'Korea is the cruelest': Nearly 5 million animals used in experiments last year, half in extreme pain

About 5 million animals are sacrificed in South Korea alone each year.

A monkey, limbs restrained, shifts anxiously. At first glance it might look like a medical procedure — but it is the opposite.

The animal is being used in an experiment in which narcotics are injected to test brain responses.

Monkeys are far from the only subjects. Dogs, cats, rats, rabbits, birds and even fish are among the countless species pressed into service across a vast range of experiments.

South Korea is no exception. About 5 million animals were used in experiments in the country last year alone.

More than half of those animals were subjected to experiments involving unavoidable severe pain.

The technological and academic advances made possible by animal testing — and the consumer benefits that have followed — cannot be dismissed.

The problem, critics say, is that unnecessary experiments continue out of entrenched habit, and that South Korea is falling behind advanced nations in Europe and elsewhere in shifting to alternative testing methods and tightening regulation of animal experiments.

An analysis of annual data on the operation of institutional animal care and use committees published by the Animal and Plant Quarantine Agency shows that the number of laboratory animals in South Korea rose from about 2.5 million in 2015 to about 4.95 million in 2025 — an increase of roughly 2.45 million animals, or 97.6%, effectively doubling over the decade.

The number of laboratory animals peaked at about 4.99 million in 2022 before falling to about 4.58 million in 2023, but has risen again over the past two years. Converted to a daily figure, last year's total works out to 13,572 animals — meaning more than 10,000 laboratory animals are used every single day.

Rodents are by far the most commonly used animals. Of the approximately 4.95 million animals recorded in 2025, mice, rats and other rodents accounted for about 4.13 million, or 83.3% of the total. Other mammals — including dogs, cats, pigs and cattle — numbered 88,498 (1.8%), while rabbits accounted for 25,499 and monkeys for 4,142.

A particularly troubling trend is the growing share of animals used in Grade E experiments — the highest pain category. South Korea classifies animal experiments on a scale from B to E based on the degree of suffering involved. Grade E covers procedures that cause severe pain or unavoidable stress, including experiments where adequate analgesia or anesthesia cannot be applied for scientific reasons, or where the animal's death is the designated endpoint.

The number of animals used in Grade E experiments surged from about 750,000 in 2015 to about 2.61 million in 2025 — an increase of roughly 1.86 million, or 247.7%, far outpacing the overall growth rate of 97% for all laboratory animals. Grade E animals as a share of the total also climbed from 30.0% in 2015 to 52.7% last year, a record high.

South Korea's trajectory stands in sharp contrast to trends in some advanced nations, including the United Kingdom, EU member states and the United States, where both the overall scale of animal testing and the use of the highest-pain procedures are declining. Those countries are also accelerating regulatory reforms and the adoption of alternative testing methods to reduce animal experiments.

According to the "Annual Statistics of Scientific Procedures on Living Animals in Great Britain 2025," published by the UK Home Office on July 9, the number of animal testing procedures in the country last year totaled about 2.54 million — down roughly 38.6% from the 2015 peak of about 4.14 million, and the lowest figure recorded since 1986.

Among all procedures, those conducted for actual experimental purposes also hit a record low last year at about 1.32 million. The share rated at the highest severity level fell from 3.4% in 2024 to 1.3% last year.

A report released by the European Commission on March 31 this year showed that animal use across the EU's 27 member states and Norway fell 10.1%, from about 8.98 million cases in 2018 to about 8.08 million in 2023. Use in the highest-pain category dropped 28.0% over the same period.

Direct comparisons between national figures have their limits. South Korea counts the number of individual animals used, while the United Kingdom counts procedures — meaning a single animal used more than once is recorded as multiple procedures. The EU and UK also conduct retrospective assessments of the pain animals actually experienced, whereas South Korea's Grade E classification is assigned at the planning stage based on anticipated pain levels and the feasibility of administering analgesics.

Even so, the directional contrast within the data is stark. In South Korea, both overall animal use and Grade E use have risen together, while in the UK and EU, total experimental procedures have fallen and use of the highest-pain category has declined.

Critics say South Korea needs to move faster on related policy. Overseas, regulatory reforms aimed at replacing animal testing are already gaining momentum.

The US Environmental Protection Agency formally reaffirmed in January its goal to effectively eliminate all mammalian animal testing it requests or funds by 2035. In June, the agency expanded its list of non-animal alternative testing methods available for chemical safety assessments and streamlined the process for incorporating new alternatives into regulation.

The European Commission adopted a formal roadmap in June to phase out animal testing in safety assessments for industrial chemicals, pharmaceuticals and food additives.

The South Korean government formed an inter-agency consultative body in October last year. The Ministry of Climate, Environment and Energy launched a joint public-private task force in May and announced plans to develop a strategy for promoting non-animal alternative testing methods for chemicals between 2027 and 2035, along with measures to gradually restrict animal testing. However, a concrete roadmap with specific reduction and replacement timelines for individual test types — comparable to those seen abroad — has yet to be established.

A representative of the Korea Animal Protection Association said that in other countries, the ethical and scientific shortcomings of animal testing have become a major social debate, with efforts to reduce it in full swing. "Animal experiments in South Korea are not decreasing — in fact, experiments rated at pain grades D and E now account for 80% of the total, presenting a deeply distorted picture," the representative said.