Doctors warn that GLP-1 weight-loss drugs like Ozempic and Wegovy may accelerate neurodegenerative diseases such as ALS, with case studies and a new study linking semaglutide to severe neurological risks, while Novo Nordisk emphasizes no official adverse reaction listings.
Neurologists are raising alarms about the potential dangers of GLP-1 receptor agonists, including Ozempic and Wegovy, for patients with neurodegenerative conditions like amyotrophic lateral sclerosis (ALS). The drugs, which induce rapid weight loss, may paradoxically worsen disease progression in individuals with ALS, according to recent findings and clinical observations.
Doctors Warn of Accelerated ALS Progression
Jinsy Andrews, MD, a neurologist and director of NYU Langone’s ALS Center, explained that the weight loss mechanism of GLP-1 drugs could harm ALS patients. In certain conditions where hypermetabolism is something that negatively affects the disease […] losing weight actually makes the disease worse and move faster,
Andrews told Fox News Digital, citing a 2025 case study of a 52-year-old ALS patient who experienced accelerated decline after using semaglutide, the active ingredient in Ozempic and Wegovy.
The patient, who had been managing type 2 diabetes, lost 25 pounds in three months while on semaglutide. Her physical deterioration worsened dramatically, but stabilization occurred after discontinuing the medication, as reported in the *Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration* journal. Andrews noted that standard ALS care often prioritizes weight maintenance to preserve muscle function, making GLP-1 drugs a potential risk for patients regardless of diabetes status.
Link to Rare Brain Illness Emerges
A July 2026 study published in *Obesity* synthesized six case reports linking semaglutide to Wernicke encephalopathy, a rare but severe neurological condition.
Of the six patients, four developed persistent memory impairments consistent with Korsakoff syndrome, and one died. The study highlighted that GLP-1 drugs’ appetite-suppressing effects may increase thiamine deficiency risks, a known trigger for Wernicke encephalopathy.
Novo Nordisk Stands by Drug Safety
Novo Nordisk, the manufacturer of Ozempic and Wegovy, emphasized that ALS and other neurodegenerative diseases are not listed as adverse reactions in the prescribing information for semaglutide.
However, the company acknowledged the complexity of treating patients with multiple conditions.
Clinical Guidance Gaps and Calls for Caution
Experts stress that while GLP-1 drugs offer significant benefits for obesity and diabetes, their use in patients with ALS or other neurodegenerative diseases requires caution. Andrews noted that maintaining body weight and muscle mass is key for people with neurodegenerative diseases, a principle that may conflict with the weight-loss goals of GLP-1 therapies.
Nonetheless, they called for heightened vigilance.
As GLP-1 drugs remain widely prescribed, the medical community faces a challenge in balancing their benefits with emerging risks. Researchers urge further studies to clarify the link between semaglutide and neurodegenerative progression, while clinicians are advised to tailor treatment plans based on individual patient profiles. For now, the focus remains on monitoring and adapting care to minimize harm.
For patients with ALS or other neurological conditions, the message is clear: consult healthcare providers before starting GLP-1 therapies, and stay informed about potential risks. As the evidence evolves, so too must clinical practices to ensure patient safety.
