What Is Semen Made Of And Where Does It Come From?
Have you ever been late-night googling and found yourself in a Google hole? Let’s say you start googling Kylie Jenner, then you fall into looking at information about her and Travis Scott. That leads you to their baby, Stormi, which reminds you of Stormy Daniels, which makes you google Stormy Daniels’ affair with Trump. Then you start to wonder how old Trump was when he had the affair. This gets you wondering how the male reproductive system works into old age, which makes you google: How does semen work and what is it made of?
Well, if you’ve reached our page due to an extensive late-night Google binge: Welcome; we’re glad you’re here. And we won’t bore you with any more filler about Stormy Daniels. Instead, we’ll get to the real reason you’re here: to find out about this alien-like substance that squirts out of half of the population’s genitals.
So let’s dive right in and talk about what the heck semen is, where it comes from, and what it’s made of.
What is Semen?
Let’s start with the basics: Semen and sperm are not the same thing.
Sperm is just one of the many components of semen, though, arguably the most vital. The other elements are there to help aid the sperm in getting to its end goal: an egg. These other parts help the sperm by assisting with its mobility, lubrication, and even reducing the resistance of the egg to the sperm (yes, eggs fight against the sperm).
A typical male can produce anywhere from 2 – 6 mL of semen when ejaculating. For comparison, a US teaspoon is about 5 mL, so a guy’s jazz can be about half or a little more than the amount of vanilla extract you put into cookies. *Disclaimer: We don’t advise adding this secret ingredient to cookies of any kind*
Where does Semen Come From?
Semen comes from the genitals of men. Not specific enough for you? Then let’s get into the nitty-gritty.
It all starts with sperm. Sperm is produced by the testes and is stored in the epididymis. Think of the epididymis as a reservoir in the back of the testicles. From this reservoir, the sperm travels upstream (through the vas deferens) with its eyes set on the ejaculatory ducts where it will be ready for launch.
As the sperm travels through the vas deferens, it encounters some pretty steep hills and realizes it can’t make it by itself. That’s where the little guy’s friends come in. Other parts of the reproductive system see the sperm struggling, so they mix in their fluids to help it reach its goal. These fluids come from the seminal vesicles, the prostate, and the bulbourethral glands.
Components of Semen
Now that you know the basic elements of semen, you might be wondering what fluid comes from where, and what’s the makeup of these fluid components. Don’t worry, dear reader! We’ve got you covered on all the seminal organ elements.
Sperm comes from the testicles and accounts for ~2-5% of all semen. While this may not seem like a lot, there are 20 – 100 million little spermies per mL of ejaculate. And because men produce anywhere from 2 – 6 mL of semen, some can shoot out 600 million spermatozoa in one single ejaculation! #Yikes
*Fun Fact* Some like it hot, but sperm likes it cold. About 2-3 degrees cooler than the body’s temperature, that is. Sperm thrives in colder environments and the testicles provide that. It’s true; testes don’t hang outside of the body for pure aesthetics (lol), they actually hang because they need to stay cool. Take a note from this pair if you’re ever looking for pointers on how to hang out and chill.
The seminal vesicles are a pair of coiled glands located below the bladder and next to the vas deferens. This is where the bulk of the semen comes from– about 70% to be exact.
The fluid that comes out of the vesicles contains proteins, ascorbic acid, amino acids, phosphorus, potassium, l-carnitine, among other nutrients. But it’s mainly made up of fructose, or broken-down sugar, which provides sperm with the energy needed to travel upstream.
*Fun Fact* The female body views sperm as a foreign agent and actively works to reject it. Fluid from the seminal vesicles contains prostaglandins which help the sperm sneak in undetected. Creepy, right?
The prostate gland is located beneath the bladder and in front of the rectum. About 25% of semen is made up of liquid produced by the prostate.
Fluid that emerges from the prostate is made up of acid phosphate, citric acid, calcium, zinc, and magnesium. Of these, zinc is the most prolific and the most vital, as it helps stabilize the sperm’s DNA. This is also where semen gets its color and taste.
*Fun Fact* The prostate also produces a fluid called prostatic specific antigen. This liquifies the semen and allows the sperm to swim freely.
The remaining <1% of semen comes from the bulbourethral glands. These babies sit near the base of the penis and are about the size of a pea.
When a man is sexually aroused, the glands secrete a mucus which lubricates the penis head, neutralizes the acidity of the vagina, and eliminates any leftover urine from the urethra. Basically, its job is to make sure everything runs smoothly.
*Fun Fact* The secretion from these glands are typically what is referred to as “pre-cum,” and contains no sperm! However, if a man has recently ejaculated, the pre-cum can sometimes pick up and carry out leftover sperm, so keep that in mind.
Talk About a Load of Information!
Wow. A lot goes into those 5 seconds of ecstasy. Who knew that the reproductive system was working so hard just to produce a teaspoon’s worth of baby gravy. Now the next time you, your partner, or anyone who has a weiner ejaculates, you can tell them that you know all about it.
To think, this all started because of a Google search for Kylie Jenner. And if you’re interested in continuing down this rabbit hole of information, check out our Benefits of Semen post to learn how all of these components come together to provide benefits for your body. We break it down into easy-to-swallow chunks.
While you’re here, be sure to get that man milk tested for STDs. Just because you know where it comes from, doesn’t mean you know where it’s been.
Medically Reviewed by J. Frank Martin JR., MD on October 1, 2018
Author: Lauren Crain
Lauren Crain is a writer, designer, and joke-teller. With an academic background from Texas State University in communication and education, Lauren works tirelessly to find the best way to transform hard-to-grasp concepts into straightforward information. She's been a writer her whole life, but she began writing professionally in 2014. In 2018, she joined the STDcheck.com editorial staff because of her passion for communicating information about public health and destigmatizing sexual health. Before becoming a member of the STDcheck.com team, Lauren worked as a communication skills teacher, marketing coordinator, and freelance writer and designer. Her work has been featured on Forbes, The Muse, Insider, Clutch.co, Her Campus, and Business News Daily. When she's not researching, writing, or trying to communicate authentically, you can find her sitting outside.