The first follow-on drug (Basaglar) of the originator insulin glargine (Lantus), a long-acting insulin for treatment of type 1 and type 2 diabetes mellitus (T1DM, T2DM), was approved in 2015 in the United States. Information on the uptake, user characteristics, and outcomes of follow-on insulin remains sparse. To describe the utilization, user characteristics, and health outcomes of the follow-on insulin glargine and insulin glargine originators in a large, distributed network of primarily commercially insured patients in the United States. We used health care claims data in the US Food and Drug Administration's Sentinel common data model format across 5 research partners in the Biologics & Biosimilars Collective Intelligence Consortium distributed research network. Sentinel analytic tools were used to identify adult users of insulin glargine between January 1, 2011, and February 28, 2021, and describe patient demographics, baseline clinical characteristics, and adverse health events among users of the originators and the follow-on drug, stratified by diabetes type. We identified 508,438 users of originator drugs and 63,199 users of the follow-on drug. The proportions of the follow-on drug users among total insulin glargine users were 9.1% (n = 7,070) for T1DM and 11.4% (n=56,129) for T2DM. Follow-on use rose from 8.2% in 2017 to 24.8% in 2020, accompanied by a steady decrease in the use of originator drugs. Demographics of the users of the originators and follow-on drug were similar among the T1DM and T2DM groups. Overall, follow-on users had poorer baseline health profile and higher proportions of episodes with adverse events in the follow-up. We found evidence of increased uptake of the follow-on drug relative to the originator products in the post-2016 period. The differences in the base-line clinical characteristics between users of the originator products and the follow-on drug and their relationship with health outcomes merit further research. Sengwee Toh consults for Pfizer, Inc., and TriNetX, LLC. This study was funded by the BBCIC.