Which of the following is a long-acting insulin analog?

• A. Glargine
• B. Regular
• C. NPH
• D. Lispro

Answer: (A)

Understanding long-acting insulin analogs helps you see why this option fits best. Long-acting insulin analogs are engineered to provide a steady, basal level of insulin with little to no pronounced peak, lasting about a day. Glargine is such an analog: after injection it forms a slow, gradual release that maintains near-constant insulin coverage over roughly 24 hours, with no sharp peak. This makes it ideal for basal (insulin background) control.

In contrast, regular insulin is a short-acting human insulin with a noticeable onset and a clearer peak, lasting around half a day. NPH is an intermediate-acting insulin, with a longer onset and a peak that produces a mid-day spike in insulin levels. Lispro is a rapid-acting insulin analog designed to act quickly to cover mealtime glucose rise, with a short duration.

So, the long-acting insulin analog among these is the one that provides a steady basal level throughout the day, which is glargine.