Explore different pig-to-human xenotransplantation possibilities, including using pig pancreatic cells for treating diabetes.

Xenotransplants are an experimental last resort for the terminally ill when they cannot or will not receive a human organ.

Pig-to-human transplant work has raised concerns about donor pigs' living conditions.

Pigs are of particular interest for xenotransplantation because they are close to human size, are easily raised in captivity, and have large litters.

Cross-species transplantation has been attempted in medicine for more than 300 years.

Chinese scientists transplanted a pig lung into a human being in 2025—but it had to be removed.

Read why one man agreed to get a pig kidney in 2025 to replace his own failing organ

The 68-year-old New Hampshire man told USA Today that a motivator for the experimental surgery was his belief that he was going to die anyway, and other people suffering from kidney disease could gain valuable insights. Yet the surgery bought him time—he lived 271 days with a pig organ and later received a human kidney transplant. Clinical trials began in 2026 to test the pig xenotransplants in more people.

Scientists may have discovered why gene-edited pig kidneys are rejected in humans

In November 2025, researchers studying how a brain-dead donor’s body responded to the transplantation of a genetically engineered pig kidney, published that they’ve identified immune system reactions that may explain why these pig organs get rejected. What’s more, they were able to reverse the rejections with an already available drug combination and the kidney functioned well. They also pinpointed a way to detect a potential rejection up to five days sooner.

See how pig heart valves have been placed in humans since 1965.

A first-of-its-kind clinical trial taps livers from gene-edited pigs to clean blood

The experimental dialysis-like treatment from United Therapeutics, eGenesis, and OrganOx, is designed to help people with liver failure. The therapy, which involves attaching the modified pig liver externally, filters a patient’s blood so their own livers can temporarily rest and perhaps heal.

After the first gene-edited pig heart transplant patient died, a latent pig virus was discovered inside his xenotransplant.

The global xenotransplantation market may already be valued at more than $13B.

Pig organ transplants are apparently kosher—you just can’t eat them

Science writer Mary Roach speaks with journalist Terry Gross about her latest book, “Replaceable You: Adventures in Human Anatomy” and discusses topics including why pig organs have become of such interest and what religious leaders have told her about pig organs and compliance with Jewish dietary law.

US federal researchers are blocked from putting certain human cells in animals

In 2015, US policymakers put a halt to any government-funded work that would insert human stem cells into animals. The reasoning was that human cells might spread through the animal's body and perhaps to its brain, blurring the line between humans and nonhumans. The ban remains in place today even as gene-edited pig parts are being placed in humans.

One man lived with a gene-edited pig kidney for 271 days, setting a record, before he received a human kidney.

Alpha-gal allergy is a problem for red meat lovers, and that same alpha-gal sugar is an issue for xenotransplants, too—since it's present in pigs, human bodies reject pig-to-human transplants as foreign once they detect the substance.

Early peptide research focused on isolating the substances from animal tissue

In the first half of the 20th century, peptides including insulin and adrenocorticotropic hormone were isolated from animals to provide life-saving medicines. ACTH was isolated from the pituitary glands of cows and pigs and insulin was isolated from the pancreas of dogs and cows.

Scientists using gene therapy recently managed to regenerate retinal cells in the lab—a breakthrough for mammals that could potentially lead to future treatments for human retinal diseases.

See the first dog ever treated with insulin—a peptide

Frederick Banting and his graduate student Charles Best were the first to isolate the peptide insulin from dogs. They induced diabetes in the animals and then treated them with this peptide.

Pig brain cellular activity was restarted hours after death in study published in 2019

Yale University scientists restored basic cellular activity and circulatory function in pig brains about four hours after death with a synthetic cocktail of preservatives and nutrients. This work— which didn't restart electricity activity in the brain or consciousness—could help advance future human stroke and brain injury treatments.

A clinical trial is underway in 2026 to help kidney transplant recipients avoid a lifetime of immunosuppressing drugs

This later-stage clinical trial, in Chicago and Taiwan, evaluates the efficacy and safety of a new cellular therapy that may be swapped in for immunosuppressing drugs among kidney transplant recipients. The study randomizes people to either receive standard immunosuppressants or this cellular therapy and fewer immunosuppressants. It only includes kidney transplant recipients receiving organs from live donors so transplant surgery timing won't hinge on the unpredictable schedule of performing surgery and follow-up care when a donor dies.

