Asparagus Side Effects: Urine Odor, Gas, and More
Health ConditionsDigestive Health

6 Possible Side Effects of Asparagus, Including Gas and Bloating

6 Possible Side Effects of Asparagus, Including Gas and Bloating
Edalin/Getty Images
By
Updated on August 7, 2025
by
Eating asparagus benefits your body in several ways. This vegetable is a good source of antioxidants, fiber, vitamin K, and folate.

But a trip to the bathroom may reveal the side effects of asparagus. Here, learn whether asparagus is hard to digest and if asparagus causes bloating, gas, and smelly urine.

1. Stinky Urine

Why does asparagus make your pee smell? Asparagus contains a chemical compound called asparagusic acid. This acid breaks down into sulfur-containing compounds, which are responsible for a pungent odor when you digest it.

However, only around 20 to 50 percent of people experience strong-smelling urine. Researchers suggest that this is due to differences in how individuals digest food or genetic variations in how people detect certain smells.

Even though it can be a little disarming, it’s completely normal and doesn’t mean anything’s wrong. It’s just your kidneys filtering waste as they’re supposed to.

2. Increased Urination

Asparagus has a component called asparagine, a nonessential amino acid that plays a role in creating proteins. Asparagine can also act as a diuretic, meaning you will likely pee more than usual if you consume it in large amounts.

This can be helpful if you are retaining water due to illness or bloating. But if you are already taking water pills or over-the-counter diuretics, eating a lot of asparagus or other natural diuretics may cause you to lose too much water. This can lead to an imbalance of electrolytes and result in health issues.

Talk to your doctor before taking water pills to determine if you need them. And definitely get in touch with a healthcare professional if you notice that you consistently experience bloating, edema, or other effects of water retention. This could point to an underlying condition.

3. Gas and Bloating

Sometimes asparagus causes gas and bloating.

"While asparagus is a very nutrient-dense food, it may cause gas for some people due to its chemical makeup," says Sarah Schlichter, MPH, RDN. "Asparagus contains natural sugars and oligosaccharides such as raffinose and fructose. These may cause gas in the lower intestine because gas-producing bacteria ferment them."

To reduce gas and bloating from eating asparagus, make sure it's fully cooked. Asparagus is not hard to digest, Schlichter says, but raw vegetables are more likely to cause these symptoms than cooked, softened ones.

"When eaten raw or in excess, asparagus may lead to more temporary bloating and gas," she says.

4. Diarrhea

People who have difficulty digesting the natural sugars in asparagus may experience diarrhea. This isn't the case for everyone though.

Some people are sensitive to foods containing different carbohydrates, including FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols).

 People who are sensitive to FODMAPs may be more likely to get diarrhea after eating asparagus.

If you’re not sensitive to FODMAPs, however, eating asparagus can help reduce diarrhea. When you have diarrhea, eating the tips of cooked asparagus specifically may help.

Schlichter recommends reducing the chances of getting diarrhea from asparagus by drinking plenty of water and eating enough fiber.

5. Other Digestive Symptoms

If eating a few stalks of asparagus gives you stomach pain, you may have an intolerance to fructan, a carbohydrate in asparagus. Because the symptoms are similar to those of gluten sensitivity, doctors often misdiagnose fructan intolerance.

Although wheat and onions are the most common sources of fructan, some other vegetables contain this carbohydrate. If you have trouble digesting fructan, you may experience symptoms like the following:

  • Gas
  • Bloating
  • Belching
  • Constipation
  • Diarrhea
Symptom severity can range being from a mild nuisance to severe enough that you miss work or school.

6. Allergic Reaction

Some people may be sensitive or have an allergy to asparagus.

Immunoglobulin E (IgE) is an antibody produced by your immune system in response to an allergen. At least six compounds are present in raw asparagus that can bind to IgE and cause a reaction, including Aspa o 1, Aspa o 4, and A bet v 1 homologue.

IgE releases chemicals in your cells, causing an allergic reaction that may induce symptoms affecting your skin, throat, nose, or lungs.

While most of the adverse side effects of asparagus are nonthreatening, severe allergic reactions may cause life-threatening anaphylaxis, which requires immediate medical attention. Contact a healthcare professional with urgency if you experience any of the following:

  • Throat, lip, or tongue swelling
  • Breathlessness
  • Hives (urticaria)
  • Swallowing difficulties
  • Rash
  • Belly pain
  • Tight chest
  • Cramps
  • Diarrhea
  • Feelings of dread
  • Vomiting
  • Wheezing

The Takeaway

  • Certain people may experience an unusual odor in their urine after eating asparagus, thanks to asparagusic acid. This is normal and harmless, and not everyone experiences it. Asparagus can also cause bloating, gas, and digestive discomfort.
  • Be cautious if you're consuming larger amounts of asparagus while taking diuretics, as the vegetable has natural diuretic properties and eating it may lead to an imbalance of electrolytes.
  • A rare possibility of an allergic reaction to asparagus exists. Should you experience anaphylaxis symptoms like severe swelling or difficulty breathing, seek immediate medical care.
  • Asparagus is packed with antioxidants, fiber, vitamin K, and folate. Consider gradually introducing asparagus into your diet and thoroughly cooking it to reduce unwanted effects.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. 6 Health Benefits of Asparagus. Cleveland Clinic. September 21, 2023.
  2. Why Does Asparagus Make Your Pee Smell? Cleveland Clinic. February 22, 2021.
  3. Asparagine. National Center for Biotechnology Information. August 23, 2025.
  4. Natural Diuretics to Reduce Water Retention. Cleveland Clinic. November 3, 2021.
  5. Low FODMAP Diet. Cleveland Clinic. February 24, 2022.
  6. Is something in your diet causing diarrhea? Harvard Health Publishing. August 8, 2023.
  7. When you have diarrhea. MedlinePlus. November 6, 2023.
  8. Should you avoid eating fructans? Ohio State University. January 30, 2024.
  9. f261 Asparagus. ThermoFisher Scientific. June 2022.
  10. Immunoglobulin E (IgE) Defined. American Academy of Allergy, Asthma, and Immunology. July 8, 2024.
  11. Anaphylaxis. Cleveland Clinic. October 17, 2023.
Meet Our Experts
See Our Editorial PolicyMeet Our Health Expert Network

Yuying Luo, MD

Medical Reviewer

Yuying Luo, MD, is an assistant professor of medicine at Mount Sinai West and Morningside in New York City. She aims to deliver evidence-based, patient-centered, and holistic care for her patients.

Her clinical and research focus includes patients with disorders of gut-brain interaction such as irritable bowel syndrome and functional dyspepsia; patients with lower gastrointestinal motility (constipation) disorders and defecatory and anorectal disorders (such as dyssynergic defecation); and women’s gastrointestinal health.

She graduated from Harvard with a bachelor's degree in molecular and cellular biology and received her MD from the NYU Grossman School of Medicine. She completed her residency in internal medicine at the Icahn School of Medicine at Mount Sinai, where she was also chief resident. She completed her gastroenterology fellowship at Mount Sinai Hospital and was also chief fellow.

See full bio
Lacey-Muinos-bio

Lacey Muinos

Author
Lacey Muinos is a California-based writer specializing in nutrition, health, wellness, and skin. She received a bachelor's degree in English from California State Polytechnic University. Her work has appeared in a variety of publications and for several brands, such as Health.com, Livestrong, Healthline, Verywell Health, Real Simple, SingleCare, and EltaMD, among others.
See full bio
See Our Editorial PolicyMeet Our Health Expert Network