“You should always pee on a jellyfish sting.”

The idea that urinating on a jellyfish sting provides relief is a widely held belief, often perpetuated by scenes in television shows and movies. This common misconception suggests that urine possesses some chemical property capable of neutralizing the venom (Review) or alleviating the pain. However, this folk remedy is not only ineffective but can actually make the situation worse, leading to increased discomfort and a more severe reaction from the sting.

Scientifically, urine's chemical composition is simply not suitable for deactivating the stinging cells, known as nematocysts, found on jellyfish tentacles. The pH and osmolarity of human urine are highly variable and almost never match the specific conditions needed to prevent further venom release. Instead, the fresh water content and inconsistent chemical makeup of urine can actually trigger any remaining unfired nematocysts to discharge more venom into the skin, intensifying the pain and the body's reaction to the sting. This immediate worsening of symptoms can be quite distressing for someone already in pain.

The persistence of this myth likely stems from a combination of factors, including a lack of readily available accurate information in emergency situations and the desperate human desire for any immediate solution to alleviate pain. Pop culture portrayals have also played a significant role in embedding this misinformation into the public consciousness, making it a go-to, albeit harmful, piece of advice. For effective first aid, experts consistently recommend rinsing the sting with vinegar, which can help neutralize certain types of jellyfish venom, or using seawater to rinse the area and carefully remove any visible tentacles, rather than applying urine.