GLP-1 Drugs

What are GLP-1 Drugs?

• GLP-1 (Glucagon-Like Peptide-1) is a naturally occurring gut hormone (incretin) released after food intake.
• It plays a crucial role in regulating blood sugar, lipid metabolism, and appetite.
• GLP-1 receptor agonists are synthetic drugs that mimic this hormone, binding to its receptors to activate similar physiological responses.
• These drugs are mainly injectables, though oral versions are under development.
• Examples: Two leading GLP-1 drugs are:
  • Semaglutide (by Novo Nordisk)
  • Tirzepatide (by Eli Lilly)
• Both have been introduced in India and are transforming obesity and diabetes treatment.

How Do GLP-1 Drugs Work?

• These drugs act by:
  • Increasing insulin secretion when glucose is high.
  • Inhibiting glucagon release, reducing liver glucose output.
  • Slowing gastric emptying, preventing sudden spikes in blood sugar.
  • Suppressing appetite, making the person feel full sooner.
• Tirzepatide additionally mimics GIP (Glucose-dependent Insulinotropic Polypeptide) for dual action.

Genesis and Development

• Though incretins were first discussed in 1906, their potential was recognised only after insulin's discovery in 1921.
• The hormone GLP-1 was isolated in 1986.
• Initial trials in the 1990s showed promising results, but the hormone was unstable.
• Novo Nordisk developed liraglutide (daily injectable) and later semaglutide (weekly), which had greater weight loss efficacy and fewer side effects when doses were carefully adjusted.