Safe Sea: How To Prevent Jellyfish Stings

Safe Sea: How To Prevent Jellyfish Stings

The Jellyfish Sting is the most sophisticated weapon in nature.

This short report details a sunscreen formulation with a unique technology that exploits biochemical mechanisms to neutralize the sting from jellyfish tentacles and inhibiting the impact of jellyfish stings.

Although swimmers will still encounter jellyfish, the jellyfish stinging mechanism will not be activated against human skin that has been coated with the anti-sting sunscreen. This isn’t an after-sting treatment product but diminishes the intensity and may prevent a stinging episode entirely.  

Feeling no discomfort even with a jellyfish encounter is the best type of protection.


Jellyfish have, in many respects, remained remarkably simple organisms for more than 700 million years. They lack orientation, bones, and the ability to hear or see, but their complex stinging mechanism makes them fearsome ocean predators.

A jellyfish is loaded with billions of stinging cells.  A single jellyfish tentacle has a massive number of clusters (Figures 2A and B) consisting of hundreds of stinging cells (Figure 2C). A single stinging cell contains a dense capsule, within which is a highly folded ‘needle’ (Figure 2D).  During the actual jellyfish sting, the folded needle penetrates the skin to inject a venom known to have among the most potent toxins on earth (Fig 2 E).

Figure 2. Jellyfish stinging mechanism

A: Jellyfish and jellyfish tentacles
B: Closer look on single tentacles and stinging clusters
C: Clusters with hundreds of stinging mechanisms
D: Single cluster with stinging capsules and folded needles
E: Resting and discharge (Injection) stinging mechanism

Swimmers Trigger the Jellyfish Sting Mechanism

Jellyfish are poor swimmers and sometimes can’t avoid bumping into an unlucky swimmer. Unfortunately, stimulants from our skin can be sensed by jellyfish stinging cell sensors and can trigger a sting response (Fig 3A).

A jellyfish sting can develop a hydrostatic pressure of 150 atmospheres (similar to pressure in a scuba diving tank) within the capsule just prior to the act of stinging (Figure 3B). The capsule is forced open by this pressure, allowing the needle to be released (Figure 3C). During discharge, needle acceleration reaches 5 million times the force of gravity and penetrates the skin with a force similar to that of a bullet fired from a gun.

Jellyfish venom is injected into the skin within a fraction of a second, making a jellyfish sting one of the most rapid mechanical events found in nature. Over 2000 needles will penetrate one square millimeter (over a million per square inch) of human skin during contact with the jellyfish tentacle. This mass penetration of poisoned needles will generate pain, inflammation and a systemic reaction.

Figure 3: Activation of the jellyfish stinging mechanism.

Clownfish and Sea Anemone Inspire Anti-sting Sunscreen

The symbiotic relationship between the clownfish and the sea anemone is the inspiration for anti-sting sunscreens. This relationship between the clownfish and the sea anemone has attracted scientists and filmmakers alike.

For example, the starring role of the clownfish in Disney’s “Finding Nemo” uses sea anemones arms as protection from predators. The poisonous, stinging tentacles of sea anemones, a relative of the jellyfish, are loaded with the same stinging mechanism as jellyfish tentacles. Moreover, the sea anemone is a predator that uses its stinging cells to prey on fish. However, thanks to a protective layer, the clownfish is not recognized by the sea anemone as prey. This symbiosis is the basis for new sunscreens to prevent jellyfish sting.

Playing a Clownfish: How Sunscreens Deactivate Jellyfish Stinging Cells.

Years of studying cell biology, biochemistry, and stinging mechanisms provide the underlying knowledge that paved the way for this new technology to effectively de-activate the stinging cells firing (Fig 5).

Figure 5. Sunscreen deactivates jellyfish stinging cells.

  • It reduces tentacle skin attachments (Fig 5A)
  • Mimics jellyfish self-recognition (Fig 5B)
  • Blocks stinging cell sensors (Fig 5C)
  • Reduces the internal pressure in the stinging cell (Fig 5D)

It also works mechanically in that the slippery texture of Safe Sea sunscreen makes it difficult for stinging tentacles to attach. If they do, the cream absorbs secretions from the skin that would otherwise tell the jellyfish that it is in contact with prey. Chemical stoppers in the cream block pathways that trigger the stinging process and other stoppers reduce the pressure in the stinging cells, meaning that the stings cannot be fired, and our skin remains protected.

Clinical evidence

To evaluate the protection level of the sunscreen against different types of jellyfish sting, a testing protocol was developed in the Rambam Hospital Israel, and the Stanford Hospital in California. In Stanford, 24 subjects were randomized in a double-blind fashion to receive applications of either the sunscreen with jellyfish inhibitors (Safe Sea sunscreen) or a placebo sunscreen. Tentacles of sea nettle were removed from live jellyfish and were placed on the skin and left in contact with the forearm for 10 to 30 seconds before being removed with tweezers.

Following tentacle contact with the skin, the subject’s pain and inflammation were evaluated by a dermatologist. All arms pre-treated with the placebo sunscreen demonstrated erythema and all 12 subjects noted discomfort in that arm. In contrast, no arm pre-treated with the jellyfish sting inhibitor had clinically evident skin changes. Two subjects noted some discomfort in the arm treated with the sting inhibitor and in both cases this discomfort was rated as less than in the placebo-treated arm.

The results of this clinical test demonstrate that the new sunscreen provides effective protection against jellyfish stinging.  This concept has been tested several times and has proven to be effective against jellyfish stings. Rigorous testing has included clinically double-blind tests in medical centers, using several types of jellyfish.

  • Tested in Stanford Hospital in California against Pacific Ocean Sea Nettle.
  • Tested in Florida against Atlantic Box Jellyfish
  • Tested in Oslo to prove protection against Lioness Jellyfish
  • Tested in the Atlantic Ocean to protect against Sea lice
  • Tested in the Mediterranean against common jellyfish stings 
  • Tested in Okinawa and Japan to provide protection from Box Jellyfish and Blue Bottle in the Pacific Ocean.
  • Tested in Germany to protect against swimmer itch.

For the first time, there is a sunscreen that provides dual protection from both the sun and jellyfish sting. This leading new technology has been adopted by leading open swimmers and provides protection at sea for marathon swimming. This protection is globally available now for any swimmer.

Safe Sea Jellyfish Protective Sunscreen

Safe Sea SPF50+ lotion
$18.95 on Amazon

Safe Sea SPF40 Spray
$18.95 on Amazon

Safe Sea Safe lotion
$16.95 on Amazon

Thanks to Safe Sea’s cutting-edge sting protection, the Night Train Swimmers, a two-time WOWSA Award nominee, were able to complete a world record 339-mile ocean relay while swimming 6 days through large swarms of jellyfish. Patti Bauernfeind, who was nominated for the 2014 World Open Water Swimming Performance of the Year, faced extraordinarily difficult conditions while swimming across Monterey Bay, protecting herself with anti-jellyfish sting lotion.  Bauernfeind was adamant about how well the new skin-protection technology had protected at sea:

“There is no doubt in my mind that it protected me.” When asked whether she would use it in the next swim she answered “Absolutely! We may be a bit crazy to do these types of swims amid all these jellyfish, but we aren’t out of our minds”.

Covered with anti-sting protection, the Cyprus Israel swimmers were also well protected while setting a Guinness World Record when they swam 380 kilometers (236 miles) from Cyprus to Israel.

Disclaimer: WOWSA only recommends products or services used or recommended by the community. This post is sponsored by Safe Sea. Please see our privacy policy.

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