Green urine is almost always harmless, caused by something you ate, drank, or took as a supplement or medication. In most cases, it clears up within 24 hours once the substance passes through your system. That said, certain infections and rare medical conditions can also turn urine green, so it’s worth understanding the difference.
How Urine Gets Its Color
Normal urine ranges from pale yellow to deep amber depending on how hydrated you are. That yellow comes from a pigment called urochrome, a byproduct of your body breaking down old red blood cells. During that breakdown process, a green pigment called biliverdin is normally converted into a yellow pigment called bilirubin. When something disrupts that conversion, or when you introduce outside substances that carry their own pigments, the usual yellow can shift toward green.
Foods and Supplements That Cause Green Urine
Asparagus is the most well-known culprit. It can give urine a greenish tint along with that distinctive sulfur-like smell often compared to rotting cabbage. Artificially colored foods and drinks, particularly those with blue or green dyes, can also do it. If you drank a brightly colored sports drink, ate frosted cupcakes, or had anything with synthetic food coloring, that’s a likely explanation.
B vitamins are another common cause. Taking a B-complex supplement or a multivitamin with high doses of B vitamins can turn urine a fluorescent yellow-green. This happens because your body absorbs what it needs and flushes the excess through your kidneys. The color change is harmless and simply means you’re excreting the surplus.
Medications That Turn Urine Green
A surprisingly long list of medications can produce green urine. The mechanism varies, but many of these drugs contain chemical structures called phenol groups that, once metabolized by your liver, produce green-tinted byproducts your kidneys filter out. Common examples include:
- Propofol: an anesthetic used during surgeries. Its breakdown products (phenolic metabolites) are excreted through urine and can turn it distinctly green.
- Amitriptyline: an antidepressant.
- Indomethacin: an anti-inflammatory painkiller.
- Cimetidine: a medication that reduces stomach acid.
- Promethazine: used for allergies and nausea.
- Methocarbamol: a muscle relaxant.
- Metoclopramide: used for nausea and digestive issues.
If you recently had surgery or started a new medication and noticed green urine, the drug is very likely the cause. Methylene blue, a medical dye sometimes used in diagnostic tests or compounded into certain medications, can produce a blue-green color that peaks about 2 to 6 hours after you take it and typically remains visible in urine for up to 24 hours.
Infections That Produce Green Urine
Urinary tract infections caused by Pseudomonas bacteria can turn urine green. Pseudomonas produces pigments as part of its metabolism, and those pigments end up in your urine. This type of infection is less common than a standard UTI, but it’s more likely in people with catheters, weakened immune systems, or recent hospital stays.
The key difference between infection-related green urine and a harmless cause is accompanying symptoms. If you also have burning during urination, a frequent urgent need to go, cloudy or foul-smelling urine, lower abdominal pain, or fever, a bacterial infection is a real possibility and needs treatment.
Rare Genetic Conditions
In very rare cases, green urine can signal an inherited enzyme deficiency. One such condition involves a gene called BLVRA, which provides instructions for making an enzyme that converts the green pigment biliverdin into yellow bilirubin. When this enzyme doesn’t work properly, biliverdin accumulates and produces strikingly green urine. These conditions are typically identified in infancy or early childhood, so if you’re an adult noticing green urine for the first time, a genetic cause is extremely unlikely.
How Long Green Urine Lasts
If food, supplements, or a one-time medication caused the color change, your urine should return to its normal shade within about 24 hours. Staying well hydrated can speed things along by diluting the pigments. For ongoing medications, your urine may stay green for as long as you’re taking the drug, which is expected and not a sign of harm.
A simple way to test whether the cause is dietary: think back over the past 12 to 24 hours. Did you eat something brightly colored, take a new vitamin, or start a medication? If so, wait a day and see if it resolves. If the green color persists for more than two days without an obvious explanation, or if it appears alongside pain, fever, or blood, that’s worth a conversation with your doctor.
What the Color Shade Can Tell You
Not all green urine looks the same, and the shade can offer clues. A bright fluorescent yellow-green is the hallmark of B vitamins being flushed out. A deeper, more saturated green often points to medications or dyes. A murky or cloudy green, especially with a strong odor, leans more toward infection. Blue-green specifically suggests methylene blue exposure or certain medications like amitriptyline.
Urine color is just one data point. On its own, green urine rarely signals anything dangerous. Combined with other symptoms like pain, fever, nausea, or changes in how often you urinate, it becomes a more meaningful clue that something else is going on.