Henri B. Kagan and Kenso Soai Win Chemistry Nobel for Life’s Asymmetry

What changed

Henri B. Kagan and Kenso Soai have won the 2026 Nobel Prize in Chemistry for explaining how nature produces one preferred form of a molecule rather than its mirror image.

The prize recognises work built over decades: Kagan created an excess of one molecular form in 1986, Soai reported a potentially homochiral reaction in 1995, and in 2003 controlled a reaction that produced only one mirror form. They will share 12 million Swedish kronor.

Why it matters

Molecules can be mirror images of each other, much like left and right hands. They may look nearly identical, but the body can treat them very differently.

That matters most sharply in medicine. One version of a molecule may fight disease while its twin does little or causes harm. Thalidomide became the grim example: the drug was given as a mixture, and thousands of children were born with severe disabilities after their mothers took it during pregnancy.

Kagan and Soai showed how chemists can push reactions toward the desired molecular version instead of accepting the usual 50-50 mixture. That gives drug designers a much tighter grip on what they are making, and on which form reaches the body.

The bigger achievement is conceptual as well as practical. Life overwhelmingly uses one handedness of key molecules, while ordinary laboratory chemistry tends to make both. Their work explains how that imbalance can emerge and be controlled in the laboratory.

The next question is timing. The award recognises a powerful chemical method, but it does not establish when those methods will produce commercially available medicines or other products.