Understanding the different types of insulin is essential for nursing exams and clinical practice. Whether you’re studying for the NCLEX or preparing for med-surg exams, you must know:
- The specific medication names
- Their onset
- Their peak
- Their duration
- Key safety considerations
Let’s break it down in a clear, exam-focused way.
What Do Onset, Peak, and Duration Mean?
Before diving into the insulin types, make sure you understand these core concepts:
- Onset – When the insulin starts working
- Peak – When insulin works at its strongest (highest risk for hypoglycemia)
- Duration – How long the insulin continues to lower blood glucose
Important for exams: Hypoglycemia risk is highest at peak time.
Ultra Rapid-Acting Insulin
Ultra rapid insulin is a newer category. These insulins are modified to work even faster by adding absorption enhancers.
Medications:
- Fiasp (faster-acting aspart with niacinamide/Vitamin B3)
- Lyumjev (ultra rapid lispro formulation)
Onset, Peak, Duration:
- Onset: ~5 minutes
- Peak: ~1 hour
- Duration: ~3 hours
NCLEX Mnemonic Trick:
“Sugar running free, ultra rapid works in 5-1-3.”
- 5 = onset
- 1 = peak
- 3 = duration
Ultra rapid = FASTEST onset of all insulin types.
Rapid-Acting Insulin
These are very common insulins used for mealtime coverage.
Medications:
- Humalog (lispro)
- Novolog (aspart)
- Apidra (glulisine)
Onset, Peak, Duration:
- Onset: ~15 minutes
- Peak: ~1 hour
- Duration: ~3 hours
Key Difference from Ultra Rapid:
The onset is slightly slower (15 minutes vs. 5 minutes).
Peak and duration are similar.
NCLEX Mnemonic Trick:
“15 minutes feels like 1 hour during 3 rapid responses.”
- 15 = onset
- 1 = peak
- 3 = duration
Short-Acting Insulin
Medication:
- Humulin R (Regular insulin)
- Novolin R
Onset, Peak, Duration:
- Onset: ~30 minutes
- Peak: ~2 hours
- Duration: ~8 hours
NCLEX Mnemonic Trick:
“Short staff nurses went from 30 patients to (2) 8.”
- 30 = onset
- 2 = peak
- 8 = duration
Insulin Types Nursing Review
Critical Exam Points About Regular Insulin
- It is the ONLY insulin given IV
Regular insulin is approved for intravenous administration (important in DKA).
- Mixing Insulin: Regular + NPH
If mixing short-acting (Regular) with intermediate (NPH):
- Draw up Regular first
- Then draw up NPH
How to remember:
- “RN” = Regular then NPH
- “Clear to cloudy”
- Regular = clear
- NPH = cloudy
Always draw up clear before cloudy.
Intermediate-Acting Insulin
Medication:
- Humulin N
- Novolin N
- NPH (generic)
Onset, Peak, Duration:
- Onset: ~2 hours
- Peak: ~8 hours
- Duration: ~16 hours
NCLEX Mnemonic Trick:
“Nurses play hero to (2) eight 16 year olds.”
- 2 = onset
- 8 = peak
- 16 = duration
Long-Acting Insulin
Long-acting insulin provides basal coverage.
Medications:
- Lantus (glargine)
- Levemir (detemir) discontinued
- Tresiba (degludec)
Onset, Peak, Duration:
- Onset: ~2 hours
- Peak: None (or minimal)
- Duration: ~24 hours
What Makes Long-Acting Unique?
- Longest duration
- No pronounced peak
- Lower hypoglycemia risk compared to peak insulins
NCLEX Mnemonic Trick:
“The 2 long nursing shifts never peaked but lasted 24 hours.”
- 2 = onset
- No peak
- 24 = duration
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