There are many anecdotal remedies for jellyfish stings, from urine to meat tenderizer, but this one may be the tastiest. A case report published in the journal Tropical Doctor tells the story of a 55-year-old scuba diver off São Tomé and Príncipe, a small island nation off west Africa, who was stung on his hand by a box jellyfish. The sting was incredibly painful and nothing seemed to provide relief. Urine had no impact, and hot water and lemon juice only made the pain worse. Then came lemon and oil.
According the the authors of the paper:
“Local dive masters who were familiar with treatments for box jellyfish envenomation recommended the application of a palm oil and lemon juice emulsion. 30 [hours] after the event the diver applied the recommended emulsion and experienced significant pain relief within the first 20 minutes.”
Does this mean that a tasty oil and lemon mix may be worth bringing to the beach? Not quite. It’s not clear what the lemon and oil is doing, but it might not have anything to do with the sting itself (30 hours is a long time. I’m skeptical that residual jellyfish stinging cells could be intact after so long. Might there still be venom on the skin’s surface? I don’t know). The authors also make the point that, “the venoms of jellyfish are known to be species-specific and, therefore different agents may have different effects.” For example, for sea wasp (Chiropsalmus quadrumanus) and Atlantic stinging nettle (Chrysaora quinquecirrha) stings, common anecdotal remedies like vinegar, alcohol, and ammonia actually make the pain worse, not better. So while an oil and lemon emulsion might work for the sting of box jellyfish around São Tomé, its usefulness as a general jellyfish sting treatment is unknown.
For major stings, it’s always important to consult a medical professional, especially for box jelly stings, which can be deadly. But for minor stings, I’m definitely going to keep oil and lemon in mind. Much more appealing than urine.
The Helm Lab Blog 
Please note that vinegar is not an ‘anecdotal remedy’ for jellyfish sting pain relief. Vinegar is known to inhibit the firing mechanism of jellyfish stinging cells. Vinegar has never been used for pain relief, it’s prime function is to stop the injection of venom. Vinegar (containing > 5% acetic acid) is recommended as treatment for potentially fatal jellyfish species such as box jellyfish by the American Heart Association, the American Red Cross and the Australian Resuscitation Council. A recent preliminary study at James Cook University, Australia demonstrated that while vinegar neutralises undischarged stinging cells, it may cause further discharge of already discharged stinging cells. This has yet to be fully proven.