Insulin is used to treat Type 1 diabetes and Type 2 diabetes. It works by helping your body use glucose (sugar) for energy and storing excess glucose for future use. This helps to lower blood glucose levels. Most insulins are available in injectable forms. Examples include insulin glargine (Lantus, Semglee, Basaglar, Toujeo), insulin aspart (NovoLog, Fiasp), insulin lispro (Humalog, Admelog), and insulin degludec (Tresiba). You can discuss with your healthcare team which option might be right for you.