Time go again to the A Moment of Science mailbag. A listener writes:
Dear A Moment of Science,
Is it OK to drink urine? Not that I want to, I'm just curious.
The Gross Answer
Well, the short answer is yes if you're trapped somewhere without water, you can drink your own urine, or even someone else's, in order to survive a little longer.
But wait. Besides the fact that drinking urine is kinda gross, doesn't it contain chemicals the body's trying to get rid of? Isn't that the whole point of urinating?
Urine is still safe to drink in the short term. Normally, urine is about 95 percent water and only five percent waste minerals such as excess potassium and calcium. So at least at first, drinking urine isn't that different from drinking water.
But if you kept recycling urine by urinating and drinking it multiple times, wouldn't those minerals eventually build up until the urine was no longer safe?
Recycling Can Be Bad
Over several days, your urine would become saturated with minerals. And drinking it would really tax the kidneys, whose job it is to flush unwanted minerals and toxins from the body. Drink urine long enough and you may go into kidney failure.
On a related note, you may have heard that in some cultures, urine is used as medicine. There's no hard evidence that urine has any curative powers, which doesn't mean it has none. But urologists tend to believe that whatever healthful powers drinking urine has would be negated by toxic buildup in the kidneys.
- Is it a good idea to drink urine when water is scarce? (Slate)