Drucker was funded by a Medical Research Council of Canada Centennial Fellowship to study molecular endocrinology with Professor Joel Habener.

[5] Drucker, together with colleagues at Tufts Universities, filed multiple patents describing the utility of targeting the DPP-4 enzyme, and published studied demonstrating that genetic or chemical inactivation of DPP-4 prevented degradation of GLP-1 and GIP, supporting the development of DPP-4 inhibitors for the treatment of type 2 diabetes.

[10][11] Collectively, the body of work from multiple investigators and companies led to the development of two leading classes of diabetes medications: GLP-1 receptor agonists and DPP4 inhibitors.

[12] In 1996, he also discovered the effects the first biological actions for GLP-2, demonstrating that GLP-2 augmented crypt cell proliferation and expansion of the mucosal epithelium in the small bowel of mice and rats.

[13] He subsequently identified and characterized a DPP-4-resistant molecule, teduglutide,[14] that was ultimately developed and approved for the treatment of short bowel syndrome in adults and children, a disorder in which fluids are poorly absorbed after resection of the small intestine.

Drucker has received many national and international awards in recognition of his research accomplishments revealing the mechanisms of action and therapeutic potential of enteroendocrine hormones.