What are some real reasons people don’t use helium-filled breast implants (except for the way it feels)?

Gases as a long term fill are suboptimal as they will, over time, diffuse across the shell and deflate (helium especially).As always, discuss your concerns with a board certified plastic surgeon (ABPS).Donovan Rosas MD
Board Certified by the American Board of Plastic Surgery
Member: American Society for Aesthetic Plastic
Surgery, American Society of Plastic Surgeons
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It's to do with the physical properties of helium as a gas. The gas atoms are so small that they will diffuse through the implant shell over time and the implant will deflate. You're not the first person to think about this and I think someone first mentioned this to me about 10 years ago. There is an implant called a B-lite implant which has a few molecules of silicone shaped in a different way and so the implant is lighter, but then if you look at the track record of implants with different fillers inside them, they haven't lasted very long and they have had a different set of complications. So I would want to wait until they have a few years of safety data before considering them