Greenish-yellow urine is usually harmless and caused by something you ate, drank, or took as a supplement. Normal urine ranges from nearly colorless to deep yellow depending on how hydrated you are, so a slight greenish tint typically means a pigment from food, vitamins, or medication is mixing with your urine’s natural yellow color.
What Makes Urine Yellow in the First Place
Urine gets its color from a pigment called urochrome, a byproduct of your body breaking down old red blood cells. How dark or light that yellow appears depends almost entirely on concentration. When you’re well hydrated, urine is diluted and pale. When you haven’t had enough water, the same pigment is packed into less fluid, producing a darker amber shade.
A greenish-yellow color happens when something adds a blue or green pigment on top of that baseline yellow. Think of it like mixing paint: yellow plus a touch of blue or green shifts the whole color. The most common sources of that extra pigment are B vitamins, certain foods, and a handful of medications.
B Vitamins Are the Most Common Cause
If you take a multivitamin or B-complex supplement, that’s the first place to look. Riboflavin (vitamin B2) is water-soluble, and your kidneys flush out whatever your body doesn’t need. The excess turns urine a vivid, almost fluorescent yellow that can lean green under certain lighting or when combined with other pigments in the bladder. This is completely normal and stops once the vitamin clears your system, usually within a few hours.
The brighter or more neon the color looks, the more likely B vitamins are responsible. Energy drinks, fortified cereals, and nutritional shakes often contain high doses of B vitamins, so you don’t necessarily need to be taking a supplement pill to see this effect.
Foods That Can Shift Urine Green
Asparagus is the best-known culprit. Eating it in large amounts can turn urine dark yellow or noticeably green, and it often adds that distinctive sulfur-like smell at the same time. Black licorice in large quantities can also produce various shades of green.
Artificial food dyes are another frequent cause. Green or blue dyes in candy, sports drinks, popsicles, or frosted baked goods pass through your digestive system and get filtered by the kidneys. Because your urine is already yellow, even a small amount of blue or green dye can create that greenish-yellow mix. If you ate or drank something brightly colored in the last 12 to 24 hours, that’s likely your answer.
Medications That Turn Urine Green
Several prescription and over-the-counter drugs are known to cause green or greenish-blue urine. The most commonly reported include:
- Amitriptyline, an antidepressant
- Indomethacin, a pain and arthritis medication
- Cimetidine, used for ulcers and acid reflux
- Promethazine, an antihistamine and anti-nausea drug
- Propofol, an anesthetic used before surgery
- Metoclopramide, a medication for nausea and gastroparesis
If you recently started a new medication and noticed the color change around the same time, the drug is very likely responsible. The color shift is a harmless side effect of how your body metabolizes and excretes the drug’s compounds. It resolves when you stop the medication.
Less Common Causes Worth Knowing
Urinary tract infections caused by certain bacteria, particularly Pseudomonas species, can occasionally produce a greenish tint. Unlike the dietary and supplement causes above, a bacterial infection usually comes with other symptoms: burning during urination, urgency, cloudy appearance, fever, or pelvic discomfort. A greenish color on its own, without any of those symptoms, is unlikely to be an infection.
Bile pigments can also play a role. If your liver or gallbladder isn’t processing bile normally, excess biliverdin (a green bile pigment) can end up in your urine. This would typically be accompanied by other signs like yellowing of the skin or eyes, pale stools, or abdominal pain.
How to Figure Out Your Specific Cause
Start with the simplest explanation. Think back over the last 24 hours: did you take a vitamin, eat asparagus, drink something with food coloring, or start a new medication? If you can identify any of those, try removing it and see if your urine returns to its usual shade within a day or two. Drinking more water will also dilute the pigment and make the color less noticeable.
If the greenish color persists for more than a few days with no obvious dietary or supplement explanation, or if it comes alongside pain, fever, blood, or increased thirst, it’s worth getting a urinalysis. This simple test checks for bacteria, blood cells, and chemical markers that can point toward infection, liver issues, or other underlying causes. In most cases, though, greenish-yellow urine turns out to be nothing more than a B vitamin or last night’s dinner passing through.