The Guide to Getting It On (13 page)

End of Chapter Thanks
to Richard Wassersug, University of British Columbia, Terri Fisher, The Ohio State University at Mansfield, Marian Dunn, SUNY Downstate Medical Center, Dr. Stephanie Buehler, Newport Beach, California, and Dr. David Ley, Albuquerque, New Mexico.

CHAPTER

6

Semen Confidential

A
woman from Utah asked, “Why does male ejaculate smell vaguely of cleaning products?” It’s funny how one question can lead to an entire chapter—about semen, not cleaning products. In addition to the bleach-like smell, this chapter looks at semen stains, semen allergies, upset stomachs after swallowing semen, why semen gets clumpy in water and sticks to hair on the shower drain, and finally, the answer to a question a reader submitted several years ago: “Why does my boyfriend’s jizz burn when it gets in my eye?”

Lock and Load

Semen doesn’t pour out of a penis fully homogenized like milk from a carton, even if a guy has been bouncing on a trampoline. The first squirt has secretions from the Cowper (bulbourethral) and Littre glands. The prostate gland manufactures the next wave of man chowder, which is 15% to 30% of the total volume of each ejaculation. This is followed by the relatively small but potent contribution of sperm from the testicles. The seminal vesicles hold up the rear with the biggest blast of all, producing 65% to 80% of the entire wad. This adds up to a total volume of almost a teaspoon for an average ejaculation.

Why Semen Smells Like Clorox

When Ms. Utah asked why male ejaculate smells “vaguely of cleaning products,” we assume she is referring to a bleach-like smell, unless semen in Utah smells like Windex, 409, or Janitor in a Drum.

As mentioned above, the lion’s share of semen is made by the seminal vesicles and prostate gland which reside inside the male pelvis. (For more on the prostate, see Chapter 18:
The Prostate and Male Pelvic Underground.
) Less than 5% of semen is made by the testicles. So which of these cause semen to have a bleach-like smell?

After performing countless biopsies of testicles, urologists know that sperm and testicular fluid are odorless. So we can rule out the testicles. The seminal vesicles aren’t the culprit, either. If you guessed the prostate gland, you are correct. The prostate produces a chemical called spermine, which gives semen its characteristic cleaning-product smell. Spermine is a member of the polyamine family of chemicals. (Semen also smells like fresh bean sprouts, which makes perfectly good sense because although bean sprouts don’t have prostate glands, they do contain the chemical spermine just like semen does.)

Changes in the pH of semen and variations in how the body buffers it explain why some men’s ejaculate smells more bleachy than others, or why one guy might smell like Clorox one day and Lysol the next. That’s because pH impacts how spermine behaves.

For science and history buffs, spermine phosphate crystals were first found in semen in 1678 by Anton von Leeuwenhoek, father of the modern microscope and the first microbiologist. It appears that semen was one of the things Leeuwenhoek looked at under his new microscope. Two hundred years later, German chemists gave spermine its name, although women since the time of Aristotle have known about the cleaning-product smell.

As a man is about to ejaculate, the various components that make up semen collect in the urethra which runs through the prostate. To create an ejaculation, the muscle fibers surrounding this part of the urethra then squeeze it like you might the bulb of a turkey baster. At some point during the collection and ejaculation process, the phosphate in the spermine-phosphate molecules gets pried off. This allows the free base of spermine to be released which creates the chlorine bleach-like smell. However, semen stops smelling like bleach after it’s been in the air for a while because the free bases in spermine start linking together to form an odorless compound.

When A Penis Spits in Your Eye

A few years ago, a reader asked why her boyfriend’s ejaculate burns so much when it gets in her eye. We had given up on ever knowing why after receiving a particularly curt and nasty response from an optometry professor at a leading university. Due to the nature of the question, he apparently thought we were trolls. Fortunately, an answer has finally emerged and it, too, points to spermine.

While the concentration of spermine in semen isn’t nearly as high as when you order it from a chemical supply house, pure spermine carries some seriously harsh warnings. The material safety data sheet for it says:

Danger!
Corrosive. Causes eye and skin burns. May cause severe respiratory-tract irritation with possible burns. May cause severe digestive-tract irritation with possible burns. May cause central- nervous-system effects. May cause cardiac disturbances. Causes eye burns. May cause chemical conjunctivitis and corneal damage. Causes skin burns.

While there might be other chemicals in semen that cause your eyes to burn, the number one culprit on anyone’s list should be spermine. Also, semen can be a bit alkaline, which could possibly cause eyeball irritation.

Why an Upset Stomach?

Some women report getting a stomach ache after swallowing their lover’s splooge. This is usually blamed on the prostaglandins that are in semen, which might make it similar to the kind of stomach upset that some people get after taking aspirin. However, after reading spermine’s material safety data sheet, you can’t help but wonder if spermine is involved as well.

