Genetically modified organism

A genetically modified organism, or GMO, is a plant, animal, or microorganism whose genetic material has been altered using laboratory techniques, typically to introduce a specific trait such as pest resistance, herbicide tolerance, or improved nutritional content, in a more targeted and often faster way than conventional selective breeding allows. While humans have altered the genetics of crops and livestock for thousands of years through selective breeding, the term GMO specifically refers to organisms modified through modern genetic engineering techniques developed from the 1970s onward.

How genetic modification works

Genetic engineers typically introduce a gene from one organism into another to confer a specific trait the recipient organism does not naturally have, a process called transgenesis when the inserted gene comes from a different species. Classic examples include inserting a gene from the soil bacterium Bacillus thuringiensis into corn or cotton to make the plant produce a protein toxic to certain insect pests, reducing the need for sprayed pesticides, or inserting genes that make a crop tolerant of a specific herbicide, letting farmers spray that herbicide on their fields without damaging the crop itself while still controlling weeds. More recent gene-editing techniques, including CRISPR, can alter an organism’s own existing genes directly, for example disabling a gene responsible for a trait breeders want to remove, without necessarily introducing DNA from an entirely different species, a distinction that has led some regulators to treat certain gene-edited crops differently from older-style transgenic GMOs under their existing rules.

Major GMO crops and traits

Soybeans, corn, cotton, and canola account for the large majority of genetically modified crop area planted worldwide, with pest-resistant and herbicide-tolerant traits, often combined in the same plant, dominating commercial adoption so far. Global GM crop area reached a record of roughly 210 million hectares in 2024, according to industry tracking cited by agricultural trade publications, with the United States, Brazil, and Argentina together accounting for the large majority of that area and soybeans alone making up close to half of the global total. Beyond these dominant commodity crops, newer approved varieties have moved toward direct consumer nutritional benefits, including golden rice, engineered to produce beta-carotene, a precursor to vitamin A, aimed at addressing vitamin A deficiency in parts of the world where rice is a dominant staple food.

Regulation and global adoption

Regulatory approaches to GMOs differ sharply around the world. The United States generally regulates genetically modified crops similarly to their conventional counterparts once specific safety reviews are passed, reflecting a regulatory philosophy focused on the resulting product’s characteristics rather than the genetic modification process itself. The European Union takes a markedly more cautious, process-focused approach, requiring specific authorization and labeling for genetically modified food products and maintaining far lower commercial cultivation of GM crops within its borders compared with the Americas, even though it does permit imports of some GM commodities for animal feed. Dozens of countries approve new GM crop varieties each year, 28 of them in 2024 alone according to industry tracking, reflecting steadily, if unevenly, expanding global regulatory acceptance even as public opinion and specific national rules continue to vary considerably.

Safety and public debate

Major scientific and regulatory bodies that have reviewed currently approved GM crops, including national academies of science in multiple countries, have generally concluded that approved GM foods pose no greater health risk to consumers than their conventional counterparts, based on the specific traits and safety testing those crops have undergone. Public debate over GMOs nonetheless persists, often centering less on acute consumer safety and more on ecological concerns, such as the potential for herbicide-tolerant crops to encourage greater overall herbicide use or for engineered genes to spread into wild relatives of a crop, and on broader questions about corporate control of the seed supply and the economic position of farmers relative to the small number of companies that develop and patent most commercial GM seed varieties.

GMOs versus organic farming

Genetically modified organisms and organic farming sit at nearly opposite ends of a regulatory spectrum: certified organic standards in most major markets specifically exclude genetically modified inputs, treating avoidance of genetic engineering as one of organic farming‘s defining features alongside its restrictions on most synthetic fertilizers and pesticides. This makes GMO status one of the clearest, most consistently enforced dividing lines between conventional and certified organic agricultural products, even though the two categories, genetically modified and organic, address somewhat different aspects of how a crop is produced.

Labeling and consumer choice

Food labeling requirements for genetically modified ingredients vary as widely as cultivation rules do. The United States adopted the National Bioengineered Food Disclosure Standard, which took full effect at the start of 2022 and requires many packaged foods containing detectable modified genetic material to carry a “bioengineered food” disclosure, using that specific regulatory term rather than the more common “GMO” label consumers often look for. The European Union requires clearer, more prominent labeling of genetically modified ingredients on finished food products sold to consumers, consistent with its broader process-focused regulatory stance, while a number of other countries fall between these two approaches or exempt certain categories, such as highly refined oils or sugars derived from GM crops that no longer contain detectable modified DNA. For shoppers trying to avoid genetically modified ingredients specifically, independent non-GMO certification labels, separate from organic certification, exist in several markets as an additional point of reference beyond government-mandated disclosure.

FAQs

Is gene editing the same thing as older-style genetic modification? Not exactly. Classic genetic engineering often inserts a gene from a different species into the target organism, while newer gene-editing techniques such as CRISPR can alter an organism’s own existing genes directly without necessarily introducing foreign DNA, a distinction some regulators now treat differently under their existing GMO rules.

Do major scientific bodies consider approved GM foods unsafe to eat? No. National academies of science and other major regulatory and scientific bodies that have reviewed currently approved GM crops have generally concluded they pose no greater health risk to consumers than their conventional counterparts, though public debate over GMOs often centers on other ecological and economic concerns rather than acute consumer safety.

This entry explains a medical term. It is not medical advice. If you are concerned about your health, speak with a qualified health professional.

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 1, 2026Researched and drafted with AI assistanceReport an issue