Urine to survive (or not): where is the science?

This post is a follow-up from "Piss: a survival resource".

I was poking through google search results from "how long can you survive on your own urine" and related searches. A few articles admonished the curious for even considering the idea, suggesting that you will die from kidney failure and dehydrate yourself even more quickly. Other articles extolled the health virtues of this apparently ancient health tonic and point to anecdotal evidence such as the guy from 127 hours surviving by drinking his own urine. I am including no links here because no one seems to know what they are talking about.

It seems obvious that drinking your own urine, at least at the beginning of a survival situation where it is still relatively dilute, is a no-brainer. I can cite personal experience to vouch for that. A good research question would be: where is the threshold at which recycling your urine becomes more harmful than helpful? Does it vary across individuals, and by how much? Is there a way you can tell when you've reached toxicity?

There seems to be no scientific literature, let alone consensus, addressing these questions. Since I couldn't find any scientific support, I just searched for news articles about people who have, indeed, survived by drinking their own urine. Here is a sampling of what I found:

"Forget and forgive." Sunday Times [London, England] 4 Aug. 2013: 6. Expanded Academic ASAP. Web. 11 Sept. 2013.

  • Kid gets locked up by the DEA in San Diego for smoking dope and gets forgotten for 4 days.
  • Survives by drinking his own urine.
  • Hospitalized for dehydration and kidney failure.
  • Unanswered question: would the dehydration and/or kidney failure have been worse if he hadn't drank his own piss? It seems like it. Four days is a long time without water.
"Buried brothers survive on urine, coal and humour." Times [London, England] 29 Aug. 2007: 30. Academic OneFile. Web. 11 Sept. 2013.
  • Two men get trapped in a coal mine. They dig their way out for 6 days.
  • They survive by drinking their own urine.
  • They suffer from kidney damage.
  • Seems doubtful they could have survived if they discarded their urine.
[various sources]
  • Aron Ralston survives 127 hours by drinking his own urine (he started with just 1 liter of fresh water).
  • Just about every article on the story indicates "he survived in part by drinking his own urine", and then immediately advises against that as a survival strategy. They cite the Army Field Manual, which puts urine on the "do not drink" list, but they don't even address the inconsistency: if that helped him survive, then why is it a bad survival strategy?
[various sources]
  • TV survivor personality Bear Gryllis supposedly has drank his own urine to prevent dehydration.
[various sources]
  • A kid gets lost in the Australian outback and survives for 3 days by drinking contact lens fluid and his own urine
  • We're talking 104 degree F heat.

"Hell at sea - Lost fishermen survived on their own urine", COREY ROBINSON, Sunday Observer staff reporter, Sunday, March 18, 2012. Obtained from Hell at sea.
  • Three fisherman adrift at sea for 28 days. Two drink their own urine to survive, one refuses and dies.
  • It is unclear from the article where else they obtained water from; I assume they didn't survive for 28 days just on urine.
  • Man survives 7 days buried in rubble from an earthquake in China by drinking his own urine.
  • Trapped under earthquake rubble, guy survives for 10 days by drinking his own urine.
  • Man gets lost in Louisiana bayou and survives for 4 days by drinking his own urine.
The list probably goes on, but I got tired of looking up stories. Interestingly, I then tried searching for "died from drinking urine to survive". None of the stories from above showed up in the search, but all the articles that warned against drinking urine as a survival tactic (without any evidence to back it up) did show up again. 

I did find one blog post that suggested you can drink your urine 1 to 2 times before it gets too concentrated to be of use. That seems reasonable, but again, no supporting evidence (1 to 2 times). The same is suggested here, again with no supporting evidence. I was unable to find a single article documenting either (a) someone dying from using their urine as a survival resource or (b) providing scientific evidence that it is more harmful than helpful.

A number of articles suggest that you should definitely not drink urine if you have a severe injury, because excess potassium and other electrolytes enter the blood stream and exit through your urine. Again, no supporting evidence out there, but that is something to consider.

It is possible that cases of people dying from using their urine to hydrate have not been documented because, well those people died in the wilderness or at sea or in the desert. The bottom line is, no one really seems to know for sure. 

I do know of a good amount of anecdotal evidence suggesting urine can keep you alive longer.

I do not know of any anecdotal evidence suggesting urine can kill you faster.

I will probably try to test this out further on myself to better answer the question. I've drank one cycle of urine, and felt much better after. Next time I work up the courage, I'll try two cycles and see how that goes.


