The Nobel Prize in Physiology or Medicine

Randy Schekman bought his first microscope at the age of 12. In 2013, he became a medicine laureate.

About the prize

“The said interest shall be divided into five equal parts, which shall be apportioned as follows: /- – -/ one part to the person who shall have made the most important discovery within the domain of physiology or medicine …” (Excerpt from the will of Alfred Nobel)

Alfred Nobel had an active interest in medical research. Through Karolinska Institutet, he came into contact with Swedish physiologist Jöns Johansson around 1890. Johansson worked in Nobel’s laboratory in Sevran, France during a brief period the same year. Physiology or medicine was the third prize area Nobel mentioned in his will.

The Nobel Prize in Physiology or Medicine is awarded by the Nobel Assembly at Karolinska Institutet, Stockholm, Sweden.

See all medicine laureates or learn more about the nomination process.

Nobel Prize in Physiology or Medicine 2026

Light-seeking algae gave us a switch for nerve cells

To understand how the brain forms memories, feelings and behaviours has long been a dream for researchers. Karl Deisseroth, Peter Hegemann and Georg Nagel have been awarded the 2026 Nobel Prize in Physiology or Medicine for discoveries leading to optogenetics, which makes it possible to switch on, or off, the activity of individual nerve cells in a living brain. This method is now being used in laboratories around the world to reveal the brain’s mysteries.

Press release
Popular information: A light-sensitive algal protein energised neuroscience
Scientific background: Optogenetics. Discovery of a neuronal switch

An illustration of a woman playing chess, with a light switch connected to neurons in her brain. — © The Nobel Committee for Physiology or Medicine. Ill. Mattias Karlén

The 2026 medicine laureates

The Nobel Assembly at Karolinska Institutet has decided to award the 2026 Nobel Prize in Physiology or Medicine jointly to Karl Deisseroth, Peter Hegemann and Georg Nagel “for their discoveries concerning light-gated ion channels and optogenetics.”

Hegemann and Nagel discovered channelrhodopsin, a protein with unique properties. They found that regardless of which cell they put the protein in, those cells became light sensitive. Deisseroth introduced the gene for channelrhodopsin into nerve cells from rats. By illuminating the cells with blue light, he was able to trigger a nerve signal. Later, he made this light-controlled switch for nerve cells work in the brains of living mice.

This method for controlling nerve signals with light is now called optogenetics, and it has rapidly gained global impact.

Karl Deisseroth, Peter Hegemann and Georg Nagel — Ill. Niklas Elmehed © Nobel Prize Outreach

Did you know that light could be used to trigger individual nerve cells?

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3 discoveries that changed medicine

Nobel Prize in Physiology or Medicine 2008

HIV

Françoise Barré-Sinoussi and Luc Montagnier discovered the human immunodeficiency virus (HIV) in patients with swollen lymph glands, radically improving treatment methods for people with AIDS.

Scanning electron micrograph of HIV particles infecting a human H9 T cell.

NIAID/NIH, Public domain, via Wikimedia Commons

Nobel Prize in Physiology or Medicine 2023

mRNA vaccines

Katalin Karikó and Drew Weissman developed mRNA vaccines against COVID-19, contributing to the unprecedented rate of vaccine development during the pandemic.

Woman and man wearing lab shirts — Katalin Karikó and Drew Weissman.

Courtesy of Penn Medicine, Photography: Peggy Peterson

Nobel Prize in Physiology or Medicine 2005

Helicobacter pylori

Barry Marshall and Robin Warren worked together to discover that stomach ulcers are an infectious disease caused by a bacteria called helicobacter pylori.

Medicine prize Q&A

Nobel Prize in Physiology or Medicine: Behind the scenes

Learn more about how the Nobel Prize in Physiology or Medicine is decided and awarded in this interview with medicine prize awarder Juleen Zierath.

Juleen Zierath, professor of physiology

© Nobel Prize Outreach. Photo: Andrew Hart

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Who did what?

How many medicine laureates can you match?

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Questions and answers

What are the Nobel Prize categories?

The Nobel Prize categories are physics, chemistry, physiology or medicine, literature and peace and were laid out in the will of Alfred Nobel. Find out more in the FAQ.