Drug-induced hair loss is one of the more common causes of telogen effluvium presentations in dermatology, but it's frequently missed because patients don't think to mention recent medication changes during hair consultations. A standardised review of medications added or changed in the 3–6 months preceding hair loss onset is one of the highest-yield diagnostic steps in evaluating unexplained shedding.

Common culprits include: anticoagulants (heparin, warfarin), beta-blockers (propranolol, metoprolol), ACE inhibitors, lithium, anticonvulsants (valproic acid, carbamazepine), antithyroid drugs, immunosuppressants, retinoids (isotretinoin, etretinate), chemotherapy agents (broad category), and increasingly recognised, GLP-1 agonists like semaglutide. Hormonal contraceptives can trigger telogen effluvium both at initiation and discontinuation.

Practical evaluation approach: review all medications including OTC products and supplements added in the 3–6 months before hair shedding began. Check for documented hair-loss associations in prescribing information or drug references. Consider whether the drug can be discontinued, dose-reduced, or substituted with a different agent in the same class. Always discuss with the prescribing physician before making changes. Resolution of drug-induced telogen effluvium typically occurs 3–6 months after the offending drug is stopped, with full hair density recovery in most cases.