Lime green pee is almost always caused by something you ate, drank, or took as a supplement or medication. It looks alarming, but in most cases it’s harmless and temporary. The color comes from pigments or dyes that your kidneys filter out of your blood and concentrate in urine, where they become much more visible.
Foods and Supplements That Turn Urine Green
Brightly colored food dyes are one of the most common culprits. Foods and drinks containing blue or green artificial dyes (think green sports drinks, lime-flavored candies, or frosted cupcakes) can tint your urine green within hours. The effect is more dramatic when you’re well-hydrated, because dilute urine lets the dye color show through more clearly. It typically clears up within a day or two after you stop consuming the dye.
Chlorophyll supplements are another frequent cause. Chlorophyll, the pigment that makes plants green, is sold as a liquid supplement and in tablet form. When taken orally, it can cause green discoloration of both urine and stool. This is a well-documented and completely benign side effect. If you recently started a “liquid chlorophyll” trend from social media, that’s very likely your answer.
Asparagus can occasionally give urine a greenish tint, though it’s better known for the distinctive smell it produces. The green color comes from plant pigments that pass through your system largely intact.
Medications That Cause Green Urine
A surprisingly long list of medications can turn urine green. The color change happens because the drug itself, or a byproduct your liver creates while breaking it down, carries a blue or green pigment that gets excreted through the kidneys.
Medications linked to green urine include the anesthetic propofol (used in hospitals during sedation), the antidepressant amitriptyline, the anti-nausea drug promethazine, the anti-inflammatory indomethacin, and the stomach acid reducer cimetidine. Propofol is a particularly well-known cause, though it affects fewer than 1% of patients who receive it. In reported cases, urine turned green within hours of starting the drug and returned to normal once it was stopped.
Methylene blue, a dye used in certain medical tests and to treat a blood condition where oxygen delivery is impaired, reliably turns urine blue or blue-green. If you’ve had a recent medical procedure involving any kind of dye injection, that’s a strong possibility.
If you started a new medication in the past few days and noticed the color change, check the side effects list on the packaging or call your pharmacist. Green urine from medication is not dangerous on its own and resolves once the drug leaves your system.
Urinary Tract Infections
Certain bacterial infections can produce green pigments in the urinary tract. The bacterium Pseudomonas aeruginosa is the classic example. It produces a blue-green pigment as a natural byproduct of its metabolism, and when it infects the urinary tract, that pigment can visibly tint the urine. This is more common in people with catheters or in hospital settings than in otherwise healthy adults.
The key difference between an infection and a harmless cause is the presence of other symptoms. If your green urine comes with burning during urination, a strong or foul odor, cloudy appearance, fever, or pain in your lower back or sides, an infection is more likely and worth getting checked out promptly.
Bile Pigment Problems
Your liver produces a green pigment called biliverdin as part of the normal process of breaking down old red blood cells. Normally, biliverdin gets converted into bilirubin (which is yellow-orange) and excreted through bile into your intestines. But when something disrupts that process, biliverdin can build up and spill into your urine, turning it green.
This can happen with biliary obstruction (a blocked bile duct), significant liver disease, or liver failure. A rare genetic condition called hyperbiliverdinemia causes elevated biliverdin levels that can turn urine, skin, and even the whites of the eyes green. These causes are uncommon, and they come with other noticeable symptoms like jaundice, pale stools, abdominal pain, or general illness. Isolated green urine with no other symptoms is very unlikely to signal a liver problem.
What About B Vitamins?
B vitamins are famous for changing urine color, but they typically make it bright or neon yellow, not green. Riboflavin (vitamin B2) in particular turns urine a vivid fluorescent yellow when you take more than your body needs. If your urine looks more yellow-green than true green, a B-complex supplement or multivitamin could be mixing with your natural urine color to create that lime shade. This is harmless and just means your body is excreting the excess.
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 food coloring? Start a new supplement? Begin a new medication? In the vast majority of cases, the answer is sitting in your kitchen or medicine cabinet.
If you can identify a likely food or supplement, try eliminating it for a day or two. Green urine from dietary causes typically resolves within 24 to 48 hours once you stop consuming the source. Medication-related color changes resolve once the drug clears your system, which varies by the specific medication but is often a matter of hours to days.
If the green color persists for more than a few days with no obvious dietary or medication explanation, or if it comes alongside pain, fever, nausea, or changes in how often you urinate, it’s worth getting a urine test to rule out infection or a metabolic issue. A simple urinalysis can quickly identify bacteria, abnormal pigments, or other markers that point to a specific cause.