Does tirzepatide (glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist) reduce immunity?

Tirzepatide Does Not Reduce Immunity

Based on the available evidence, there is no indication that tirzepatide reduces immunity or compromises immune function.

Mechanism of Action and Effects

• Tirzepatide is a dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptor agonist, representing the first drug in a class known as "twincretins" 1
• The primary mechanisms of action include:
  • Stimulating insulin secretion from pancreatic β-cells in response to elevated glucose levels 2
  • Inhibiting glucagon secretion in hyperglycemic states 2
  • Delaying gastric emptying through vagal nerve-mediated effects 2
  • Reducing appetite and food intake via receptors in the hypothalamus and brainstem 2

Documented Effects and Safety Profile

• Tirzepatide has demonstrated significant efficacy in:

  • Reducing HbA1c levels (1.7-2.4% reduction from baseline) 1
  • Promoting substantial weight loss (15% at 72 weeks, up to 20.9% at higher doses) 2, 3
  • Potentially improving cardiovascular outcomes 3

• The most common adverse effects of tirzepatide are gastrointestinal in nature, similar to other GLP-1 receptor agonists 2:

  • Nausea and vomiting
  • Dyspepsia
  • Diarrhea
  • Gastrointestinal reflux
  • Constipation 2

• In clinical trials, tirzepatide demonstrated a favorable safety profile:

  • It does not significantly increase the risk of severe hypoglycemia compared to usual care (RR, 1.32 [CI, 0.78 to 2.22]) 2
  • It may reduce serious adverse events compared to insulin (RR, 0.80 [CI, 0.67 to 0.96]) 2

Immune System Considerations

• None of the available guidelines or research evidence mentions immune suppression or compromised immunity as an adverse effect of tirzepatide 2, 3
• The comprehensive reviews of tirzepatide's clinical pharmacology, adverse effects, and safety profile do not list immunosuppression or increased infection risk 2
• The anti-inflammatory effects of GLP-1 receptor agonists mentioned in some studies are generally considered cardioprotective rather than immunosuppressive 2

Clinical Implications

• When prescribing tirzepatide, clinicians should be aware of:

  • The need for dose titration to minimize gastrointestinal side effects 2
  • Potential cardiac effects, though these are generally beneficial rather than harmful 2
  • Contraindications in specific populations, such as those with gastroparesis 2

• There is no need for special monitoring of immune function or increased vigilance for infections in patients taking tirzepatide based on current evidence 2

Conclusion

The available evidence from clinical trials and guidelines does not suggest that tirzepatide reduces immunity or increases susceptibility to infections. Its safety profile is well-established, with adverse effects primarily limited to gastrointestinal symptoms similar to those observed with other GLP-1 receptor agonists 2.