Children require more insulin as they grow. Children's bodies are especially sensitive to the effects of insulin, making low glucose levels (hypoglycemia) more likely. This is a condition that often lasts until puberty. Children may require higher insulin use before puberty and maybe be able to lower the usage after puberty.

Insulin’s effect on elderly patients is similar to that of the medication’s effect on other adults. However, initial symptoms of low or high glucose (blood sugar) are not always as evident in older adults. This means it is easier for older adults to slip into hypoglycemia, or a state of low blood sugar.

In addition, older adults may have vision impairments or other health problems that make it more difficult for them to measure or inject medicine. Special training and equipment are available for patients in this age group.