Pharmacological therapies

Insulin types, timing and hypoglycemia

How rapid, short, intermediate and long-acting insulins differ, when they peak, what can be mixed, and how to respond to low blood glucose.

7 min read·foundation·

Reviewed by a licensed nurse · 2 November 2026

Common insulin types

Type	Examples	Onset	Peak	Appearance
Rapid-acting	Lispro, aspart, glulisine	10 to 20 min	1 to 3 hours	Clear
Short-acting	Regular	30 to 60 min	2 to 4 hours	Clear
Intermediate	NPH	1 to 2 hours	4 to 12 hours	Cloudy
Long-acting	Glargine, detemir, degludec	1 to 2 hours	Minimal or none	Clear

Times are typical. Use the product labeling.

01
Roll the NPH
Gently roll the cloudy vial to mix it. Do not shake.
02
Inject air
Inject air equal to the dose into the NPH vial, then into the regular vial.
03
Draw clear first
Draw up the regular insulin first.
04
Draw cloudy second
Then draw up the NPH to the total dose. Clear before cloudy.

·Signs: sweating, tremor, hunger, confusion, palpitations, irritability.
·If alert and able to swallow: 15 g of fast-acting carbohydrate such as 4 oz of juice or glucose tablets.
·Recheck in 15 minutes. Repeat if below 70 mg/dL.
·If unable to swallow: glucagon or intravenous dextrose per the order, and call for help.
·Once normal, give a snack with protein if the next meal is not close.

·Rotate injection sites to prevent lipodystrophy.
·Do not massage the site after injection.
·Store unopened insulin in the refrigerator. In-use vials follow the labeled time.
·Illness can raise glucose, so insulin is not skipped without advice.

Check yourself

1. Which insulin may be given intravenously?
2. The nurse draws up regular and NPH insulin in one syringe. Which is drawn first?
3. A client has a glucose of 56 mg/dL and is alert. What is the next action?