The Shark Transplant Myth: Why This Medical "Fact" Is False

You've probably heard this one before: shark corneas are so similar to human ones that they're used in eye transplants. Some versions even claim shark bone marrow helps graft human bones. It sounds plausible—sharks are ancient, resilient creatures, so why not borrow from their biology? There's just one problem: none of it is true.

The Cornea Confusion

Human corneal transplants use only human donor corneas. Period. The American Academy of Ophthalmology, Mayo Clinic, and every major medical institution confirms this. When someone needs a cornea transplant, surgeons replace the damaged tissue with a clear, healthy cornea from a deceased human donor.

So where did the shark story come from? Shark corneas are remarkably similar to human ones in structure—they're transparent, layered, and share some biomechanical properties. This similarity has made them useful for research, helping scientists understand corneal function. But research is very different from clinical use.

Animal-to-human corneal transplants, called xenotransplantation, have been attempted since the early 19th century using pigs, sheep, dogs, and rabbits. None succeeded long-term. Today, scientists are exploring pig corneas as a future possibility, but it remains experimental. Sharks aren't even in the running.

The Bone Marrow Impossibility

This claim fails an even more basic test: sharks don't have bone marrow. Unlike humans and other bony vertebrates, sharks have skeletons made of cartilage—the same flexible tissue in your nose and ears. No bones means no bone marrow. It's biologically impossible.

The confusion might stem from the "Shark Screw®," a medical device used in orthopedic surgery. Despite the predatory name, it's made from human donor bone tissue, not sharks. It's just branding.

There is one shark-derived bone product, but it's for veterinary use: bioceramics made from shark teeth (heated to 950°C) used in cat and dog surgeries. Still not bone marrow, still not for humans.

Why the Myth Persists

Shark myths are everywhere. They don't get cancer (false). They never stop swimming (mostly false). They're living fossils (oversimplified). These stories spread because sharks occupy a unique cultural space—powerful, mysterious, ancient. When a "fact" sounds just plausible enough, it sticks.

The medical angle adds credibility. "Doctors use shark parts!" feels like insider knowledge. But medicine is built on rigorous testing, regulatory approval, and published evidence. If shark corneas were viable, we'd have clinical trials, FDA approvals, and surgical protocols. We have none of that.

Real bone grafts use human donor bone, synthetic materials like calcium phosphate, or the patient's own bone harvested from the hip. Real corneal transplants rely on human donor registries—which face serious shortages. Over 12 million people worldwide need corneal transplants, but only 1 in 70 receives one due to donor scarcity.

That's the actual medical challenge: not finding shark alternatives, but getting more people to become organ donors. The shark story is a distraction from the real lifesaving work happening in transplant medicine.

What Sharks Actually Give Us

Sharks contribute to medical science in legitimate ways. Squalamine, a compound from shark tissue, is being studied for antiviral and anticancer properties. Shark antibodies have unique structures that inspire research into new drugs. Their cartilage has been investigated (controversially and inconclusively) for arthritis treatments.

But these are research avenues, not clinical realities—and certainly not transplant materials. The difference matters. Science moves slowly, deliberately, with layers of testing before anything reaches patients.

So the next time someone mentions shark corneas in surgery, you can set the record straight. It's a myth built on a grain of truth, wrapped in misunderstanding, and spread by people who never checked the source. The real story—human ingenuity solving donor shortages and perfecting transplant techniques—is far more impressive than borrowing from sharks.