Obeid's research involved sphingolipids and their role in aging and cancer processes. She is considered a pioneer in the field of bioactive sphingolipids, and wrote or co-authored over 250 academic research articles and reviews. Among her many contributions was the first study documenting a role for ceramide in mediating apoptosis, and defining the roles of bioactive lipids in cell senescence. In 2019, Obeid (with Yusuf A. Hannun) received a Lifetime Achievement Award at the 16th International Conference on Bioactive Lipids in Cancer, Inflammation and Related Diseases. She was the first woman so honored by the conference. "It’s so important for emerging scientists – especially for young women considering a career in the sciences – to know they can make a difference in the field of cancer research," Obeid said, in receiving the award. Supporting her research laboratory, Obeid held both a Veteran Affairs Merit Award and a National Institutes of Health research grant for over two decades.