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.

© Nobel Prize Outreach. Photo: Alexander Mahmoud

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 2025

The body’s powerful immune system must be regulated, or it may attack our own organs. Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi made groundbreaking discoveries concerning peripheral immune tolerance that prevents the immune system from harming the body. Their discoveries have laid the foundation for a new field of research and spurred the development of new treatments, for example for cancer and autoimmune diseases.

Press release
Popular information: They understood how the immune system is kept in check
Scientific background: Immune tolerance: The identification of regulatory T cells and FOXP3

Nobel Prize in Physiology or Medicine 2025

© The Nobel Committee for Physiology or Medicine. Ill. Mattias Karlén

The Nobel Assembly at the Karolinska Institutet has decided to award the 2025 Nobel Prize in Physiology or Medicine to Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi “for their discoveries concerning peripheral immune tolerance.”

They identified the immune system’s security guards, regulatory T cells, thus laying the foundation for a new field of research. The discoveries have also led to the development of potential medical treatments that are now being evaluated in clinical trials. The hope is to be able to treat or cure autoimmune diseases, provide more effective cancer treatments and prevent serious complications after stem cell transplants.

The medicine laureates 2025

Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi

Ill. Niklas Elmehed © Nobel Prize Outreach

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3 discoveries that changed medicine

Nobel Prize in Physiology or Medicine 2008

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.

HIV-infected_H9_T_cell2.jpg

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

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

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

An illustration of helicobacter pylori

An illustration of helicobacter pylori.

iLexx via Getty Images

Medicine prize Q&A

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

Juleen Zierath, professor of physiology

© Nobel Prize Outreach. Photo: Andrew Hart

Who did what?

Questions and answers

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.

The Nobel Prize medal.

The Nobel Prize medal.

© Nobel Prize Outreach. Photo: Clément Morin.

Nobel Prizes and laureates

The microscope that medicine laureate Ralph Steinman used daily.

© Nobel Media. Photo: Alexander Mahmoud

Explore and learn

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How do we know where we are? How can we find the way from one place to another? Thanks to the discovery of the brain’s “inner GPS” we now have a better understanding for how we manage to orient ourselves in space.

May-Britt Moser in the laboratory

Laureate May-Britt Moser in the laboratory

Photo: Geir Mo

Tu Youyou scoured ancient literature on herbal medicine in her quest to develop novel malaria therapies. A key insight into how to preserve the active ingredient during processing led to the discovery of artemisinin, which has saved many lives.

Tu Youyou

Tu Youyou, Nobel Prize in Physiology or Medicine 2015.

© Nobel Prize Outreach. Photo: Alexander Mahmoud

Follow how the discoveries Yoshinori Ohsumi made in baker’s yeast led to a new understanding of how our own cells recycle their contents. Autophagy, or ‘self-eating’ refers to the way our cells can degrade and then re-use their own contents.

Dragon ohsumi

Illustration depicting autophagy

Image: The Nobel Assembly at Karolinska Institutet