Transplanted organs can be rejected by the body immediately, months after transplant, or slowly over years

Organ rejection remains a huge challenge for organ transplant recipients. Rejection occurs when a recipient's immune system identifies a transplanted organ as foreign and attacks it. Recipient-donor screening processes try to match antigens to help reduce this risk.

Gene therapy can occur inside the body, but it can also be completed outside the body—with scientists treating cells in the lab, and then those corrected cells are transplanted back into the body.

Transplant organs don't always last a lifetime—that's where retransplants come in

How long a transplanted organ lasts depends on a variety of factors including the type of organ and the health of the recipient. Sometimes organs can last many decades, but other times people may need retransplants, which means another transplant following a previous one. Retransplants are most common with kidneys.

As of 2025, perfect synthetic replication of natural organs remains elusive

Advancements such as 3D printing muscles, performing vaginal reconstruction with colon tissue, and growing organs in a lab have shown promise, but artificial options and transplanting substitutions continue to exhibit functional and performance limitations compared to their natural equivalents.

Artificial intelligence may improve organ donation systems—and even organ health

Mayo Clinic transplant experts suggest that artificial intelligence could potentially improve organ donation systems in several ways, including better identifying patients most at risk for organ rejection, enhancing donor-recipient matching, and helping to avoid organ transplant needs by identifying health issues earlier.

Immunosuppressants enable organ transplants, but come with severe side effects

This drug cocktail helps to lower your body's natural response to attack a transplanted organ. Such medications usually need to be taken for a lifetime after receiving an organ and can come with serious side effects including high blood pressure, diabetes, increased risk of some cancers, and high cholesterol, among others.

Leonard Thompson was the first human to receive an insulin injection for diabetes

In January 1922, the 14-year-old was the first person to receive an insulin injection to treat diabetes, just months after insulin was isolated in dogs and used to treat their induced diabetes. Thompson had an allergic response to an apparent impurity in the injection, but his second dose, 12 days later, was a success.

In 1984, a dying infant lived for three weeks with a baboon heart inside her chest.

Living donations most commonly involve a kidney or part of a liver

In 2023, more than 6,900 transplants were made possible thanks to living donors. Living donation is when a living person donates an organ or part of an organ—usually one of their two kidneys or part of the liver, since that organ can regenerate in a healthy person. Much more rarely, living donors donate other organs. Living donations often occur when someone wants to ensure a loved one has certainty that they will quickly receive a needed organ.

In vitro gametogenesis: using induced stem cells to fertilize eggs

Using stem cells from skin and mouth cells could save hopeful parents time and money and spare egg donors from significant amounts of discomfort throughout the process. There are potential consequences, not just for infertility treatment, but for the ability to create customized cells of any type.

Understanding insulin

Scientists Daniel and Kelly talk with researcher Dr. Katrine Whiteson about diabetes, the history of insulin production, and Dr. Lydia Villa-Komaroff—an essential member of the team who discovered that bacteria could be induced to produce insulin. Listen to discover interesting facts about the life-saving medicine and how it works in the human body.

Diabetes drug GLP-1 is a peptide (that's what the 'P' is for).

Recombinant DNA technology turns microorganisms into protein factories

Genes for molecules such as insulin can be inserted into loops of bacterial DNA called plasmids and reinserted into bacteria. Once placed in fermentation tanks, these bacteria use the gene to produce these molecules, which are then harvested and purified for eventual use.

How to turn any cell of the body into a stem cell

Scientists have developed techniques allowing them to 'reprogram' any cell in the body into an induced pluripotent stem (iPS) cell, which can be used to create either more stem cells or specialized cells for use in experimental medical treatments. This page gives readers a brief introduction to the history of iPS cells, what researchers are studying with iPS cells, and challenges associated with iPS research.

Organoids: 3D organs grown from stem cells in the lab

An organoid is a three-dimensional construct composed of multiple cell types that originate from stem cells that can simulate the architecture and functionality of native organs. One big benefit of these lab-grown organs is that drug candidates can be tested in model systems without needing live patients.

