Wegovy and Ozempic, two GLP-1 medications that contain the active ingredient semaglutide, have helped many people lose weight and improve metabolic health. For some, the results have been life-changing. 

But some patients notice an unexpected change a few months into treatment: more hair in the brush, more shedding in the shower or thinning around the temples.

That raises the question: Is the medication causing hair loss?

In clinical trials for semaglutide, hair loss was reported in about 3% of adults taking the medication, compared with about 1% of those taking a placebo. But the medication itself may not be the direct cause.

Rapid weight loss, significant calorie restriction, illness, surgery or emotional stress can push hair follicles into a resting phase rather than a growth phase. This condition, known as telogen effluvium, often leads to noticeable shedding two to three months after the body experiences stress.

That may help explain why some people notice shedding after starting GLP-1 treatment. With GLP-1 medications, rapid weight loss is common. Appetite often drops significantly, and some people eat far less than they realize. Protein intake may fall, along with key nutrients such as iron, zinc, B vitamins and essential fatty acids. All of these play a role in healthy hair growth.

When the body does not get enough protein or nutrients, it prioritizes essential organs over hair production. Hair isn’t necessary for survival, so it is often one of the first places the body shows signs of strain.

In other words, the medication may not be toxic to hair follicles. The bigger issue may be the metabolic shift and nutritional changes that can come with rapid weight loss.

The good news is that this type of shedding is usually temporary. Once nutrient levels improve and weight loss slows, hair growth often resumes over several months.

If you notice increased shedding while taking a GLP-1 medication, talk with your doctor. It may be helpful to evaluate iron stores, ferritin levels, protein intake and overall nutrition. In some cases, slowing the rate of weight loss may also reduce stress on the hair growth cycle.

Hair shedding alone isn’t usually a reason to panic or stop therapy abruptly. However, any concerning symptoms, especially severe abdominal pain or signs of possible pancreatic complications, should be evaluated promptly.