New Research Findings to Standardise First Aid Treatment of Jellyfish Stings

Lion’s mane jellyfish in Dingle harbour. Photo: Nuala Moore
Jul 26 2017 Posted: 10:46 IST

Vinegar and heat are found to be the best treatment for stings from lion’s mane jellyfish

New research from NUI Galway and the University of Hawai’i at Mānoa has identified the best way to treat a sting from the lion’s mane jellyfish (Cyanea capillata). The lion’s mane jellyfish is the most problematic jellyfish in Ireland and the UK with 100’s of bathers being badly stung each year. With over a 1,000 tentacles that can stretch up to four or five metres in length, a bad sting from a lion’s mane jellyfish can cause severe local reactions and extreme pain.   

The research, published in the international journal Toxins shows that the best first aid for a lion’s mane sting is to rinse with vinegar (or the commercial product Sting No More® spray) to remove tentacles, and then immerse in 45°C (113°F) hot water (or apply a heat pack) for 40 minutes. The results mirror a recent NUI Galway and University of Hawai’i study on stings from the Portuguese man o’ war and previous work on box jellyfish stings.

Dr Tom Doyle, lead author of the study and Lecturer in Zoology from the School of Natural Sciences at NUI Galway, said: “What most people don’t understand is that these jellyfish - the lion’s mane, the Portuguese man o’ war and a box jellyfish, are as different from each other as a dog and a snake.

“Therefore when developing first aid treatment for a jellyfish sting it is very important to test different treatments on these very different types of jellyfish. Now that we have shown that vinegar and hot water work on these three jellyfish species, it will be much easier to standardise and simplify first aid for jellyfish stings where many different types of jellyfish occur.”

In Ireland and the UK, current best practices recommend using sea water and cold packs, which is not the correct action for treating these jellyfish stings as it induces significant increases in venom delivery, while rinsing with vinegar or Sting No More® Spray did not. Dr Doyle now hopes to bring together members of the Jellyfish Advisory Group in Ireland to discuss his latest findings. However, it is important to remember that most jellyfish stings in Ireland and the UK are no worse than a nettle sting.

To support research on the distribution and abundance of jellyfish in Ireland, members of the public can record any sightings at:

To read the full study in Toxins, visit:

Video of lion’s mane jellyfish:


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