Botanical Safety Consortium Steering Committee


Cynthia Rider, PhD

Toxicologist, National Toxicology Program (NTP), National Institute of Environmental Health Sciences (NIEHS)

Cynthia serves as a project leader for testing programs including botanical dietary supplements. Her research focuses on evaluating and refining methods to predict mixture toxicity based on data from components or whole reference mixtures. She can be contacted at

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Hellen Oketch-Rabah, PhD

Deputy Director, Office of Dietary Supplement Programs (ODSP), Center for Food Safety and Applied Nutrition, Food & Drug Administration (FDA)

Dr. Oketch-Rabah joined CFSAN in June 2023. Prior to joining ODSP she was at the United States Pharmacopeia (USP) from 2011 in different roles in the Dietary Supplements and Herbal Medicines Department, developing dietary supplements quality monographs. Before that, she was the Principal Scientist at Herb Pharm Inc., a dietary supplement manufacturing facility in Oregon. Dr. Oketch-Rabah did her Post-Doc at the Lawrence Berkeley National Laboratory in California on breast cancer biology and phytochemicals for treatment of postmenopausal symptoms. Earlier in her career, she was an assistant Professor of Pharmacognosy at the School of Pharmacy, University of Nairobi, Kenya. Dr. Oketch-Rabah earned her Ph.D. in Pharmacognosy/ Medicinal Chemistry from the Royal Danish School of Pharmacy (University of Copenhagen) working on Kenyan Medicinal Plants with antimalarial and antileishmanial properties.

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Michelle Embry, PhD

Associate Director, Environmental Science, Health and Environmental Sciences Institute (HESI)

Michelle is the Associate Director of HESI, where she provides leadership, technical direction, and guidance to varied, multi-stakeholder, collaborative committees on topics related to risk assessment and environmental protection worldwide. She can be contacted at

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Bill J. Gurley, PhD

Professor and Principal Scientist at the National Center for Natural Products Research (NCNPR), School of Pharmacy, University of Mississippi

Dr. Gurley spent three decades conducting vital basic and clinical research on dietary supplement safety and efficacy. Notably, his research played a pivotal role in the FDA's removal of Ephedra-containing supplements from the U.S. market in 2004. Dr. Gurley was a trailblazer in assessing herb-drug interactions, notably shedding light on St. John's wort's clinical implications. His extensive work has culminated in 200+ peer-reviewed scientific publications. He contributes actively to the field as a member of the United States Pharmacopoeia's Expert Panel on Dietary Supplements and an advisor to the American Botanical Council. Dr. Gurley's editorial roles include sitting on the boards of Clinical Pharmacology & Therapeutics, Phytomedicine, HerbalGram, and Clinical Therapeutics. He holds degrees from Tennessee Technological University and the University of Tennessee Health Science Center.

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Holly Johnson, PhD

Chief Science Officer, American Herbal Products Association

Holly has over 20 years experience in botanicals research as a pharmacognosist with a specialization in medical ethnobotany. She is the chief science officer for the American Herbal Products Association, an alliance of over 350 companies doing business in the natural products industry. She can be contacted at

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Olaf Kelber, PhD

Senior Science Fellow, R&D Phytomedicines, Bayer Phytomedicines Supply and Development Center

Olaf is working as a scientist in R&D of phytomedicines and natural products. Biologist by training, with a specialization in toxicology, he has long standing experience also in pharmacology and clinical research on phytomedicines and is active in scientific societies in the field of natural products, and is e.g. secretary of the leading global society for natural product research, GA, and member of the scientific EWG of Kooperation Phytopharmaka. He can be contacted at



Julie Krzykwa, PhD

Scientific Program Manager, Health and Environmental Sciences Institute (HESI)

Julie works on the Botanical Safety Consortium and other scientific committees at HESI to develop science for a safer, more sustainable world. She can be contacted at


Jacob Larson, MPH, DABT 

Senior Research Scientist, Toxicology | Global Product Science & Safety

Jacob Larson currently holds the position of Senior Research Scientist, Toxicology at Herbalife. He received his Master’s degree in Public Health, Toxicology from the University of Michigan and worked for 15 years as a toxicologist at NSF International in the drinking water chemical and dietary supplement certification areas before joining Herbalife in 2020. He is a board-certified toxicologist, a member of the Society of Toxicology, and a member of the Johns Hopkins Center for Alternatives to Animal Testing (CAAT) Advisory Board. Jacob is also a member of the DART BSC working group.


Connie Mitchell, MS

Scientific Program Manager, Health and Environmental Sciences Institute (HESI)

Connie works on the Botanical Safety Consortium and other scientific committees at HESI to develop science for a safer, more sustainable world. She can be contacted at

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Amy L Roe, PhD, DABT, FATS

Director Principal Toxicologist, Personal Health Care, The Proctor & Gamble Company

Amy is currently the technical lead regulatory toxicologist for P&G Personal Health Care, North America and Latin America Regions. She provides safety support across OTC drugs, medical devices, herbal/dietary supplements, probiotics and food products. She is a current member of the USP Dietary Supplement Admission Evaluation & Labeling Expert Committee and Probiotic Expert Panel. A Full Member of the Society of Toxicology, she current serves as Vice-President of the Food Safety Specialty Section. Amy is also a member of the Hepatotoxicity/ADME BSC working group.