Health & Medical

AI in Drug Discovery: How New Medicines Are Found

By Eri-Tech Global Ltd · Published November 3, 2026 · Last updated November 3, 2026 · 9 min read

Scientists in lab coats work with test tubes in a modern laboratory.
Scientists in lab coats work with test tubes in a modern laboratory.

AI in drug discovery is the use of computer models to help researchers find and shape new medicines. It does not replace the laboratory or the clinic. It works at the early stages, where researchers sort through far more biological data and chemical options than any team could check by hand.

A new medicine starts with a question about disease: which protein, gene, or pathway could be changed to help a patient? Once that target is chosen, researchers look for a molecule that acts on it in the right way, then test that molecule in the laboratory and, much later, in people.

This article explains that process in plain terms: what AI does well, where it still needs human checks, and what regulators in the United States and Europe now expect when AI is part of medicine development.

What drug discovery looked like before AI

Before AI tools became common, drug discovery followed a long, step-by-step path. Researchers first studied a disease to find a target, often a protein whose activity could be changed to improve health. Then they screened thousands of compounds, looking for the first "hits" — molecules that showed some effect on that target in laboratory tests.

The best hits were then refined into "leads." That refining step, called lead optimisation, adjusts a molecule to improve how strongly it binds to its target, how selective it is, and how it behaves in the body. Candidates that survived this work moved into preclinical testing, meaning laboratory and animal studies, and only then into clinical trials in people.

A recent review of AI in cancer drug development describes this full journey as taking 12 to 15 years, with most candidates failing along the way.

Computer-aided drug design already existed before modern AI. In the 1990s, researchers used computer models of drug-target interactions to guide laboratory work, rather than relying on trial and error alone. AI builds on that approach by learning patterns from large sets of biological and chemical data.

Finding a target: where a new medicine starts

Target identification is the first decision in drug discovery, and it shapes everything that follows. A target is a molecule or pathway in the body whose activity a medicine could change for a benefit. Choosing the wrong target can waste years, so researchers check many kinds of evidence before they commit.

AI helps here by pulling together different types of biological data. Genomic data shows which genes are changed in a disease. Transcriptomic data shows which genes are switched on. Proteomic and epigenomic data add information about proteins and how genes are regulated. The review of AI in cancer drug development describes models that read these combined data sets, rank disease-linked genes, and flag proteins that look most promising.

Protein shape matters because a protein's function depends on how its chain of amino acids folds into a three-dimensional form. If researchers know that shape, they can judge whether a molecule could fit and act on it. In 2020, Demis Hassabis and John Jumper presented AlphaFold2, an AI model that predicts protein structures from amino acid sequences. The Nobel Prize in Chemistry 2024 went to Hassabis and Jumper for protein structure prediction, with the other half of the prize going to David Baker for computational protein design.

The Nobel press release states that AlphaFold2 has been used to predict the structure of virtually all the 200 million proteins researchers have identified, and that it has been used by more than two million people from 190 countries. That shared library gives researchers a starting map, but a predicted shape still needs laboratory checks.

AI can also read published research, trial records, and patent data to find links between diseases, genes, and medicines that a single team might miss. The review gives the example of PandaOmics, a platform that combines multi-omics data with text mining to rank possible targets. These rankings are suggestions for researchers to test, not decisions made by the model alone.

Screening and designing molecules with AI

Once a target is chosen, researchers need molecules that might act on it. Two AI approaches help here. Virtual screening ranks existing chemical libraries by predicting which molecules are most likely to bind to the target. De novo design goes further: generative models propose entirely new molecular structures with chosen properties, rather than picking from a list that already exists.

The review describes how deep learning models predict drug-target interactions, screen millions of compounds, and optimise molecular features. One set of predictions covers ADMET properties: absorption, distribution, metabolism, excretion, and toxicity. In plain terms, that means how a substance enters the body, where it travels, how it is broken down, how it leaves, and whether it may cause harm. Predicting these properties early helps researchers set aside molecules that look unlikely to work as medicines.

Generative models can also propose changes to a lead molecule that might improve binding or reduce a predicted safety problem. Each proposal is then tested in the laboratory.

The review reports that more than 150 AI-designed small-molecule programmes were in preclinical development, with several already reaching clinical trials. That figure shows how far the field has moved from pure computer work into real testing. It does not mean those programmes will all succeed. Preclinical work and trials still remove most candidates, whether or not AI helped design them.

Scientist wearing a lab coat uses a microscope and pipette for research.
A scientist uses a microscope and pipette for research.

Why lab tests and clinical trials still come first

A computer prediction is only as good as the data behind it. The review lists the same limits that regulators raise: data quality, models that are hard to explain, computing demands, and questions about ethics and regulation. If training data are incomplete or biased, a model can favour the wrong targets or miss safety problems. If a model cannot explain its reasoning, researchers cannot easily check why it preferred one molecule over another.

