Never pee on a jellyfish sting: A venom expert busts our biggest myths about toxic creatures

Look but don’t touch.
Look but don’t touch.
Image: Reuters/Richard Green
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Snakes, scorpions, and other venomous species have always loomed large in the human imagination. Their awesome ability to dismantle our most essential bodily systems pops up in early written records from Aristotle to The Bible. But their potent toxins have also inspired some of the most persistent—and dangerous—myths I’ve seen as a scientist. It’s time to bury treatment ideas like sucking out snake venom and peeing on jellyfish stings in the past. Here are three of the biggest urban legends I’d like to dispel:

Myth: Pee on your friends to soothe their jellyfish stings.

Fact: Douse stings thoroughly with vinegar, then soak in hot water to relieve pain.

I can’t confirm that the TV show Friends came up with the idea of peeing on a jellyfish sting. But the episode where Monica’s pals come through for her after a nasty sting certainly seems to have solidified this myth in the public consciousness.

Since then, people have come up with all kinds of ideas as to why urine might work in this scenario, including its acidity (a pH of 6.0 on average, which is barely acidic) and warmth (a cozy 98 degrees, just like your body). But as a venom scientist, I have tested this cure out myself—in the lab. I’ve watched tentacles from box jellies and Portuguese man o’ war react to urine. And more often than not, the solution causes their venomous stinging cells to fire. Though the intensity of the reaction varies along with the urine itself, at best, urine is inert, at which point you might as well use seawater instead. And at worst, pee causes so much stinging that the jelly would almost certainly inject more venom into you.

So here’s what you should do: keep your pants zipped and stash a bottle of vinegar in the car instead. Treating the wound with vinegar causes the jellyfish’s stinging cells to become fixed and unable to fire. And if you’re really in pain, submerge the stung area in hot (not scalding!) water for 20-30 minutes. Multiple studies have shown that heat works better than ice for relieving pain.

Myth: Suck out snake venom from a bite.

Fact: Just go get help as fast as you can.

Venomous snakes are some of the most dangerous venomous animals, capable of delivering large amounts of potentially lethal toxins with a single bite. Because snake venom can be so dangerous, I can see why people began to think that removing the venom before it spread through the body could save victims’ lives. But why we then settled on the idea that the best way to solve the problem is to suck on the wound to draw the venom into our own mouth is beyond me.

Unfortunately, a lot of proposed ways of removing venom, from suction devices to cutting around a bite (“lancing”), don’t work. Once snake venom is injected in the body, it immediately goes to work, hitchhiking in the blood to get around. It only takes 60 seconds for your blood to travel all the way around your body—so you’re never going to get to all of the venom before it’s spread. Instead, by attempting to remove the toxic fluid, you waste precious time, likely cause more damage, and might even risk harming yourself.

So if you’re with someone who has been bitten by a venomous snake, make sure they’re safely away from the animal, then get straight to calling 911. If you got a good look at the animal, note the species or what it looked like in order to help doctors determine which anti-venom to use. Keep the victim calm and as still as possible, with the bite area positioned lower than the heart. You’re not going to be able to treat the person on your own, so getting them medical attention is your top priority!

Myth: This big sore appeared overnight—damn spiders!

Fact: Rarely are mysterious lesions attributable to eight-legged assailants.

We’ve gotten it into our heads that any unexplained bump, mark, sore, or lesion must be the work of a tenacious arachnid that buried its fangs into our flesh as we slept. But in reality, very few of the 45,000 spider species have fangs that are actually capable of penetrating our skin. Even those that can, like black widow spiders, are reluctant to bite at all. And when they do, their bites are generally mild. In fact, only one small group of spiders—the recluses and their relatives—can even cause the gross, weeping sores that we often think are “spider bites.”

When scientists take a closer look at these alleged spider attacks, most are attributable to other bugs. One study found that only 3.8% of “spider bites” were actually bites from spiders. There was even a case where anthrax poisoning was misdiagnosed as a spider bite. But doctors fall victim to anti-spider bias, too, frequently taking their patient’s word for the cause without actual evidence.

Such misidentifications can have very serious implications. Potentially grave infections like methicillin-resistant Staphylococcus aureus (or MRSA) can be overlooked as ‘just a spider bite,’ delaying essential medical care. So unless you actually see a spider bite you, you should probably assume that the mysterious and sudden growing wound on your arm isn’t a spider bite. And you might want to get it checked out by a professional, just in case.