short-acting insulin, a clear preparation of regular (crystalline zinc) insulin with an immediate (15 to 30 minutes) onset of action that reaches a peak of action in 2 to 4 hours. The duration of action is 6 to 8 hours. There is considerable variation in individual patients and with different doses in the same patient. Therefore these data should be considered only as rough guidelines. Also called rapid-acting insulin. Compare intermediate-acting insulin, long-acting insulin. See also insulin.
