Insulin lispro, sold under the brand name Humalog among others, is a modified type of medical insulin used to treat type 1 and type 2 diabetes. It is delivered subcutaneously either by injection or from an insulin pump. Onset of effects typically occurs within 30 minutes and lasts about 5 hours. Often a longer-acting insulin like insulin NPH is also needed.
Common side effects include low blood sugar. Other serious side effects may include low blood potassium. Use in pregnancy and breastfeeding is generally safe.