does epipen work underwater, through a nalprene suit?

I wouldn't use an epi underwater. How it injects the adrenaline into your system is that it uses compressed air (or oxygen/nitrogen) to push the plunger down. When you go under water, pressure increases, and gases become more dense.

This means that at depth, an epipen will inject you slower, and at some point not at all.

If you're worried about an allergic reaction to jellyfish, keep one on the boat. Your buddy'll be able to get you back to there if something goes wrong.

Per the EpiPen website, it is spring loaded. I would not use it under water. If you are NOT having an anaphylactic reaction, make your way up to the boat at a slow 30 feet per minute. You can probably skip the safety stop. If you are having trouble breathing, make an emergency assent exhaling the entire way at a steady pace; do not hold your breath. If your reactions are that severe, you should not dive because you WILL get decompression sickness.

As far as the neoprene goes, it depends how thick it is. There are different thicknesses. You will probably need to take you wetsuit off before using the EpiPen.

Yes, it will work. It will go though neoprene like a hot knife through butter. But get to the surface before you use it and make sure someone else is with you incase it doesn't work. Check with you doctor to make sure epi will work for jellyfish first. Not any jellyfish where I grew up.

The epi pen would probably be able to go through the swimsuit, but I'm not sure how being submerged in water might affect it. You might want to keep it in some kind of watertight case, and only remove it if you need to use it.

if you have a spare needle or at least one that is the same gauge as the epipen, try sticking it through the nalprene and see if it will go in. I don't know how thick they are, but make sure the needle can get to the depth it needs to be at in the muscle

Nope... just trust a reputable brand. Look at the fabric, is it thick? Does it have a lining on the inside? Then if it does, it's prob not see through. Roxy and Billabong have nice ones. Puma too.

Remember how pressure effects things, I d consult someone with professional knowledge before you dive with one, otherwise leave it on the boat. Yes it will go through the suit, but wether or not it will inject under pressure, or the pen with rupture under pressure, or how pressurized epinephrine will effect effect you, I would suggest more info than an internet forum...

I know for a fact it will work in the water, however, probably not at any depth. So if you are near the surface, yes, if not, then no.

And yes, it will go through neoprene.

Check with your doctor/pharmacist. I am a little unsure as to whether you can take the pen underwater. I am almost sure it will not work there.

Are you sure your allergies are safe for scuba?

Doctor, for sure!