Long-acting injectables (LAIs) have made a tremendous impact on clinical medicine. As evidence, dozens of approved LAI products are on the market. These LAI successes, in a large part, came from the clever chemistry of their materials that control drug delivery performance. Beyond their materials, what innovations and technologies led to LAI success? What were the scientific progressions and who were the people and their stories behind LAI success? What learnings are being translated to nano particles for drug delivery and treatment of new modalities? The answers to these questions are interesting to hear about, learn from, and be inspired by. Many people from many diverse fields contributed to the scientific advancement, product development and product launches of long-acting injectables. Over 50 years ago, LAI pioneers envisioned a host of new drug delivery concepts and engaged their enthusiasm to reduce their concepts to practice. In doing so, they considered a variety of materials, dosage forms, routes of administration, the biology, manufacturing processes and they had to devise new tools to support product development. Because of the wide technology breadth of long-acting injectables, this presentation will focus on bio absorbable LAIs formulated with polymeric excipients such as lactide/glycolide functional excipients. Their historical progression of polymer chemistry and formulation development is shared. Successes are highlighted with some backstories