How fast does Short insulin start working?

It usually starts lowering blood sugar within 30 minutes of injection.

When is the peak effect?

Peak effect occurs after about 3 hours.

How long does it last?

The total duration of action is around 7 hours.

Short-acting (Regular)

Short-acting (Regular) insulins start working within 30 minutes, peak around 2–4 hours, and last 6–8 hours. Usually injected 30 minutes before meals.

Onset

min

Fast

Time until it starts working after injection.

Peak

3 h

When effect is strongest (may be minimal for some long-acting insulins).

Duration

approx

Total time the insulin continues to act.

Activity curve (illustrative)

This stylized curve shows a typical onset, peak, and duration profile for Short insulins. For education only.

How it works

Short

Short-acting insulins are human insulins that start working around 30 minutes after injection. They peak at about 2–4 hours and continue to act for up to 6–8 hours.

Typical use

Typically injected 30 minutes before a meal. Often combined with an intermediate or long-acting insulin for full-day coverage.

Storage & handling

Keep refrigerated between 2–8°C until use. In-use vials or pens may remain at room temperature for up to 28 days if kept away from direct sunlight.

Frequently asked questions

When should I inject short-acting insulin in the meal-timing context?

What happens if I eat late after injecting this insulin?

Can short-acting insulin be mixed with other insulins in India?

How do injection site and rotation matter in the Indian setting?

Disclaimer: For educational purposes only. Always follow your healthcare provider’s dosing guidance.