Can tirzepatide (glucagon-like peptide-1 (GLP-1) receptor agonist) cause hair loss?

Hair Loss as a Side Effect of Tirzepatide

Based on current guidelines and evidence, hair loss (alopecia) is a documented side effect of tirzepatide, occurring in approximately 6% of patients taking the medication compared to 1% on placebo.

Evidence for Hair Loss with Tirzepatide

According to the 2024 Diabetes Care guidelines, tirzepatide (a dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist) has several documented side effects 1. While gastrointestinal effects are the most common adverse reactions, alopecia (hair loss) is specifically listed among the side effects, affecting approximately 6% of patients taking tirzepatide compared to 1% in placebo groups 1.

Common Side Effects of Tirzepatide

The most frequently reported adverse effects of tirzepatide include:

• Gastrointestinal effects (primary side effects):
  • Nausea (31% vs 10% placebo)
  • Diarrhea (23% vs 7% placebo)
  • Vomiting (12% vs 2% placebo)
  • Constipation (5% vs 3% placebo)
• Other notable side effects:
  • Alopecia (hair loss) (6% vs 1% placebo)
  • Abdominal pain (5% vs 3% placebo)

Mechanism and Patterns of Hair Loss

While the exact mechanism by which tirzepatide causes hair loss is not fully elucidated in the guidelines, it may be related to:

1. Metabolic changes induced by significant weight loss
2. Nutritional factors related to decreased food intake
3. Direct effects of GLP-1/GIP receptor activation on hair follicles

Clinical Implications and Management

For patients experiencing hair loss while on tirzepatide:

• Document the onset, pattern, and severity of hair loss
• Consider the risk-benefit ratio of continuing therapy
• Monitor nutritional status, particularly protein intake
• Reassure patients that drug-induced hair loss is often reversible upon discontinuation

Dosing Considerations

Tirzepatide is typically initiated at lower doses and gradually increased:

• Starting dose: 2.5 mg/week subcutaneously
• Maintenance doses: 5 mg, 10 mg, or 15 mg once weekly

Higher doses may be associated with increased risk of all side effects, including hair loss 1.

Other Important Safety Considerations

While discussing hair loss, it's important to be aware of other significant safety concerns with tirzepatide:

• Pancreatitis (discontinue if suspected)
• Risk of acute kidney injury (use caution in renal disease)
• Gallbladder disorders
• Gastrointestinal complications (severe constipation, small bowel obstruction)
• Potential delayed absorption of oral medications
• Black box warning for thyroid C-cell tumors in rodents 1

Conclusion

Hair loss is a recognized side effect of tirzepatide therapy that occurs more frequently than with placebo. Patients should be informed about this potential side effect when starting treatment. For most patients, the benefits of tirzepatide regarding glycemic control and weight reduction will outweigh the risk of hair loss, but individual assessment is necessary.