That is why the testing stages after discovery have not changed in purpose. Preclinical work checks a candidate in cells and in animal studies before any person receives it. Then clinical trials test it in people, in phases that each answer a different question. The National Institutes of Health describes four phases. Phase I trials give an experimental treatment to a small group of 20 to 80 people for the first time, to judge safety and side effects. Phase II trials involve 100 to 300 people, to test effectiveness and to keep checking safety. Phase III trials involve 1,000 to 3,000 people, to confirm effectiveness, watch side effects, and compare the treatment with standard treatments. Phase IV trials take place after a medicine is approved, to track safety and best use over a longer period.

AI can also help inside trials, for example by helping researchers sort patient groups or plan studies, but it does not remove the need for these phases. Only trials, followed by regulator review, can show how a medicine acts in a large and varied group of people.

Readers should therefore treat news about AI medicines by their stage. A molecule found by a model, a candidate in animal studies, a candidate in a Phase I trial, and an approved medicine are four very different things, even if a headline treats them alike.

Detailed view of lab glassware with tubes and clamps in a laboratory setting.
Lab glassware with tubes and clamps in a laboratory.

What regulators now expect from AI in drug development

Regulators have moved from watching AI to setting out what they expect. The US Food and Drug Administration (FDA) says its Center for Drug Evaluation and Research has seen a large rise in drug application submissions that use AI components, across nonclinical, clinical, postmarketing, and manufacturing work. Its page on AI in drug development states that the agency's experience covers more than 500 submissions with AI components from 2016 to 2023.

The FDA published a discussion paper on AI and machine learning in drug development in May 2023, and a draft guidance in January 2025 on using AI to support regulatory decisions about a medicine's safety, effectiveness, or quality. The draft guidance asks sponsors to define the context of use, meaning the exact job the AI output is meant to do, and to show evidence matched to that job. The FDA also set up a CDER AI Council in 2024 to coordinate its AI work.

In Europe, the European Medicines Agency (EMA) adopted a reflection paper on AI in the medicinal product lifecycle in September 2024. The paper covers the full lifecycle, from drug discovery to the period after authorisation, and sets out considerations to help developers use AI in a safe and effective way. The EMA's overview page adds that the agency and the FDA have jointly identified ten principles for good AI practice in drug development, covering evidence generation and monitoring from early research through clinical trials, manufacturing, and safety monitoring.

The common thread is risk-based checking: the higher the patient risk or regulatory impact of an AI output, the stronger the evidence expected. Developers must document the training data, testing, ongoing performance checks, and where a person stays in charge of the final decision.

Frequently asked questions

Does AI design medicines on its own?

No. AI proposes targets and molecules and ranks options, but researchers choose which ideas to test, run the laboratory work, and judge the results. A model output is a suggestion that must survive experiments, trials, and regulator review before it can become a medicine.

Has AI already produced a medicine that patients can use?

AI-designed candidates have reached clinical trials, and more than 150 small-molecule programmes were reported in preclinical development in a recent review. Reaching a trial is not the same as approval. A medicine reaches patients only after trials show it is safe and effective and a regulator approves it.

Can AI make drug development faster?

It can speed up the early stages, by sorting targets and compounds faster than manual checks alone. The full path still includes laboratory testing, trials in people, and regulator review, so early speed does not remove the later stages or guarantee success.

AI in drug discovery is best understood as a better search tool for the hardest early questions: which target to pursue, which molecules deserve laboratory time, and which properties to check first. Its value shows when it helps researchers drop weak ideas early.

If you would like help turning a clear process into a simple system, explore our services or get in touch through our contact page.

This article is for general information and is not medical advice. Please speak to a qualified healthcare professional about your own situation.

What to watch next

Watch for the FDA's final guidance on AI in regulatory decision-making, for further EMA guidance following its reflection paper, and for trial results from AI-designed candidates now in clinical testing. Those three developments will show whether early AI gains hold up where it matters most: in people, under regulator review.

Sources

  1. FDA — Artificial Intelligence for Drug Development — date checked: 2026-11-03 — https://www.fda.gov/about-fda/center-drug-evaluation-and-research-cder/artificial-intelligence-drug-development
  2. European Medicines Agency — Use of Artificial Intelligence (AI) in the medicinal product lifecycle — date checked: 2026-11-03 — https://www.ema.europa.eu/en/scientific-guidelines/use-artificial-intelligence-ai-medicinal-product-lifecycle
  3. European Medicines Agency — Artificial intelligence — date checked: 2026-11-03 — https://www.ema.europa.eu/en/about-us/how-we-work/data-regulation-big-data-other-sources/artificial-intelligence
  4. Nature (npj Precision Oncology) — AI accelerate the identification of druggable targets by 3D structures of proteins and compounds — date checked: 2026-11-03 — https://www.nature.com/articles/s41698-026-01310-7
  5. National Institutes of Health — Glossary of Common Terms — date checked: 2026-11-03 — https://www.nih.gov/health-information/nih-clinical-research-trials-you/glossary-common-terms
  6. Nobel Prize — Press release: The Nobel Prize in Chemistry 2024 — date checked: 2026-11-03 — https://www.nobelprize.org/prizes/chemistry/2024/press-release/
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