Neurologists are raising concerns that popular GLP-1 agonist medications, widely used for diabetes and obesity, may accelerate the progression of amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases. The rapid weight loss these drugs induce can be detrimental to individuals with conditions where maintaining body mass is crucial for preserving nerve and muscle function.
Dr. Jinsy Andrews, a neurologist and director of NYU Langone’s ALS Center, explained that while GLP-1s are effective for general population health concerns like obesity and diabetes, the biological needs of ALS patients differ significantly. For individuals with ALS, losing weight can hasten physical decline because the disease's characteristics make being in a caloric deficit particularly harmful.
Standard clinical care for ALS often recommends patients maintain or even gain weight to help preserve remaining nerve and muscle function. Andrews noted that in conditions involving hypermetabolism, weight loss can worsen the disease and lead to faster progression. "So, in the setting of a person with ALS — whether they have diabetes or not — using GLP-1s may actually worsen the disease and make for a rapid progression," she stated.
This concern is underscored by a 2025 case report published in the journal Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. The report detailed the case of a 52-year-old ALS patient who was prescribed semaglutide for type 2 diabetes. Prior to the medication, her physical functions were declining at a predictable rate. However, after starting semaglutide, she experienced a rapid 25-pound weight loss within three months, accompanied by a dramatic acceleration in her disease's progression and worsening symptoms.
Once the medication was discontinued on medical advice, the patient's rapid physical decline stabilized. Andrews pointed to this case report, along with retrospective data from ALS patients with diabetes, as growing evidence suggesting that clinicians must exercise caution when prescribing GLP-1 receptor agonists to patients with underlying neurodegenerative diseases.
While GLP-1 medications have demonstrated significant benefits for many, including reducing inflammation related to obesity and diabetes, and have been linked to protective effects against cardiovascular disease, stroke, liver disease, and addiction, experts emphasize that maintaining body weight and muscle mass remains a critical consideration for individuals managing neurodegenerative conditions.