Do Glucagon-like peptide-1 (GLP-1) medications, such as liraglutide (Victoza) and semaglutide (Ozempic), cause hair loss?

Do GLP-1 Medications Cause Hair Loss?

Based on current clinical guidelines and available evidence, GLP-1 receptor agonists (GLP-1 RAs) are not associated with hair loss as a documented side effect. The comprehensive safety profiles outlined in major guidelines do not list alopecia or hair loss among the known adverse effects of these medications.

Known Side Effects of GLP-1 RAs

The most commonly reported side effects of GLP-1 receptor agonists include:

• Gastrointestinal effects: Nausea, vomiting, diarrhea, and dyspepsia (occurring in 15-20% of patients) 1
• Gallbladder disorders: Including acute cholecystitis 2
• Cardiovascular effects: Potential elevations in heart rate 2
• Retinopathy complications: Particularly with rapid glucose reduction (noted with semaglutide) 2
• Injection site reactions: With injectable formulations

Safety Profile from Guidelines

According to the 2018 American College of Cardiology expert consensus 2, the most frequently reported side effects are gastrointestinal symptoms, which are usually transient for longer-acting GLP-1 RAs and can be mitigated by gradual dose escalation and patient education about reducing meal size.

The American Diabetes Association and European Association for the Study of Diabetes consensus report 2 similarly does not mention hair loss among the known adverse effects of GLP-1 RAs.

Hair Loss and Medications

While many medications can cause hair loss through different mechanisms 3, including:

1. Anagen effluvium: Abrupt cessation of mitotic activity in hair matrix cells (common with antineoplastic agents)
2. Telogen effluvium: Precipitating hair follicles into premature rest (seen with anticoagulants, retinoids, interferons, and antihyperlipidemic drugs)

GLP-1 RAs are not included in these categories of medications associated with hair loss.

Clinical Trial Data

Large clinical trials evaluating GLP-1 RAs such as:

• LEADER trial (liraglutide) 2
• SUSTAIN-6 trial (semaglutide) 2
• PIONEER 4 trial (oral semaglutide vs. subcutaneous liraglutide) 4

Have not reported hair loss as a significant adverse event. These trials comprehensively documented side effects, and the absence of hair loss in their reports suggests this is not a common concern with these medications.

Weight Loss and Hair Loss

It's worth noting that significant weight loss from any cause (including that induced by GLP-1 RAs) can sometimes trigger telogen effluvium, a temporary form of hair loss. GLP-1 RAs can produce substantial weight loss:

• Liraglutide: 2-4% of total body weight 2
• Semaglutide: Up to 10% of total body weight 2, with some studies showing even greater weight loss (13.8% at the 0.4 mg dose) 5

If a patient experiences hair loss while taking a GLP-1 RA, it may be related to the rapid weight loss rather than a direct effect of the medication itself.

Practical Considerations

If a patient reports hair loss while taking a GLP-1 RA:

1. Evaluate the timing and pattern of hair loss
2. Consider whether significant weight loss has occurred
3. Rule out other common causes of hair loss (nutritional deficiencies, thyroid disorders, other medications)
4. If concerned about a potential relationship, consider slowing the rate of weight loss by adjusting the GLP-1 RA dose escalation schedule

Conclusion

Current clinical guidelines and research do not identify hair loss as a known side effect of GLP-1 receptor agonists. If hair loss occurs in patients taking these medications, it is more likely related to rapid weight loss or other factors rather than a direct medication effect.