What Makes Boy Batter Taste Like It Does

A thorough explanation of why male ejaculate tastes the way it does is beyond the scope of this book, and probably beyond that of any other. However, in looking at the chemicals in semen, the amount of citrate ions stick out as possible culprits. These ions help semen to be a strong buffering agent; they also make for a lot of calcium citrate, which tastes both salty and sour.

Semen has a number of other ions, namely magnesium, potassium, sodium, and zinc. As for how zinc tastes, there’s a fairly well-known taste test that’s used to determine if people have low levels of zinc. You are given a solution of zinc to drink, and if you can’t taste anything, it’s because your body has a zinc deficiency. However, if you’ve got an acceptable level of zinc, the zinc solution tastes “strong and unpleasant.” This might indicate that semen would taste better to people who have a zinc deficiency, although it’s probably not wise to phone your healthcare provider and say, “My boyfriend’s cum tastes really yummy to me. Does this mean I’m zinc-deficient?” Let’s just say there’s a fair amount of zinc in spunk, and zinc doesn’t taste very good unless you have a zinc deficiency or the semen is low in zinc. Ditto for magnesium, and we all know what sodium tastes like.

On the good side, semen does contain fructose and glucose. However, in their “Review of the Physical and Chemical Properties of Human Semen,” Owen and Katz discovered that the amount of fructose and glucose can vary as much as four-fold from man to man.

Semen is home to low concentrations of other polyamines by the names of putrescine and cadaverine. These compounds are essential for cells to live. They also like to announce themselves when cells die. Both putrescine and cadaverine are well-named and are responsible for the rotting flesh smell that things produce soon after they die. This familiar smell is an important indicator of spoilage in food.

Most cheeses that are really smelly and sharp-tasting are high in putrescine, but so is fermented soy sauce, shrimp, and certain citrus fruits. Putrescine and cadaverine are what bring us the fishy smell when women have bacterial infections in their vaginas. One reason why semen doesn’t ordinarily smell fishy is because it has a very low concentration of cellular matter, so there are fewer dying cells to produce a fishy odor.

When Semen Smells Bad Rather than Just Bleachy

After being with a couple of men, most women have a baseline sense of what semen normally smells like. However, semen occasionally has an extra pungent odor that our andrology-urology consultant says can be the result of a hidden prostate infection. He’s referring to a combined bleach-like and fishy odor. The fishy part comes from the polyamines that are released from decaying white blood cells that end up in the semen as a result of the infection in the prostate.

Semen normally has some white blood cells in it, but at a very low level. When a man has a prostate infection, the white blood cell count in his semen increases, which results in more polyamines like putrescine being liberated:

“Since I do a lot of semen analysis in my office, I can tell the semen that has lots of white blood cells when we open the container. It has a really strong, bad odor—to the point that my research assistant is able to suspect that men have infection just from the odor of semen when we are preparing slides to be examined.”

Men who have prostatitis might notice yellowish, jellylike globs in their semen. Suspicions also rise when semen has a honey-like sweet smell. This can be the result of a staph infection. Healthy man-jam tends to be mostly white and has the smell of clean, fresh bleach.

Out, Damn Spot

Ever notice that some boys’ semen stains are worse than others? Semen contains a lot of protein, much of which is albumin. This is the same kind of protein that is in egg whites, although we don’t recommend baking with it.

As protein dries it changes optical qualities and color. The yellowish staining ability of semen is related to the concentration of protein in it. The concentration of sperm can also have an impact. The higher the sperm count, the more opaque or yellowish semen will be. These factors determine why one guy’s semen may have a greater tendency to leave yellowish stains in underwear and sheets than another guy’s semen.

How Thick is Splooge?

Viscosity is a measure of how fast or slow a liquid flows from a container. The viscosity of male ejaculate fresh from the penis can vary from 1.3 cP to 23.3 cP at room temperature. For reference, the viscosity of water is around 1.0 cP. Given such a wide range, this means some men’s wads are almost as thin as water while others nearly need a grease gun to get it out. (Some women cite the texture of semen as being the reason for why they don’t like to swallow when giving blow jobs. They might have better luck with another man.)

The viscosity of semen starts to change as soon as it is ejaculated. That’s because during ejaculation, a protein called prostate-specific antigen (PSA) which is made by the prostate gland mixes with the rest of the semen. This starts a reaction that makes semen become more watery so sperm can swim in it. As a testament to how well PSA does its job, if a man ejaculates in a glass his semen will become almost like water within 5 to 30 minutes. This liquefaction happens even faster when semen is in the vagina, and it’s why semen drips out of a woman’s vagina when she stands up after intercourse.