Millions of people now use medicines such as semaglutide and tirzepatide because they can lower blood sugar and support significant weight loss. A new investigation published in The BMJ has found that these medicines may slightly increase the risk of hair loss compared with other diabetes drugs. The study found that people taking GLP-1 receptor agonists experienced hair loss more often than people taking the comparison medicines. They did not have enough clinical detail to measure exactly how serious the hair loss was or whether it completely reversed after treatment ended. Anyone concerned about hair loss should discuss the issue with a healthcare professional before making changes to their medication.