# Yellow Urine
**URL:** https://boards.straightdope.com/t/yellow-urine/7889
**Category:** Factual Questions
**Created:** [February 28, 2000, 1:21am UTC](https://boards.straightdope.com/t/yellow-urine/7889 "2000-02-28T01:21:00Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@toecutter](https://boards.straightdope.com/u/toecutter)
#### Post date: [February 28, 2000, 1:21am UTC](https://boards.straightdope.com/t/yellow-urine/7889/1 "2000-02-28T01:21:00Z")
If urine is such a good bleach, why is it yellow?
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### Author:  [@tbea925](https://boards.straightdope.com/u/tbea925)
#### Post date: [February 28, 2000, 1:57am UTC](https://boards.straightdope.com/t/yellow-urine/7889/2 "2000-02-28T01:57:00Z")
So you can write your name in the snow.
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This sig not Y2K compliant. Happy 1900.
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### Author:  [@Ringo](https://boards.straightdope.com/u/Ringo)
#### Post date: [February 28, 2000, 2:22am UTC](https://boards.straightdope.com/t/yellow-urine/7889/3 "2000-02-28T02:22:00Z")
Actually, you could write your name in the snow if it was purple.
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### Author:  [@Sigmundex](https://boards.straightdope.com/u/Sigmundex)
#### Post date: [February 28, 2000, 3:23am UTC](https://boards.straightdope.com/t/yellow-urine/7889/4 "2000-02-28T03:23:00Z")
Actually, here’s the process: the body removes all the “brown” from the Coke you drink, and stains your shit with it. After all, not all the food you eat is brown, is it? Your body saves up all the “yellow” from the food you eat and colors your piss yellow with it. And man, is my piss yellow around Easter, must be all those yellow Peeps. There, seems pretty obvious now, doesn’t it? Don’t ask me where all those colors go, but when they do autopsies, they must find freakin’ rainbows in there.
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### Author:  [@melanietarrant](https://boards.straightdope.com/u/melanietarrant)
#### Post date: [February 28, 2000, 4:10am UTC](https://boards.straightdope.com/t/yellow-urine/7889/5 "2000-02-28T04:10:00Z")
i know why “solid” human waste is brown.
when you eat food, it is broken down into it’s basic nutritional components and carried throughout the body to individual cells via blood.
well, the life span on individual blood cells is only a few days. once a blood cell dies, it is removed from stream and evacuated from the body.
have you ever noticed dried blood stains turn a brownish color? it’s no coincidence that human waste is also that brownish color. a very large percentage is dead blood cells.
i don’t know why urine is yellow though. but did you ever notice it’s a brighter(more cheerful) shade after you take vitamins? why is that?
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### Author:  [@upstatic](https://boards.straightdope.com/u/upstatic)
#### Post date: [February 28, 2000, 4:21am UTC](https://boards.straightdope.com/t/yellow-urine/7889/6 "2000-02-28T04:21:00Z")
I heard somewhere that urine is clear if the body does not absorb vitamins and such from the liquid. It is passed through the body immediately. And if components from the liquid are absorbed into the body, the more yellow the urine would be.
I don’t know how true that is. But try drinking a really, really big glass of water. If a few minutes you’ll have to go to the bathroom, the urine will be clear.
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R.J.D.
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### Author:  [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)
#### Post date: [February 28, 2000, 4:33am UTC](https://boards.straightdope.com/t/yellow-urine/7889/7 "2000-02-28T04:33:00Z")
upstatic,
I think I’ll leave that noble experiment to some more intrepid seeker of knowledge.
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and the stars o’erhead were dancing heel to toe
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### Author:  [@Cowboy\_Greg](https://boards.straightdope.com/u/Cowboy_Greg)
#### Post date: [February 28, 2000, 4:51am UTC](https://boards.straightdope.com/t/yellow-urine/7889/8 "2000-02-28T04:51:00Z")
The yellow color is caused by urochrome, which is a product of blood cell breakdown and is filtered out by the kidneys. B vitamins in particular seem to make your urine bright yellow; I’m not sure what the mechanism for that is, but I’m sure one of our resident M.D.s can elaborate further (I’m not a doctor, and I don’t play one on TV).
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Shared pain is lessened; shared joy is increased.
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### Author:  [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)
#### Post date: [February 28, 2000, 7:20am UTC](https://boards.straightdope.com/t/yellow-urine/7889/9 "2000-02-28T07:20:00Z")
Straight dope huh.
Simple answers to all. Poop brown and pee is yellow because of coumpounds called “bile pigments”. Bile is used to help digest fats, the pigments are excreted in waste. The one in urine is is called urichrome the names of ones in feces escape me.
Urine is a bleach because almost immediately on excretion the urea in it begins to break down into ammonia and other compounds.
Mel, if a “very large percentage” of your fecal mater is blood, you need to see a doctor. That is definatily not normal.
