Green urine is almost always caused by something you ate, drank, or a medication you’re taking. It looks alarming, but in most cases it’s harmless and temporary. Less commonly, green urine can signal a urinary tract infection or a problem with bile flow from the liver, so the context around the color change matters.
Foods and Supplements That Turn Urine Green
The most common culprit is something in your diet. Asparagus sometimes gives urine a greenish tint, along with that distinctive smell often compared to rotting cabbage. Foods and drinks containing artificial dyes, particularly blue or green food coloring, can do the same. When blue dye mixes with the natural yellow of urine, the result looks green. Think brightly colored sports drinks, candy, frosting, or novelty beverages.
B vitamins are another frequent cause. They can turn urine a fluorescent yellow-green that’s especially noticeable if you’ve recently started a new multivitamin or B-complex supplement. Chlorophyll supplements, popular as a “detox” product, also produce green urine because the pigment passes through your kidneys largely intact.
If food or supplements are the cause, you’ll typically notice the color shift within a few hours of eating or drinking the item, and it clears up within a day or two once you stop consuming it. Staying well hydrated speeds the process along by diluting the pigment.
Medications That Cause Green Urine
Several prescription and over-the-counter drugs are known to change urine color to green or greenish-blue. The most well-documented include:
- Amitriptyline: a medication used for depression and chronic pain
- Indomethacin: an anti-inflammatory drug used for arthritis and gout
- Cimetidine (Tagamet HB): used for ulcers and acid reflux
- Triamterene (Dyrenium): a water pill used for high blood pressure or fluid retention
- Propofol (Diprivan): an anesthetic used before surgery or in intensive care settings
These medications or their breakdown products happen to absorb light in a way that produces a blue or green tint once they’re filtered through the kidneys. The effect is harmless and doesn’t mean the drug is causing damage. If you recently started a new medication and notice green urine with no other symptoms, the medication is very likely the explanation. The color returns to normal once the drug is out of your system.
Urinary Tract Infections
Certain bacteria that infect the urinary tract produce pigments as they multiply, and some of those pigments are green. Pseudomonas species are the most common example. These infections are more typical in hospital settings or in people with catheters, but they can happen to anyone.
The key difference from a food or medication cause is that a bacterial infection comes with other symptoms: burning or pain during urination, a frequent urgent need to go, cloudy or foul-smelling urine, and sometimes fever or lower abdominal discomfort. If you have green urine paired with any of these symptoms, it’s worth getting a urine test. A simple urinalysis can detect bacteria and white blood cells that confirm an infection.
Liver and Bile Flow Problems
This is the least common but most serious potential cause. Your liver produces a greenish pigment called biliverdin as part of the normal process of breaking down old red blood cells. Usually, biliverdin is converted to bilirubin (which is yellow-orange) and excreted through bile into your intestines. But when bile flow from the liver is blocked or slowed, a condition called cholestasis, biliverdin can build up and spill into the bloodstream and eventually into urine.
Gallstones are one cause of blocked bile flow. Severe liver disease is another. A rare genetic condition called hyperbiliverdinemia causes elevated biliverdin levels that can turn urine, skin, and even the whites of the eyes green. These liver-related causes produce other noticeable symptoms well before green urine shows up: yellowing of the skin or eyes (jaundice that may take on a greenish cast), pale or clay-colored stools, dark urine that may shift between brown and green, itching, abdominal pain on the right side, fatigue, and nausea.
If green urine appears alongside any of those symptoms, it points to something that needs medical evaluation promptly. Blood tests measuring liver function and imaging of the bile ducts can identify the underlying problem.
How to Figure Out Your Cause
Start with the simplest explanation. Think back over the past 24 to 48 hours: did you eat or drink anything with bright artificial coloring? Start a new supplement? Begin a new medication? If yes, that’s almost certainly your answer. Stop the suspected item and watch whether the color returns to normal within a day or two.
If you can’t connect the color change to anything you’ve consumed, pay attention to other signals from your body. Green urine with no other symptoms and no obvious dietary trigger is still unlikely to be dangerous, but it’s reasonable to mention it at your next medical visit. Green urine with pain, fever, nausea, or changes in stool color is a different situation and warrants a call to your doctor sooner rather than later. A basic urine test and blood panel can rule out infection and liver issues quickly.