaluation	What it helps assess	When it may be used
Urinalysis	Infection, blood, inflammation	Burning, pelvic pain, urinary symptoms
Urine culture	Bacterial growth	Suspected urinary infection
NAAT STI testing	Gonorrhea, chlamydia, other infections	Discharge, dysuria, sexual exposure
Semen analysis	Sperm count, motility, semen characteristics	Fertility concerns
Imaging or endoscopy	Cysts, syringocele, obstruction, structural issues	Persistent or unexplained symptoms

If fertility is part of the picture, a semen analysis remains a core test. The World Health Organization laboratory manual for the examination and processing of human semen is the international reference standard for semen testing.

Treatment and management

Treatment depends entirely on the underlying issue. Normal bulbourethral gland function does not need treatment.

If symptoms are due to infection or inflammation

Antibiotics may be used if a bacterial infection is identified or strongly suspected.
Anti-inflammatory treatment may be considered in some cases.
STI-directed therapy is used when testing indicates an infection such as gonorrhea or chlamydia.

If there is a duct cyst or syringocele

Observation may be appropriate if symptoms are minimal.
Endoscopic treatment can be considered when the lesion causes obstruction, recurrent infection, or significant symptoms.
Management is usually guided by a urologist.

If there are fertility concerns

The focus is often broader than the gland itself and may include semen analysis, hormone testing, scrotal exam, varicocele assessment, and evaluation for obstruction or ejaculation disorders.

What not to do

Do not self-diagnose a persistent penile discharge as "just pre-cum."
Do not use leftover antibiotics without a diagnosis.
Do not ignore blood in semen if it recurs or comes with pain or urinary symptoms.

Can bulbourethral gland issues affect fertility?

Usually, bulbourethral gland problems are not a leading cause of male infertility. Most male fertility issues are more directly tied to sperm production, sperm transport, hormonal factors, varicocele, genetic issues, testicular disorders, or broader ejaculatory dysfunction.

That said, the bulbourethral glands can still matter indirectly.

Possible fertility-related effects

Urethral environment: Their alkaline mucus may help create a more favorable passage for sperm.
Ejaculatory comfort: Painful ejaculation can affect sexual function and timing.
Structural obstruction: Rare duct abnormalities or associated urethral issues could potentially disrupt semen passage.
Infection/inflammation: Genitourinary infections can affect reproductive health more broadly.

If you are trying to conceive and also have pain, abnormal discharge, blood in semen, or urinary symptoms, it is reasonable to bring all of that up during a fertility or urology evaluation. Those symptoms may not be the primary cause of infertility, but they are still clinically relevant.

How this differs from semen analysis abnormalities

Abnormal semen parameters such as low sperm count, poor motility, low semen volume, or abnormal morphology usually point clinicians toward the testes, epididymis, vas deferens, seminal vesicles, prostate, hormonal axis, or ejaculation process rather than the bulbourethral glands alone.

Bulbourethral glands vs other male accessory glands

Structure	Main role	Contribution to semen	Key point
Bulbourethral glands (Cowper's glands)	Lubricates urethra, helps neutralize acidity	Small contribution	Associated with pre-ejaculate
Seminal vesicles	Produce fructose-rich seminal fluid	Major contribution	Provide much of semen volume
Prostate	Adds prostatic fluid that supports sperm function	Moderate contribution	Important for semen liquefaction and pH balance
Testes	Produce sperm and testosterone	Not a fluid gland in the same sense	Make sperm cells themselves

Related terms you may see

Cowper's glands: Another name for bulbourethral glands
Cowper's duct: The duct that drains the gland into the urethra
Syringocele: Cystic dilation of the bulbourethral gland duct
Pre-ejaculate: Clear fluid released before ejaculation
Urethritis: Inflammation of the urethra
Hematospermia: Blood in semen
Accessory sex glands: Prostate, seminal vesicles, and bulbourethral glands

Questions to ask your doctor

If you think a symptom might involve the bulbourethral glands, these questions can help make the visit more productive.

Could my symptoms be normal pre-ejaculate, or do they suggest infection or inflammation?
Do I need STI testing, a urine test, or semen analysis?
Could a duct cyst or syringocele be causing my urinary symptoms?
Is blood in my semen something that needs imaging or urology referral?
Could this affect fertility, ejaculation, or sexual function?
What symptoms would make this more urgent?
If treatment is needed, what is the likely cause you are treating?

Frequently asked questions

Do bulbourethral glands produce sperm?

No. They produce a clear lubricating fluid, not sperm. Sperm are made in the testes.

Are bulbourethral glands the same as Cowper's glands?

Yes. Cowper's glands is the older eponym for the bulbourethral glands.

What is the function of the bulbourethral glands?

Their main function is to secrete a clear, mucus-like, usually alkaline fluid that lubricates the urethra and may help neutralize residual acidity before ejaculation.

Is pre-ejaculate always from the bulbourethral glands?

They are a main source, but genital tract secretions can be more complex than a single-source explanation. In everyday use, pre-ejaculate is strongly associated with bulbourethral gland secretion.

Can you get pregnant from pre-ejaculate?

Yes, pregnancy is possible. Some men have sperm in pre-ejaculatory fluid, so pre-ejaculate should not be assumed to be risk-free.

Can bulbourethral gland problems cause pain?

They can. Infection, inflammation, cysts, or duct obstruction may lead to pelvic pain, perineal pain, or painful ejaculation.

Can bulbourethral gland issues lower semen volume?

Usually not in a major way, because these glands contribute only a small portion of total ejaculate volume. Low semen volume is more often linked to issues involving the seminal vesicles, prostate, ejaculation, or partial obstruction.

What is a syringocele?

A syringocele is a dilation of the duct of Cowper's gland. It can sometimes cause urinary symptoms, infection, post-void dribbling, or obstruction.

When should I see a doctor about possible bulbourethral gland symptoms?

Seek medical evaluation if you have persistent discharge, pain with urination or ejaculation, blood in semen, fever, pelvic pain, urinary blockage, or recurring symptoms.