healthHealth and Medicine

Where Does Sperm Go After Vasectomy?


Rachael Funnell


Rachael Funnell

Writer & Senior Digital Producer

Rachael is a writer and digital content producer at IFLScience with a Zoology degree from the University of Southampton, UK, and a nose for novelty animal stories.

Writer & Senior Digital Producer

Where does sperm go after vasectomy

Vasectomy effectively blocks sperms' exit but it won't result in a build up. Image credit: Anicka S /

There are many ways to prevent sex from resulting in a pregnancy. One method is a vasectomy, where surgical changes are made to the male reproductive system to block the release of sperm during ejaculation. While the exit is effectively boarded up, the testicles go on producing the goods, which got us wondering: where does sperm go after vasectomy?

The answer taps into the resourceful physiology of the testicle (the organ within the human body most similar to the brain, didn't ya know?) which acts as a sort of recycling plant for sperm.


These gametes (sex cells) are first produced by stem cells that line tiny, hose-like structures called seminiferous tubules. There can be around 900 of these per testis, and each has a wall and central space called a lumen.

Once the stem cells have created a sperm cell – a process called spermatogenesis – it needs around 65-75 days to mature in the wall of the seminiferous tubule. Once it’s good to go on to the next stage, it enters the lumen and moves into the epididymis.

Here, sperm cells sit in a small but loooong tube called the epididymis (which could stretch to around 20 feet outside of the body) where they become fully mature and perfect their swimming skills. Once ready, they shuffle on down to the vas deferens, effectively the ejector tunnel of the testis.

This muscular tube connects the testis to the urethra (pee hole) so that when ejaculation occurs they can exit the body, a journey made smoother by a mixture of secretions from the prostate gland and seminal vesicles to make a motile fluid.

What happens in a vasectomy?

As to where a vasectomy happens – the clue is in the title. A vasectomy involves blocking off the vas deferens, which sperm need to exit in order to join the semen and leave the body.

Around 12 weeks after a vasectomy, all sperm should be cleared from this tube, meaning that future ejaculations will be made up of sterile (in the reproductive sense of the word) fluid. Someone who’s had a vasectomy likely won’t be able to detect any changes in their semen, as the missing ingredient is just four to five micrometers long and two to three micrometers wide.

Where does sperm go after vasectomy?

What happens if someone’s had a vasectomy is similar to what happens if ejaculation doesn’t occur. Testicles are like recycling plants, and if sperm aren’t ejaculated, they can be broken down for parts and reabsorbed. This removal of sperm that’s past its prime is a vital process as it ensures that sperm leaving the body is in tip top condition should it need to embark on a long race to the egg.

This process is why the term “blue balls” – also known as epididymal hypertension – has nothing to do with sperm. It’s true that the human testis produces an incredible amount of sperm: roughly 300 million sperm cells a day, equating to 12.5 million per hour or 3,500 a second. However, any unused goods are broken down and removed, meaning sperm can’t exceed capacity within the testis.


While testicles won’t swell up from a sperm overload, the other secretions which make up the semen recipe can build up, causing discomfort if sexual arousal doesn’t result in ejaculation. However, the condition is never a reason to put pressure on penetrative sex as it can easily be resolved by oneself.


[H/T: Science Focus]


healthHealth and Medicine
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