Jellyfish Sting Treatment Facts

Jellyfish cause stinging by leaving nematocysts behind when they are touched. Nematocysts are tiny coiled stingers that, once triggered, inject venom into the patient. The amount and type of venom depend on the type of jellyfish, the number of nematocysts, area of bare skin, and the thickness of the skin. There is often a tentacle or two left behind after a sting as well, covered with nematocysts.

Jellyfish floating in the ocean
Steve Duchesne / The Image Bank / Getty Images

The trick to treating the pain of a jellyfish sting is to remove the nematocysts without triggering them to inject venom. Pressure triggers them, as well as freshwater and some chemicals.


  1. Remove any tentacles
    1. Use sand or a towel to remove the tentacles without touching them. Touching them with your bare hands will result in additional stings.
  2. Rinse away the sting area to remove nematocysts
    1. Here's where opinions differ. Ammonia, vinegar, vodka, denatured alcohol, water, urine, and many other substances have all been touted as the cure for jellyfish stings.

There's No Perfect Cure

Researchers in Australia, home of the deadliest species of box jellyfish, have spent years studying jellyfish stings. One thing is certain: nothing works for sure. Vinegar (5% acetic acid) has been shown to be the best rinse for box jellyfish. It neutralizes unfired nematocysts so they can't inject venom. When vinegar is not available, most research suggests using sea water to rinse away the remaining nematocysts. Freshwater is no good; it triggers nematocysts to inject venom.

A word of caution about vinegar: Studies suggest that vinegar actually worsens the pain of Portuguese Man of War, bluebottle, and other Physalia stings. These creatures are dangerous look-alikes to jellyfish. Vinegar has been shown to cause nearly 30% of Physalia nematocysts to fire.

Why Peeing Doesn't Help

Which brings us to urine. Urine consists of water and waste products of the body's bloodstream, which includes ammonia. Depending on the person and whether he or she is dehydrated, diabetic, on a protein diet, or dealing with myriad other conditions, urine may or may not be about as good as fresh water. In fact, urine contains so much fresh water that stranded folks can drink their own urine to survive. Since we know fresh water will often make nematocysts fire, the logical conclusion is that urine will do the same thing.

Research does not support the claims that urine can help treat jellyfish stings. On the Internet, you may find many anonymous bloggers sing praises of this readily available wonder tonic. Others tell stories of urine not working at all.

More About Jellyfish

Jellyfish venom can do more than cause pain; it can also cause anaphylaxis, a severe allergic reaction. Watch the patient for rash, hives, itching, shortness of breath, and swelling. If you suspect an allergic reaction, call 911 immediately or get the patient to a hospital.

Pain from jellyfish stings can last anywhere from a few minutes to several days or even weeks. Nonsteroidal anti-inflammatory drugs (NSAIDS) can be used for pain. Unfortunately, the only sure-fire treatment is time.

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.