Researchers aren’t certain that diabetes and high blood sugar levels directly cause hair loss, says Dr. Venkatesh. But type 1 and type 2 diabetes are both associated with a variety of known hair loss risk factors.
Poor Blood Circulation
Hair follicles need oxygen-rich blood flow to grow. Chronic high blood sugar levels, known as hyperglycemia, can damage blood vessels and compromise the oxygen and nutrient supply to hair follicles. This, in turn, may disrupt hair growth and lead to shedding.
“If there is less blood flow to the scalp, this, in theory, could decrease the ability for hair to grow,” says Venkatesh.
The Diabetes-Autoimmune Relationship
People with type 1 diabetes often have other autoimmune conditions, and both alopecia areata and Hashimoto’s thyroiditis are associated with hair loss.
There may be a scientific connection to prediabetes and type 2 diabetes and alopecia areata too. In one study of people with alopecia areata, people were 62 percent more likely to have prediabetes compared with a control group. Researchers suspect there may be common inflammatory responses in the body between the two conditions, though more research is needed.
Venkatesh says that centrifugal cicatricial alopecia (CCCA), a type of rare, scarring hair loss, also has a known association with diabetes.
Diabetes Medications
GLP-1 agonists are one class of medications that help manage blood sugar in people with type 2 diabetes. Semaglutide, also known by its brand name Ozempic, is widely prescribed and has generated many reports of hair loss.
“I have seen hair loss in patients who are on these medications,” says Hannah B. Kopelman, MD, a hair restoration surgeon and dermatologist at Kopelman Hair Restoration in New York City.
GLP-1 hair loss may be caused by the rapid weight loss these medications can spark — not the drugs. People who achieve dramatic weight loss using other means also sometimes experience temporary hair loss.Dr. Kopelman says that hair grows back on its own, and people who take these meds may have a better head of hair in the long run.
“When the body is in a healthier state with more controlled insulin, I’ve seen people’s hair become thicker and grow better,” says Kopelman.
While GLP-1 hair loss may not be a significant concern, there are other drugs that are known to cause hair loss, some of which are often prescribed to people with diabetes. Many people with diabetes take medications for hypertension, high cholesterol, gout, thyroid disease, and depression which carry a risk of temporary or permanent hair loss.
Thyroid Issues
People with diabetes have a higher risk of developing both hyperthyroidism and hypothyroidism. These thyroid conditions are strongly associated with hair loss. According to a one study, 33 percent of people with hypothyroidism and 50 percent of people with hyperthyroidism may experience excessive hair shedding.
Iron Deficiency
There is a link between higher A1C levels and iron deficiency,and iron deficiency can directly contribute to hair loss. The mineral plays a role in producing hemoglobin, which is the protein in red blood cells that delivers oxygen to the cells throughout your body.
Polycystic Ovarian Syndrome (PCOS)
PCOS, a hormonal disorder that impacts women of reproductive age, shares a common risk factor with type 2 diabetes — insulin resistance — and the two conditions often coexist. PCOS can cause the body to produce an excess of testosterone, and a common side effect of that is thinning hair.
Stress
Managing a chronic condition can be a lot to handle, and stress is linked to hair loss too.
“Stress can definitely contribute to hair shedding,” says Venkatesh.
