Semen

What is semen?

Semen (SEE-men) is a thick, sticky, whitish-gray fluid of the male reproductive system. It typically contains sperm. But it also has components that help nourish sperm and fluids that make it easier to deposit sperm toward the back of the vagina and fertilize an egg (conception).

Other names for semen include:

• Seminal fluid.
• Ejaculate.
• Cum.

What does semen do?

Semen helps transport sperm out of your body and into the female reproductive system to help fertilize an egg and start the fetal development process.

When does semen come out?

Semen comes out from a penis, usually after orgasm (ejaculation). But semen can release without experiencing an orgasm (anorgasmia or ejaculatory anhedonia).

Where is semen produced?

Your seminal vesicles and prostate gland make a whitish fluid that mixes with sperm from your testicles to produce semen.

Semen contains approximately:

• 65% to 75% fluid from your seminal vesicles.
• 25% to 30% fluid from your prostate.
• 1% to 5% sperm.

Where is semen stored?

A tube at the back of your testicle (epididymis) stores sperm until it matures. Your sperm then combines with seminal vesicle fluid and prostate fluid to create semen.

What is semen made of?

Semen mainly consists of:

• Water.
• Mucus (a type of lubricating substance — not the same as nasal mucus).
• Plasma.

It also contains small amounts of:

• Calcium.
• Citrate.
• Fructose.
• Glucose.
• Lactic acid.
• Magnesium.
• Potassium.
• Zinc.

These nutrients help nourish your sperm and give them the energy they need to swim.

What are common conditions that affect semen?

Some conditions that involve semen include:

• Sexually transmitted infections (STIs). You can get many different STIs from semen, including human papillomavirus (HPV), herpes simplex, gonorrhea, human immunodeficiency virus (HIV) and more.
• Pyospermia. Pyospermia is when there are a high number of white blood cells in your semen. Common causes include infections, STIs and inflammation in your urethra (urethritis) or prostate (prostatitis).
• Retrograde ejaculation. Retrograde ejaculation is when semen travels backward into your bladder instead of your penis when you orgasm.
• Semen allergy. This is a rare allergic reaction to the proteins in semen.

What are common signs or symptoms that affect semen?

Symptoms that affect semen include:

• Yellow semen. Temporary causes may give your semen a yellow hue, including eating certain foods, smoking or taking certain medicines or supplements. Jaundice and infections can also turn your semen yellow. Your semen may also get yellowish as you age.
• Blood in your semen (hematospermia). Several conditions may cause blood to appear in your semen, including a blood vessel bursting during ejaculation, recent surgery in the area, an injury to your genitals or certain STIs.
• Low ejaculate volume. Some causes of low ejaculate volume may include an obstruction (blockage), retrograde ejaculation and hormonal imbalances.

What are common tests to check the health of semen?

A semen analysis is the most common semen test. A semen analysis:

• Measures how much semen you produce and its quality.
• Examines the health and quantity of your sperm.
• Looks for the presence of white blood cells and signs of inflammation in your genital tract.

How can I improve semen quality?

Semen volume and texture vary from one person to another. The following may improve your semen and sperm quality:

• Quitting smoking.
• Limiting your alcohol consumption.
• Following eating patterns that incorporate lots of fruits and veggies.
• Maintaining a healthy weight for you.
• Increasing your physical activity.
• Using protection — including condoms, female condoms and dental dams — during sexual intercourse to help protect yourself from STIs.

Talk to a healthcare provider before you make any changes to your lifestyle or habits.

Are semen and sperm the same?

No, they aren’t the same. Sperm helps make up semen. Semen consists of sperm, seminal vesicle fluid and prostate fluid.

How much sperm is in semen?

It depends. A typical sperm count may range from 15 million to more than 200 million per milliliter of semen. But you may have less than 15 million sperm (oligospermia) or no sperm in your semen (azoospermia).

At what age does a man stop ejaculating?

Many people may see a reduction in their sexual activity and sex drive (libido) as they get older. But there’s no specific age at which you stop ejaculating — it varies from person to person. Some people may have difficulty ejaculating in their 30s, while others continue to ejaculate into their 80s.

Talk to a healthcare provider if you have any questions about your sexual health. They’ll assess many different factors that may affect your ability to ejaculate, including your overall health, eating patterns, stress levels and other health conditions.

Is precum semen?

No, pre-ejaculate (precum) isn’t semen. Pre-ejaculate is a clear lubricant that comes out of your erect penis before you orgasm. It makes it easier for sperm to travel outside of your body and through the female reproductive tract.

Pre-ejaculate usually doesn’t contain sperm. But if you already have sperm in your urethra (like if you ejaculated earlier and didn’t clear out your urethra by peeing after), sperm may mix with the pre-ejaculate. Therefore, pregnancy is possible if pre-ejaculate enters the vagina.

A note from Cleveland Clinic

You may not think too much about semen unless you notice any changes in its color or if you and your partner have problems getting pregnant. But it’s important to talk to a healthcare provider about any semen changes or fertility difficulties. They’ll order tests to analyze your semen, which include examining how much semen you produce, how many healthy sperm are present and whether there are any signs of problems. Meanwhile, you can help ensure your semen helps transport, protect and nourish your sperm by quitting smoking, drinking alcohol in moderation and protecting yourself from STIs.