Insulin

A life-saving peptide hormone essential for glucose regulation.

What is Insulin?

Insulin is a peptide hormone produced by the β-cells of the pancreas. It regulates blood glucose by promoting glucose uptake into cells.

Insulin therapy is essential in type 1 diabetes and advanced type 2 diabetes.

History & Background

Insulin was discovered in 1921 by Banting and Best, transforming diabetes from a fatal disease into a manageable condition.

Chemical Structure & Properties

• Type: Peptide hormone
• Chains: A chain (21 amino acids), B chain (30 amino acids)
• Molecular weight: ~5808 Da
• Bonds: Disulfide bridges

Mechanism of Action

Insulin lowers blood glucose by:

• Increasing glucose uptake in muscle and fat
• Stimulating glycogen synthesis
• Inhibiting gluconeogenesis
• Reducing lipolysis and proteolysis

Types of Insulin

• Rapid-acting (Lispro, Aspart)
• Short-acting (Regular insulin)
• Intermediate-acting (NPH)
• Long-acting (Glargine, Detemir)
• Ultra-long acting (Degludec)

Pharmacokinetics

• Route: Subcutaneous injection
• Onset: Varies by type
• Duration: 3–42 hours (type-dependent)
• Metabolism: Liver and kidneys

Medical Uses

• Type 1 diabetes mellitus
• Type 2 diabetes mellitus (advanced)
• Diabetic ketoacidosis
• Gestational diabetes

Dosage Principles

Dosage is individualized based on blood glucose monitoring, diet, activity, and insulin type.

⚠️ Incorrect dosing can cause severe hypoglycemia.

Side Effects

• Hypoglycemia
• Weight gain
• Lipodystrophy at injection site
• Allergic reactions (rare)

Warnings & Precautions

• Monitor blood glucose regularly
• Rotate injection sites
• Recognize hypoglycemia symptoms

Drug Interactions

• Beta-blockers (mask hypoglycemia)
• Alcohol
• Corticosteroids

Frequently Asked Questions

Is insulin oral? – No.

Is insulin addictive? – No.

Can insulin cause low sugar? – Yes.

Is insulin life-long? – Often in type 1 diabetes.

⚠️ Educational content only. Not a substitute for professional medical advice.