Why Does Semen Smell Bad Sometimes?

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Semen does not have a reputation for smelling like a bed of roses.

There’s no denying that it’s a pretty crucial part of life, as a means to transport sperm to fertilise eggs and make new humans – but sometimes, it doesn’t smell so great.

In fact, according to adult store MegaPleasure, one of the most common Google questions related to relationships is: “Why does my husband’s semen smell so bad?”

If you’re worried that you’ve smelt a particularly stinky set of penile discharge, there might just be a reason for it.

Here’s what you need to know.

What is semen supposed to smell like?

It’s hard to explain, but you could try sniffing a pear tree found in North America, the Pyrus calleryana – otherwise known as the “semen tree”.

The comparison stems from the similarity between chemicals released when its flowers bloom and those found in healthy semen.

But if you can’t get close to one of those, US medical outlet Healthline summarises it well: “Semen normally smells like ammonia, bleach or chlorine.”

Made up of 1% semen and 99% other bodily compounds – such as magnesium, calcium, copper, zinc and sulphur – semen is mostly alkaline, so it should be between 7.2 and 8 on the pH scale.

Why might semen smell different occasionally?

Well, pretty much that impact your body’s chemical balance and the substances in semen could change its scent.

Sex

If vaginal penetration takes place, the semen might smell briefly afterwards, because the vagina is more acidic.

Infections

There are several infections which could cause semen to change in scent.

Trichomoniasis is a very common sexually transmitted infection which causes itching and burning as well as producing a foul-smelling discharge from the penis.

Gonorrhea, a sexually-transmitted infection, can also cause burning and the production of white, green or yellow discharge.

As relationship expert Lauren Green told adult store MegaPleasure, “STIs can change the smell of semen, so if there is a change in the smell” both you and your partner “should get it checked out for both your health’s sake.”

Meanwhile prostatitis, a bacterial infection which triggers the inflammation of the prostate gland, can alter the pH and odour of semen.

Tuomas A. Lehtinen via Getty Images

Circumcision

Being uncircumcised could lead to a build-up of sweat, skin and bacteria under the foreskin – sometimes referred to as smegma – which can mix with semen during ejaculation. Sweat and oils still impacts those who are circumcised, but they don’t accumulate to the same levels.

Sweat or urine

These two fluids have high levels of sodium and can be left on the skin after swear or urine dries – that will exacerbate the bleach or chlorine smell in your semen.

It could also continue other substances which then react with the alkaline substances in the semen.

Diet

As explained on the website Very Well Health, eating sweet vegetables, fruits, or spices can improve the taste and smell of semen.

Caffeine, alcohol, cabbage and asparagus though, makes it more bitter, while tobacco can also alter the taste and smell of the semen. Garlic is known for making semen smell particularly pungent, too.

As Green explained: “The foods partner eats will affect the smell and taste of their semen.

“If the smell or taste is different than usual and is off-putting, eliminate any new foods or drinks that they may have added to their diets recently.”

Can you change the semen’s smell?

Yes. Keeping up good personal hygiene habits, particularly washing regularly (including underneath the penis’s foreskin), and keeping up a healthy diet with fruit and vegetables will help it smell better.

Limiting your caffeine and alcohol intake will help, too.

See a doctor if you think the smell continues though, especially if you think it has a rotten odour. They might be able to determine an underlying cause.