Popular Weight Loss and Diabetes Drugs Linked to Higher Risk of Hair Loss, Study Finds

PHILADELPHIA — Commonly prescribed GLP-1 receptor agonist medications used for weight loss and type 2 diabetes—including Mounjaro, Ozempic, and Wegovy—are associated with a significantly increased risk of hair loss, according to a major study published in the British Medical Journal.

Analyzing electronic health records from roughly 50,000 patients within the University of Pennsylvania Health System, researchers found that users taking GLP-1 drugs were substantially more likely to develop alopecia compared to those taking other standard diabetes medications.

What the Study Revealed

To determine the strength of the connection, researchers compared patients with type 2 diabetes on GLP-1s against two control groups: those taking SGLT-2 inhibitors and those taking DPP-4 inhibitors.

After adjusting for influencing factors such as age and weight, the findings showed:

• 37% Higher Risk: Patients using GLP-1 drugs had a 37% increased risk of hair loss compared to those taking SGLT-2 inhibitors.

• 68% Higher Risk: GLP-1 users faced a 68% higher risk of hair loss compared to those on DPP-4 inhibitors.

• Reversible Hair Loss: Further analysis confirmed the hair loss is non-scarring alopecia, meaning the hair follicles remain intact, leaving the potential for full regrowth once conditions stabilize.

Regulators Track Surge in Reports

Regulatory bodies in both the US and the UK have been monitoring the potential link following an influx of voluntary patient reports.

In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) has received a growing number of reports involving tirzepatide (sold as Mounjaro) and semaglutide (sold as Wegovy and Ozempic):

• Tirzepatide: 399 reports of hair loss received so far in 2026, following 541 reports filed last year.

• Semaglutide: 148 reports submitted so far in 2026, following 164 reports last year.

The US Food and Drug Administration (FDA) has also indicated that it is evaluating hair loss as a potential safety signal following similar reports in its Adverse Event Reporting System.

Why Is the Hair Loss Happening?

While further research is needed, experts point to rapid weight loss and reduced calorie intake as the primary drivers behind the condition.

• Nutritional and Physical Stress: Caloric restriction can cause physiological stress and key micronutrient deficiencies—such as iron, zinc, and biotin—which disturb the natural hair growth cycle.

• Hormonal Changes: GLP-1 medications can influence thyroid function and delay gastric emptying. This delay may affect how the body absorbs other essential oral treatments, including thyroid or sex hormone therapies, triggering hair loss through endocrine mechanisms.

Psychosocial Impact

Although non-scarring hair loss does not pose physical danger, the study's authors emphasized that its psychological toll should not be overlooked.

"Although hair loss does not typically result in physical harm, it may have significant psychosocial consequences, affecting self-esteem, quality of life, and adherence to treatment," the research team noted, emphasizing that clinicians should actively discuss this potential side effect with patients undergoing GLP-1 therapy.