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### Author:  [@AWB](https://boards.straightdope.com/u/AWB)
#### Post date: [February 28, 2000, 1:27pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/10 "2000-02-28T13:27:00Z")
Cowboy Greg, I thought it was Vitamin _A_ that turned urine bright yellow.
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Wrong thinking is punished, right thinking is just as swiftly rewarded. You’ll find it an effective combination.
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### Author:  [@Andy](https://boards.straightdope.com/u/Andy)
#### Post date: [February 28, 2000, 1:46pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/11 "2000-02-28T13:46:00Z")
> [@](#):
>
> The one in urine is is called urichrome the names of ones in feces escape me.
Bilirubin?
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### Author:  [@NickyLarson](https://boards.straightdope.com/u/NickyLarson)
#### Post date: [February 28, 2000, 3:32pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/12 "2000-02-28T15:32:00Z")
If you’re taking iron supplements it make your urine bluish. I remember reading about a WarnerBros.(?) animator who was taking iron pills. He noticed the color change, and adjusted the dosage till he was peeing green.
I’ve also noticed that after a lot of beer my piss is almost clear. (But beer is yellow to begin with, so…)
I like the theory about Coke and shit, though…
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If it jams, force it; if it breaks, it needed replacing anyway.
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### Author:  [@handy](https://boards.straightdope.com/u/handy)
#### Post date: [February 28, 2000, 4:30pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/13 "2000-02-28T16:30:00Z")
Billyrubin makes shit brown. Urea makes pee yellow. The more water you drink, lighter it is.
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### Author:  [@NickyLarson](https://boards.straightdope.com/u/NickyLarson)
#### Post date: [February 28, 2000, 4:43pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/14 "2000-02-28T16:43:00Z")
Billyrubin makes shit brown? Is this for real? Is this verifiable? I knew a guy named Billy Rueben a long time ago, and boy, was he a prick!
I’d love to know if this is true.
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### Author:  [@manhattan](https://boards.straightdope.com/u/manhattan)
#### Post date: [February 28, 2000, 4:56pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/15 "2000-02-28T16:56:00Z")
[Why is, um, fecal matter brown?](http://www.straightdope.com/classics/a2_381.html)
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[Change Your Password, Please](http://204.95.48.199/cgi-bin/ubbcgi/ubbmisc.cgi?action=getannounce&ForumNumber=3&Start=2451545.99&End=2451911&Session=2451598.1854) and don’t use HTML, as it has been disabled
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### Author:  [@Surgoshan](https://boards.straightdope.com/u/Surgoshan)
#### Post date: [February 29, 2000, 4:33am UTC](https://boards.straightdope.com/t/yellow-urine/7889/16 "2000-02-29T04:33:00Z")
When you drink a lot of beer, it dehydrates you. It pulls a lot of water out of your system and makes you pee a lot. Pee is clear when it’s diluted by a lot of water. Ipso facto, when you drink a lot of beer, it makes you excrete a lot of water, that dilutes the piss, boom, clear piss.
Then the next day you’re dehydrated as all hell and your piss is practically crystalline there’s so little water.
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I sold my soul to Satan for a dollar. I got it in the mail.
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### Author:  [@NickyLarson](https://boards.straightdope.com/u/NickyLarson)
#### Post date: [February 29, 2000, 4:38am UTC](https://boards.straightdope.com/t/yellow-urine/7889/17 "2000-02-29T04:38:00Z")
I hadn’t been back here all night, manhattan, thanks for that link. I have **GOT** to send it to a friend or two!
😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃 😃
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If it jams, force it; if it breaks, it needed replacing anyway.
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### Author:  [@siva](https://boards.straightdope.com/u/siva)
#### Post date: [February 29, 2000, 6:17am UTC](https://boards.straightdope.com/t/yellow-urine/7889/18 "2000-02-29T06:17:00Z")
I have no answer for the question, but I was wondering if salt content had anything to do with it. When I drink or eat something that is salty my pee is yellower\<—is that a word?
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### Author:  [@NanoByte](https://boards.straightdope.com/u/NanoByte)
#### Post date: [February 29, 2000, 11:08am UTC](https://boards.straightdope.com/t/yellow-urine/7889/19 "2000-02-29T11:08:00Z")
And, of course, what color do you get in either one when you eat beets?
OK, so now we’re right back to the basic ingredients of modern art.
Ray (Do not recycle used canvases through the plumbing. I guess the Millions **do** actually do more than teem.)
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### Author:  [@toecutter](https://boards.straightdope.com/u/toecutter)
#### Post date: [February 29, 2000, 3:30pm UTC](https://boards.straightdope.com/t/yellow-urine/7889/20 "2000-02-29T15:30:00Z")
I think I can understand why urine is yellow. Thank you all.
But what I am trying to find out has to do with the bleaching properties of urine. Ages ago, the Romans used to bleach their togas and other fine linen in large vats of urine. The tunics that the slaves wore were brown – natural un-bleached fibers.
If we can suppose that their urine was also yellowish, why didn’t it stain their fabrics. Why did their clothes come out shiny white?
And no, it wasn’t because it was _new and improved_ Urine.
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