GLP-1 drugs are under investigation for treating Alzheimer's, Parkinson's, and drug addiction

Researchers are investigating GLP-1 applications for a variety of chronic conditions. One area of interest stems from how study participants using GLP-1 for diabetes and obesity reported describing less longing for wine and cigarettes while taking the medication—intriguing researchers about using the drugs for addiction applications. The drug, they theorize, could bind to receptors that mediate desire. (Some users may experience a paywall.)

In 2024, the US had more organ transplants than ever before—besting the 2023 record

More than 48,000 organ transplants were performed in 2024, and about 46,630 were performed in 2023. These record highs are illustrated here as part of data from 1988 to partway through 2025. Kidneys, livers, and the heart remain the most common transplanted organs. (Some users may encounter a paywall.)

GLP-1s are netting interest for treating autoimmune diseases, but are considered experimental

Already used to treat type 2 diabetes, the novel medications are showing some early promise in experimental studies at reducing inflammation and treating autoimmune conditions including rheumatoid arthritis and inflammatory bowel conditions. But researchers caution that side effects are still under investigation—rarely the medication has caused lupus, an autoimmune disease.

When was the first blood transfusion?

In the 1600s, an English doctor transferred the blood from one dog to another via quills. The procedure ended when one of the dogs died. This article details the early days of blood transfusions, which turned toward humans shortly after the 1666 dog experiment and involved putting the blood of a sheep into a human recipient (who reportedly survived the encounter).

‘Hope for Healing’: The first-ever use of an in utero stem cell treatment

In 2023, researchers at UC Davis performed the first-ever fetal stem cell transplant, attempting to cure a case of spinal bifida prior to childbirth using stem cells derived from the placenta. The trial, and others including an effort to treat muscular dystrophy, highlight the potential power of stem cell therapy.

A new type of immunotherapy focuses on healthy cells hijacked by tumors

Purdue University scientists are at work on a new cancer treatment that attacks immune system cells that feed and protect cancer cells rather than attacking them. The immunotherapy process promises to become a universal treatment for solid tumors. Thus far, the treatment has been tested and shown to work on human tumor cells in the laboratory and animal models.

Model organisms like yeast, mice, and flies help scientists decode the human body

Some species are used to quickly study the effects of human diseases and treatments because they are short-lived and have similar systems to those found in humans. Bacteria, like E. coli, have been used as human proxies given their rapid growth and ease of genetic manipulability.

Without the option of modern blood transfusions, some doctors in the mid-1800s tried to help save cholera patients by injecting them with cow's milk, hoping it would boost their nutrition and hydration.

Animal-to-human pathogens constitute 75% of emerging infectious diseases

Zoonotic diseases encompass more than 200 diseases transmitted from animals to humans, wherein humans are usually accidental hosts. Ranging from rabies to HIV to monkeypox, this overview lists some of the most common viral threats.

Scientists have created a cell from scratch—called a SpudCell—proof-of-concept work that a lab-made cell can feed, grow, and replicate like a natural cell.

NSF-funded research into matching algorithms improved the success of organ transplants

Investigations in game theory, including concepts focused on creating mutually beneficial partnerships—matching theory—led to the design of computer systems that efficiently matched kidney recipients and live donors, resulting in higher-quality matches. By 2019, these matching algorithms were used for multi-organ exchanges.

Stem cell therapies

Stem cells' special attributes interest researchers developing new therapeutic tools for a variety of health problems. Much of this research is done with support from the National Institutes of Health (NIH). This page offers a snapshot of research programs funded by the NIH and the health problems those programs focus on.

Organ transplants can come with a price tag of more than $2M without insurance

According to 2025 report data that was graphically represented by Statista, average costs for organ transplants can be as steep as $2.3M for a double lung transplant and $1.9M for a heart. These figures are based on what was actually charged to insurance companies—not what individual patients paid. Following the actual transplant there are also additional costs associated with the procedure, including lifelong immunosuppressant drugs.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

An overview of 200 years of diabetes treatment

Diabetes treatment became truly effective after the advent of insulin injections in the early 1900s. Diabetes is becoming increasingly common. Current trends estimate one in three Americans will have diabetes by 2050. This overview explores two centuries of diabetes treatment—starting in 1812—and outline potential challenges to treatment and prevention.