Chart — Endocrine

Insulin Comparison Chart

All insulin formulations — rapid, short, intermediate, long-acting, and concentrated — with onset, peak, duration, appearance, and key nursing notes. Organized by class for fast reference.

Source: ADA Standards of Medical Care in Diabetes; insulin manufacturer prescribing information; clinical pharmacology references.

Educational use only. Insulin selection, dosing, and timing are provider decisions; always verify against current orders, pharmacy guidance, and facility policy before administration. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.

Insulin is a HIGH-ALERT medication. Double-check dose with a second nurse per policy. Verify the correct formulation and concentration before administration. Never substitute brands without a provider order.

Clear vs. Cloudy Rule

All insulins are clear EXCEPT NPH which is cloudy. When mixing NPH with regular insulin: draw up clear (regular) first, then cloudy (NPH).

Rapid-Acting

Insulin	Onset	Peak	Duration	Look	Key Nursing Notes
Lispro (Humalog)	10–15 min	1–2 hr	3–5 hr	Clear	Give immediately before meals. Hold if NPO. Most common mealtime insulin in hospitals.
Aspart (NovoLog)	10–20 min	1–3 hr	3–5 hr	Clear	Give 5–10 min before meals. Used in insulin pumps (CSII). Preferred in some protocols.
Glulisine (Apidra)	10–15 min	1–1.5 hr	3–5 hr	Clear	Give within 15 min before meals or within 20 min after starting a meal.

Short-Acting

Insulin	Onset	Peak	Duration	Look	Key Nursing Notes
Regular (Humulin R / Novolin R)	30–60 min	2–4 hr	6–8 hr	Clear	ONLY insulin for IV use (drip or push). Give SQ 30 min before meals. Used for DKA insulin drips.

Intermediate-Acting

Insulin	Onset	Peak	Duration	Look	Key Nursing Notes
NPH (Humulin N / Novolin N)	1–2 hr	4–12 hr	18–24 hr	CLOUDY	Roll gently to mix — do NOT shake. When mixing with regular: draw clear (regular) first. Peak at 4–12 hr = highest hypoglycemia risk window.

Long-Acting (Basal)

Insulin	Onset	Peak	Duration	Look	Key Nursing Notes
Glargine (Lantus / Basaglar / Toujeo)	1–2 hr	Peakless	20–24 hr	Clear	Once daily. Never mix. Clear despite being basal. Give at consistent time daily. Toujeo = 3× concentration (300 units/mL).
Detemir (Levemir)	1–2 hr	Flat (mild 6–8 hr)	18–22 hr	Clear	Once or twice daily. Never mix. Dose-dependent duration. Weight-based dosing common.
Degludec (Tresiba)	~1 hr	Peakless	>42 hr	Clear	Ultra-long basal. Flexible dosing window (±8 hours). Never mix. Steady state reached in 3–4 days.

Concentrated

Insulin	Onset	Peak	Duration	Look	Key Nursing Notes
Regular U-500 (Humulin R U-500)	30 min	4–8 hr	Up to 24 hr	Clear	HIGH-ALERT. 500 units/mL (5× standard). ONLY use U-500 syringe or pen. NEVER use U-100 syringe — 5× overdose risk.

Critical Timing Rules

Type	When to Give	If NPO / Cannot Eat
Rapid-acting	Immediately before meals (or within 15 min after starting)	HOLD — notify provider. Hypoglycemia risk without oral intake.
Regular (SQ)	30 minutes before meals	HOLD SQ dose. IV infusion continues per protocol.
NPH	Per schedule (usually AM and/or bedtime)	Notify provider; may adjust dose during illness or NPO
Long-acting (basal)	Same time each day	Generally continue basal coverage — notify provider to confirm

Related Resources

Insulin Types ReferenceDetailed formulation notes, clinical rules, and timing guidance

Open →

Diabetic KetoacidosisInsulin drip protocols and DKA management

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Glycemic Targets ReferenceHospital glucose goals and hypoglycemia thresholds

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Standards & sources

Fact-checked Jun 20, 2026

This page is written to align with ADA Standards of Medical Care in Diabetes; Insulin Manufacturer Prescribing Information. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →