Marilyn Huestis, PhD

Senior Advisor, Clinical Pharmacology and Toxicology, Cannabinoid and Other CNS-Active Pharmacotherapies

Applying excellence in clinical and forensic toxicology to CNS-active drug and compound development and regulatory pathways


With an extensive and well-recognized career in research on psychoactive substances, Marilyn shares with clients an exceptional mastery of:

  • Clinical and forensic toxicology
  • Diagnostic screening and confirmation drug testing


Marilyn conducted human drug administration studies for 23 years before retiring from the National Institute on Drug Abuse, where she was a tenured senior investigator and chief of the section of Chemistry and Drug Metabolism of the Intramural Research Program.

She is a senior fellow at the Institute on Emerging Health Professions, Thomas Jefferson University; Honorary Professor at Barts and the London School of Medicine and Dentistry, Queen Mary University of London; member of the Smart Approaches to Marijuana Science Advisory Board; and president of Huestis & Smith Toxicology, LLC.

Marilyn has published more than 500 peer-reviewed publications and book chapters, and has had more than 800 abstracts presented at meetings worldwide. Her recent honors include the Distinguished Service to Safety Award, National Safety Council (2021); the American Association of Clinical Chemistry’s Outstanding Lifetime Achievement Award (2021); the Alexander O. Gettler Award, Toxicology Section, American Academy of Forensic Sciences (2021); the Lyons-Voorhees Endowed Lectureship at the University of Colorado Medical School Department of Psychiatry, Aurora, Colo. (2019); the Robert F. Borkenstein Award, National Safety Council (2018); the Marian W. Fischman Lectureship Award, College on Problems of Drug Dependence (2016); and Distinguished Fellow, American Academy of Forensic Sciences (2015).

The journal Clinical Chemistry has featured Marilyn in its “Inspiring Minds” series of essays.


  • MD honoris causa, Faculty of Medicine, University of Helsinki, Finland
  • PhD with honors, Toxicology, University of Maryland
  • MS with honors, Clinical Chemistry, University of New Mexico
  • BS cum laude, Biochemistry, Mount Holyoke College

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