Insulin — NPH — Half-Life, Dosing & Protocol Guide

Also known as: Humulin N, Novolin N, Isophane insulin, NPH insulin

Pharmacokinetics & Mechanism

NPH insulin (Neutral Protamine Hagedorn — Humulin N/Novolin N) is human insulin co-crystallised with protamine and zinc. The crystalline depot dissolves slowly after subcutaneous injection: onset 1–3 hours, peak effect 4–12 hours, duration up to 24 hours (per FDA NDA 018781). The pronounced 4–12h peak creates a nocturnal hypoglycaemia risk when dosed at bedtime. Must never be administered intravenously. Cannot be mixed with insulin analogs (lispro, aspart) due to protamine interactions affecting absorption profiles.

Track Insulin — NPH in Halflife

The Halflife app models your Insulin — NPH concentration curve in real time — see exactly when your dose peaks, when it troughs, and how it overlaps with other compounds in your stack. All stored on-device, no account required.