What is Genetically Modified Pork and How is it Made?

December 21, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), the first genetically modified pigs were approved for use in both food and medicine in December 2020. This milestone ushered in a new era of animal biotechnology, presenting questions about what is genetically modified pork, how it is created, and what it means for consumers and the food industry.

Quick Summary

Genetically modified pork is derived from pigs whose DNA has been intentionally altered, typically using gene-editing tools like CRISPR, to introduce desirable traits. Examples include resistance to viruses like PRRS and the removal of the alpha-gal sugar allergen.

Key Points

Gene Editing: Genetically modified pork is created by using advanced gene-editing techniques, most notably CRISPR-Cas9, to make precise changes to a pig's DNA.
Disease Resistance: A key application of this technology is the development of pigs that are resistant to devastating viral diseases, such as Porcine Reproductive and Respiratory Syndrome (PRRS).
Consumer Safety: The first GM pigs approved by the FDA, known as GalSafe pigs, are modified to eliminate the alpha-gal sugar, making their meat potentially safer for those with alpha-gal syndrome, a meat allergy.
Biomedical Applications: GalSafe pigs also serve a critical medical purpose by providing organs, tissues, and products, like heparin, that are less likely to be rejected during xenotransplantation.
Regulatory Oversight: GM animals intended for food and medical use undergo stringent regulatory review, and the FDA has determined that approved GM pork is as safe and nutritious as conventional pork.
Ethical Considerations: The use of genetic modification in animals raises ethical debates regarding animal welfare, potential environmental impacts, and the long-term effects of altering animal genomes.

The Science Behind Genetically Modified Pork

Genetically modified (GM) pork is created by intentionally altering the DNA of pigs to produce specific, beneficial traits. This process leverages advanced genetic engineering tools that enable scientists to add, remove, or modify genes with high precision. This stands in contrast to traditional selective breeding, which relies on gradual, natural genetic changes over many generations to achieve desired outcomes. The techniques used to produce GM pork are far more directed, allowing for quicker and more predictable results.

Gene-Editing Technologies

Several methods are used to create genetically modified pigs, with the modern approach centered on precise gene-editing technologies.

CRISPR-Cas9: This is one of the most widely used gene-editing tools for creating GM pigs. CRISPR, short for 'Clustered Regularly Interspaced Short Palindromic Repeats,' along with the Cas9 enzyme, acts like a molecular scissors to make targeted changes to an organism's DNA. For example, scientists have used CRISPR to remove a gene that allows the porcine reproductive and respiratory syndrome virus (PRRSV) to infect pigs, making them resistant to the disease.
Somatic Cell Nuclear Transfer (SCNT): This older method involves transferring the nucleus of a genetically modified somatic cell (a non-reproductive cell) into an enucleated egg cell, which is then implanted into a surrogate mother. The resulting offspring is a clone of the animal that provided the somatic cell and carries the intended genetic modification.
Pronuclear Microinjection: In this technique, foreign DNA is directly injected into the nucleus of a fertilized egg. This method often results in random integration of the new gene, making it less precise than CRISPR, but it was historically one of the primary methods for creating transgenic animals.

Agricultural and Medical Applications

The development of genetically modified pigs serves several purposes, ranging from improving agricultural efficiency to advancing human medicine.

Agricultural Benefits:

Disease Resistance: A major driver for GM pork is the creation of pigs resistant to devastating viral diseases like PRRSV. This helps reduce animal suffering, lower economic losses for farmers, and potentially decrease the need for antibiotics to treat secondary infections.
Enhanced Nutrition and Growth: Some GM pigs have been developed to have leaner meat by editing genes related to fat metabolism. Other early efforts focused on faster growth rates, though some of these experiments showed unintended health side effects.
Improved Feed Efficiency and Environmental Impact: The 'Enviropig' was an example of a GM pig that had been engineered to better digest phosphorus from its food, leading to less phosphorus pollution in its manure.

Biomedical Benefits:

Xenotransplantation: This involves transplanting organs or tissues from animals into humans. GalSafe pigs, for example, were developed to eliminate the alpha-gal sugar on their cells, which can trigger immune rejection in humans. Their organs may be used for human transplantation.
Pharmaceutical Production: GM pigs can be engineered to produce human medical products, such as an alpha-gal-free version of the blood-thinning drug heparin.

Regulation and Market Acceptance

The regulatory landscape for GM animals is a complex and evolving area. In the U.S., the FDA regulates GM animals as new animal drugs, requiring extensive safety and environmental assessments before approval. The approval of GalSafe pigs for human consumption and medical use by the FDA marked a significant step in the process. However, acceptance by consumers remains varied, influenced by differing ethical and safety concerns. Transparency and clear labeling can help consumers make informed choices about bioengineered foods.

Comparison: GalSafe Pigs vs. AquAdvantage Salmon


Feature	GalSafe Pig	AquAdvantage Salmon
Genetic Modification	Removal of the alpha-gal sugar gene to prevent allergic reactions in some people and enable xenotransplantation.	Insertion of a gene to accelerate growth rate by ensuring year-round production of growth hormone.
Regulatory Approval	FDA approved for both human consumption and medical use in December 2020.	FDA approved for human consumption in 2015, after a multi-decade review process.
Key Benefit	Produces alpha-gal-free meat, organs for transplantation, and pharmaceuticals.	Reaches market size in about half the time of conventional salmon, using less feed.
Status in the Food Chain	The developer, Revivicor, initially planned to sell pork through a delivery service.	Now available for sale to consumers in the U.S. and Canada.
Environmental Controls	Strict containment conditions to prevent escape.	Produced in secure, land-based aquaculture facilities to prevent interbreeding with wild salmon.

Potential Risks and Ethical Concerns

Despite the potential benefits, genetically modifying animals for food and medicine also raises important questions about unintended health consequences, environmental risks, and animal welfare. Accidental release of GM animals into the wild could affect biodiversity and ecosystem stability. While regulatory bodies attempt to mitigate these risks, public debate continues regarding the long-term impact. Ethical concerns about altering animal genetics and the treatment of GM animals during production are also part of the broader conversation.

The Path Forward for Genetically Modified Pork

The future of genetically modified pork is likely to involve more targeted and precise modifications, driven by advances in gene-editing technology like CRISPR. As regulatory processes continue to adapt and public understanding grows, the availability of GM pork and other animal products for consumption could increase. Ultimately, the trajectory will be shaped by a balance of scientific innovation, stringent safety and environmental assessments, and consumer perception. The ongoing development of disease-resistant pigs is a prime example of an application that addresses significant industry challenges and improves animal welfare.

In conclusion, genetically modified pork is no longer a theoretical concept but a tangible product of modern biotechnology, with specific examples like GalSafe pigs having received regulatory approval. While the potential benefits for agriculture and medicine are significant, ongoing public and scientific dialogue is crucial to address the associated risks and ethical considerations.

Visit the FDA's page on Agricultural Biotechnology for more information.

Frequently Asked Questions

Yes, regulatory bodies like the U.S. Food and Drug Administration (FDA) have conducted extensive safety reviews and determined that food from approved genetically modified pigs, such as GalSafe pigs, is safe for general consumption.

Genetically modified pork involves intentional, targeted alterations to a pig's DNA using modern genetic engineering tools. Organic pork, on the other hand, is raised according to a specific set of standards that prohibit the use of genetically engineered ingredients, antibiotics, and certain pesticides, relying instead on traditional breeding.

The primary agricultural benefit is the development of disease-resistant pigs. Scientists have created pigs resistant to costly and harmful diseases like PRRS, which improves animal welfare and reduces economic losses for producers.

GalSafe pigs were created specifically to remove the alpha-gal sugar allergen, and their meat is potentially safe for those with the allergy. However, the FDA notes that the meat was not specifically reviewed for allergen safety when consumed by someone with an alpha-gal allergy, and individuals should consult a physician.

Genetically modified pigs, such as GalSafe pigs, can be used to produce medical products that are free of the alpha-gal sugar. This includes pharmaceuticals like the blood-thinner heparin and potentially organs or tissues for xenotransplantation.

Labeling requirements for bioengineered foods vary by country. In the U.S., under the National Bioengineered Food Disclosure Standard, foods with detectable bioengineered DNA must carry a label. This means that some GM pork products may be labeled as bioengineered.

Gene-editing techniques like CRISPR offer far more precision than older methods like random DNA insertion via pronuclear microinjection. CRISPR allows scientists to make targeted, specific changes, which can be no different from naturally occurring genetic mutations.