  1. I think the tipping point is the psychological boost over the physical benefit, or harm, of drinking urine. The problem is most would only consider drinking it when they're already too dehydrated, offering least physical benefit. Aron Ralston thought it was doing him good so it kept him motivated even though it was actually damaging his body.
    It depends on the circumstances and how desperate you become. It may be worth it, if it'll maintain your will-to-live (or wishful-thinking). At least in the short-term.
    One reason you don't see many stories of people dying from drinking urine, at least in survival situations, is because most cultures teach people not to drink it (and it doesn't taste very good either). So, most people in survival situation never think or consider it an option. And, many would rather die than seemingly ruin their reputation after the fact.

  2. You raise an important point, maybe the MOST important point. The biggest part of survival is probably mental.

    But assuming you have the mental aspect locked down - you're super positive and motivated to stay alive - the basic questions about urine as a source of hydration still remain.

    At what point during the process of dehydration does it become more harmful than helpful to use urine as a water source?

    How much longer, if at all, could I stay alive than if I discarded all the urine?

    1. The biggest part is definitely mental. In the TV show 'I Shouldn't Be Alive', Science of Survival (SOS) - Escape from the Amazon, Myke Hawke tells a story about this guy who was flying a plane from LA to Vegas and crashed in the desert. It took rescuers 17 days to find him. During that time he did all the wrong things to stay alive (ie. worked in the day, drank his own urine, etc...) They ask him, what kept you hangin' on? He tells them, I'm going through a divorce and I'll be darned if I want my ex to get everything. Myke says, everyone has to find something that's important to them or something they value. That will to survive is the most important thing you can have.

      This guy had such will that he did all the wrong things and still survived. So he definitely had his mental aspects locked down. Perhaps drinking his urine helped or harmed him. Either way he thought it was doing him good (thinking positive, wishful thinking), and that's really what mattered. Just as Aron Rolston thought at the time. Since then, he now says drinking urine is a bad idea in his lectures.

      Watch a movie called 'The Canyon (2009)'. A fairly realistic survival movie in the desert with an ending I never really considered. Lack of water is just one of your problems in this movie.

      At what point... Not sure anyone could really give you good answer. The problem is remembering to start saving (or drinking) your urine as soon as you think you're in a survival situation (assuming no better water sources are available). And, that's if you even accept you're in a survival situation. The more diluted the better. According to Bear Grylls (from one of his Man vs Wild episodes) you should drink it fresh rather than store and ration it like Aron Ralson did (periodic small mouthfuls). I think because it's sterile when it's fresh.

      How much longer.... Good question. I don't know of any scientific tests or experiments anyone has done to this extreme, as it'd most likely be life-threatening depending how realistic they'd wanna go (ie. measuring kidney failure levels).

      I remember watching a TV show called 'Taboo' on The National Geographic Channel where they talked about the benefits of drinking urine. The problem here is, these people are hydrated and stay hydrated when they drink their own urine and so never show any ill effects. So, they think it offers benefits (more likely psychological benefits than physical). Kinda like the placebo effect.

      If you're so dehydrated your also not likely to be thinking straight either, along with being stressed, tired, hungry, irritable, injured, confused, etc...). So good sound judgement may be hard to come by. If you think you won't make it another hour or day then what do you have to lose drinking your urine? At least you 'think' you did something 'proactive' to prolong your life until hopefully a better opportunity or luck comes along, like when Aron Rolston miraculously found a small puddle to drink from soon after he escaped the canyon. That extra hour or extra day might be just enough to save your life. I'd say, it's a judgement call depending on the situation or circumstance.

      Similar to when they say don't drink untreated water as you'll likely get very sick. Initially it's a bad idea, but when you get desperate, it's better to risk getting sick to buy yourself more time rather than dying of dehydration. It'd suck to die the day before you get rescued, ha ha.

    2. Interesting that Aron Ralston advises against it in lectures. Do you have any more detail about that - documentation or his reasons why, etc?

    3. It was a web video I saw of him a few years ago. I think it was a lecture in Europe somewhere, apparently recorded not long after his 'Between A Rock And A Hard Place' book came out (mid-2000's). It was a Q&A session, I think, when someone asked him about drinking urine. I don't remember him giving a good reason why.

      If I remember right, when I read his book (better than the movie), he does mention the urine did a number on his mouth, tongue, and lips (ate away the inner lining).

      I tried to do a quick Google search, but can't find what I remember. If I find it, I'll let you know.