Which insulin type should be taken right before eating due to its quick onset?

Lispro insulin is a rapid-acting insulin that is designed to be taken immediately before eating, as it has a quick onset of action. This allows it to effectively manage postprandial (after meal) blood glucose spikes that can occur after eating. Because of its rapid absorption and action, it begins to lower blood glucose levels within about 15 minutes after administration, peaks in approximately 1-2 hours, and has a duration that can last up to 4-6 hours.

In contrast, regular insulin has a slower onset and works better when taken 30 minutes before a meal. NPH insulin is an intermediate-acting insulin that has a longer peak time and is not suitable for immediate pre-meal administration. Long-acting insulins have an extended duration and are meant for basal insulin control, making them unsuitable for immediate post-meal management. Therefore, lispro insulin is specifically formulated for the scenario of needing insulin right before meals.