Susan Leeman, 95, who isolated two neuropeptides, dies; legacy reshapes pain research

Susan E. Leeman, a pioneering endocrinologist whose laboratory isolated and chemically defined two neuropeptides, died on January 20, 2026, in New York City. She was 95. Leeman’s detection, sequencing and synthesis of Substance P and neurotensin, discoveries that the record credits with opening “fruitful fields of research for many investigators”, helped establish neuroendocrinology as a distinct discipline and left lasting implications for the study of pain, inflammation and brain-body signaling.

Born in Chicago on May 9, 1930, Leeman earned a B.A. from Goucher College in 1951 and an M.A. and Ph.D. from Radcliffe College in 1954 and 1958. Her doctoral thesis was titled The Problem of Neurohormonal Stimulation of the Secretion of Adrenocorticotropic Hormone. She joined Harvard Medical School in 1958 and held appointments at Brandeis University, the University of Massachusetts Medical School and, from 1992, Boston University School of Medicine, where she served as professor in the Department of Pharmacology and Experimental Therapeutics and later as director of the Neuropeptide Laboratory in the Pharmacology Department at the Chobanian and Avedisian School of Medicine. She continued to work into her nineties.

Her lab’s work was methodical and technical: after detecting “a sialogogic and a vasoactive substance in hypothalamic extracts,” researchers in her group isolated and defined the peptides, determined their amino acid sequences and synthesized them. As a Society for Neuroscience summary supplied for this account put it, “The determination of their amino acid sequences and the synthesis of these peptides have opened up fruitful fields of research for many investigators.” Her later laboratory goals included mapping the peptides’ distribution in brain and peripheral nervous system, delineating neuronal tracts that contain them, studying how they are released in vitro and in vivo, and identifying the binding domain of substance P with its receptor. Her recent work examined roles these peptides play in inflammatory responses of various tissues.

An obituary note filed alongside remembrances said, “In an era of overt sexism in the sciences, she made two major discoveries, including identifying a neuropeptide later linked to chronic pain syndromes and migraines.” That line points to the broader public health stakes of her career: peptide signaling underlies basic pathways of pain and immune modulation, areas that remain central to clinical efforts to treat chronic pain, reduce reliance on opioids and expand equitable access to effective therapies.

Leeman received numerous honors, including election to the American Academy of Arts and Sciences in 1987 and to the National Academy of Sciences in 1991, the FASEB Excellence in Science Award in 1993 and recognition as an AAAS Fellow in 2007. She delivered named lectures and held visiting professorships across the country, and she contributed a chapter to The History of Neuroscience in Autobiography, Volume 6.

Boston University’s Pharmacology, Physiology & Biophysics faculty posted a statement noting their sorrow and calling her work “pioneering,” and colleagues posted personal tributes. Valentina and Pietro recalled that Leeman “stood out, both as a colleague and a guiding light” and that “her rare courage in expressing dissent clearly and without fear, her intellectual integrity, and her refusal to compromise her values will be always remembered.” Hui Feng wrote to family that Leeman “was a mentor to all here in our department at Boston University” and that she inspired colleagues “to be critical of our findings and to make sure that everything we did was of the highest ethical value.”

Leeman’s science reshaped how clinicians and researchers think about the nervous system’s control over bodily processes, and her career, forged in a time of entrenched gender barriers, underscores ongoing conversations about equity in research, the importance of mentorship and the public health value of basic science that translates into new approaches to pain and inflammation.