Excerpted from You’re Doing It Wrong: Dump the Myths, Misconceptions and Bad Advice You Believe

This is one of my pet peeves. In Against All Odds, I have a couple of entries where the person who survived also drank their urine. I have to emphasize that they survived despite drinking their urine.

Survival television has done considerable damage to public understanding of what actually keeps people alive in the field. Among the most persistently repeated and most actively harmful pieces of advice it has broadcast is this: if you have no water and you are dehydrating, drink your urine. It’s sterile and can be used to clean wounds. It’s available. It buys you time.

In Better Call Saul, they make a big deal out of this during one episode.

Urine is not sterile. It does not buy you time. It accelerates the dehydration it is meant to address. Drinking urine in a survival situation is one of the clearest examples in this book of a practice that feels logical, has achieved the status of received wisdom, and is precisely wrong in a way that can kill the person following it.

Start with the chemistry. Urine is the body’s mechanism for excreting waste — specifically, the metabolic byproducts that the kidneys have filtered from the blood and that the body needs to expel. These include urea, creatinine, dissolved salts, ammonia, and various other compounds the body has specifically processed for removal. The concentration of these substances in urine depends on hydration status: well-hydrated urine is dilute and pale; dehydrated urine is concentrated and dark, carrying a higher load of waste products per unit volume.

When you drink urine, those waste products re-enter the digestive system. The body must then filter them out again — which requires water to do. The kidneys cannot excrete waste without water as the transport medium. Reprocessing the solutes in urine draws on the body’s remaining water reserves, producing a net loss. The more dehydrated you are when you drink urine, the more concentrated that urine is, and the greater the water cost of processing it again. Each cycle of drinking and re-excreting leaves you with less water than you started with.

This is not a marginal effect. Military survival training, wilderness medicine curricula, and every major survival authority explicitly list drinking urine as a practice to avoid in survival situations. The Army manual is direct: it accelerates dehydration and should not be done. This guidance exists because people have followed the intuitive logic of “any fluid is better than no fluid” and made their situation measurably worse.

The claim that urine is sterile is also incorrect, though it is the more forgivable part of the myth and, to be honest, one I believed for a while. Urine produced by a healthy person in a healthy urinary tract is typically low in bacteria compared to many other body fluids — it is not crawling with pathogens in the way that, say, untreated surface water might be. But it is not sterile in any clinical sense. The urethra is not a sterile environment, and urine collected in normal circumstances carries some bacterial load. In a person who is already physiologically stressed by dehydration, exertion, or illness — exactly the conditions of a survival emergency — the bacterial load may be higher. “Relatively low in bacteria” is not the same as “safe to consume,” and in any case the bacterial content is not the primary problem. The waste product content is.

The related survival myth — that urine can be used to treat jellyfish stings — has been addressed elsewhere in this book and is equally wrong for related reasons: introducing a fluid of variable composition and pH to a sting site can trigger unfired nematocysts and worsen the injury.

In genuine survival dehydration, the hierarchy of water acquisition begins with finding actual water: surface water that can be purified by boiling or filtration, solar still construction using available plastic sheeting to condense ground moisture, vegetation sources such as certain fruits and plants, and in coastal environments, distillation of seawater by capturing steam. These methods are slower and more difficult than drinking available urine. They are also the ones that produce net hydration rather than net water loss.

The one partial exception sometimes cited: in the very early stages of dehydration, when urine is still relatively dilute, the net loss from reprocessing it is smaller. Some survival authorities have suggested that very dilute first-pass urine, consumed once, in a situation of absolute last resort with no other option available, produces a smaller net negative than no fluid at all. This is a narrow, contested, and heavily qualified position — not a recommendation. It is not a strategy. It is the outer boundary of what might be marginally less catastrophic than nothing in a situation where all other options have already failed.

That boundary should not be confused with advice.

The survival situation is already dire when dehydration becomes acute. Compounding it with a practice that accelerates the problem while creating the psychological comfort of having done something is not survival strategy. It is the feeling of action in the absence of useful action — which is, as this book has argued throughout, one of the most dangerous conditions a person can be in.

Find water. Conserve what you have. Do not drink the urine.

I cover water extensively in The Green Beret Preparation and Survival Guide.

BTW— the stories from those who survived and drank urine? It’s called survivor bias.

What is survivor bias? During World War II, the military wanted to add armor to the parts of returning bombers that showed the most bullet holes. An engineer told them to do the opposite. Why? The worst-hit planes never came back. All the data came from planes that made it to base. The spots with no damage were the worst places to be hit, because planes hit there didn’t return. Armor the engines and cockpit — the clean spots on the returning planes — because hits there were killing the planes that weren’t in the dataset.

Survivor bias in the urine-drinking myth works like this: we hear about the desert wanderer, the trapped climber, the lost soldier who drank their urine and lived. We don’t hear from the ones who drank their urine and died — they’re not telling stories. The sample is filtered by survival itself.

Worse, the survivors almost always survived despite the urine, not because of it. Aron Ralston, an entry in my Against All Odds book, drank his in Blue John Canyon; he was rescued shortly after self-amputating, and the ER physicians flagged the urine consumption as something that worsened his kidney status, not saved him. Mauro Prosperi did it in the Sahara during the 1994 Marathon des Sables — found nine days in, hospitalized in serious condition, and his doctors were clear that the urine and bat blood damaged him. Rescue saved him.

The bias compounds because the myth has narrative gravity. “He drank his own urine and lived” is a story. “He drank his own urine, died on day three, body recovered on day eleven” doesn’t get told — no protagonist left to tell it, and the family isn’t leading with that detail in the obituary.