Strange Smell After Eating Asparagus? Here's Why That Happens

These tasty spears unleash a stinky problem.

green and purple asparagus stalks on parchment paper on a green picnic table
Photo: Dotdash Meredith

Asparagus is an easy side dish, and it's universally loved. All but one part: Asparagus can make your pee smell funny. There, we said it.

If you've ever sat down to tinkle after eating an asparagus tartine and thought you'd just opened a container of rotten cabbage, you're not alone. Asparagus can turn urine into a odiferous stream. Some people avoid the springtime vegetable entirely due to this stinky caveat.

If you find yourself shying away from asparagus because of the olfactory offense that follows, don't. Enjoy that side of oven-roasted asparagus at your next meal, and just let the stench roll on.

Here, find out why asparagus makes your pee smell and if you can do anything about it.

Why Asparagus Makes Your Pee Smell

This whole stink is the result of a compound called asparagusic acid. The compound, as the name suggests, is found exclusively in asparagus. When the body breaks down asparagus, asparagusic acid metabolizes into several sulfur byproducts.

When you use the restroom, these byproducts rapidly vaporize, and they release the scent of sulfur into the toilet.

"Food, drink, and our body's metabolism can affect the composition of our urine as well as its odor. One of the most common causes of an abnormal urine odor is asparagus," says Kelly Johnson-Arbor, MD, medical toxicologist and co-medical director of the National Capital Poison Center in Washington D.C. "After eating asparagus, many people report having a sulfur-like odor to their urine.

"The cause of this is unknown but may be related to the presence of [volatile organic compounds], including dimethyl sulfoxide, methanethiol, or carbon disulfide, which are present in the urine of people who eat asparagus," Johnson-Arbor adds.

While asparagusic acid is only found in asparagus, other foods produce similar sulfur-rich compounds. These include onions, garlic, Brussels sprouts, and even coffee.

This Baked Feta Pasta Uses Asparagus and Lemon for a Perfect Spring Twist

How Long Does Asparagus Make Your Pee Smell?

The body begins absorbing and breaking down asparagusic acid quickly—within 15 minutes of your first bite. So your next trip to the bathroom post-meal could be quite smelly.

How long the asparagus pee smell will last is variable. One study found that the smell's half-life (or the halfway point of how long the aroma will last) is 4.7 hours. That means you could have an odor for about nine hours after eating. But another study found the half-life was 7.2 hours, which means a smell could linger for up to 14 hours.

Either way, the smell won't last more than a day. If it does linger, it might not be because you ate some asparagus spears. It could be a sign of an infection or other issues, and you should consult your doctor.

asparagus spears sorted by size
Courtney West/Southern Living

Does Asparagus Make Everyone's Pee Stink?

It's unclear if asparagus has this smelly effect on every one. As you might imagine, there are more pressing medical issues to be studied.

But one study asked nearly 7,000 people if they sensed a stench after eating asparagus, and it found that 58 percent of men and about 62 percent of women did.

However, it is possible some people think asparagus spears spare them the pungent problem, when in fact they just can't smell the odor. That same study of 7,000 people found genetic variations in olfactory receptors (that is, things in your nose that translate smells to your brain) may account for who can and cannot smell the sulfur-producing compounds released by eating asparagus.

"Interestingly, some individuals are unable to smell the pungent urine odor associated with asparagus consumption," according to Johnson-Arbor.

Each person may describe the odor differently, but most will use words like cabbage, Brussel sprouts, or rotten eggs. Those are all related to the smell of sulfur.

How To Get Rid Of Smelly Urine

You can't. If your body produces these compounds when you eat asparagus, you can't stop it. But it's completely normal, so you shouldn't be worried or even embarrassed.

Also, asparagus is a healthy and tasty ingredient for soups, salads, quiches, and more, so you wouldn't want to skip it just because of the pee problem.

Go ahead and enjoy your Creamy Asparagus Soup. The bathroom bouquet will end soon enough.

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  2. Bhattacharjee P, Singhal RS. Asparagus: production, quality, and processing. In: Siddiq M, Uebersax MA, eds. Handbook of Vegetables and Vegetable Processing. Chichester, UK: John Wiley & Sons, Ltd; 2018:493-508. doi:10.1002/9781119098935.ch21

  3. Specialists in Gastroenterology, St. Louis, MO. Low sulfur diet.

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  6. Facius A, Atkinson LA, Hanna K, Coombes MC, Lahu G, Wagner JA. What can be learned from crowdsourced population asparagus urinary odor kinetics? CPT Pharmacometrics Syst Pharmacol. 2019;8(6):407-414. doi:10.1002/psp4.12401

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