Answered 1/15/2014 by Samuel Grossman, BS Pharm, Pharm.D, CDE
Regular insulin u-500 is 5 times more potent than the Regular insulin u-100 that is dispensed in pharmacies. U-500 is not better or worst than u-100, it is just a different kind of insulin. Some patients may benefit from a u-500 insulin, especially individuals with significant insulin resistance. The onset of action of Regular insulin U-500 insulin is similar to Regular insulin U-100. However, the duration of action of u-500 insulin is longer than insulin u-100.