Dermatological adverse reactions and therapeutic potential of semaglutide, liraglutide and tirzepatide: Analysis of UK pharmacovigilance data and literature review

Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) are recognised as transformative therapies with complex dermatological profiles, extending beyond their established metabolic benefits. GLP-1 receptors (GLP-1Rs) are present in various tissues, including keratinocytes and immune cells, triggering intracellular signalling. While widely distributed, GLP-1R expression in circulating immune cell populations may be undetectable, suggesting indirect effects on their gene expression. Clinical evidence indicates significant improvements in psoriasis severity, with Psoriasis Area and Severity Index (PASI) reductions ranging from approximately 19% to over 98% in reported cases. These benefits are attributed to GLP-1RAs' anti-inflammatory and immunomodulatory properties, including pro-inflammatory cytokine reduction and immune cell modulation. They also show promising effects for hidradenitis suppurativa (HS), reducing lesion severity and improving quality of life. However, GLP-1RAs are associated with various adverse dermatological effects, including alopecia, common injection site reactions, rare immune-mediated conditions such as bullous pemphigoid, and "Ozempic face" (facial fat loss). UK Medicines and Healthcare products Regulatory Agency (MHRA) data through May 2025 show 1,369 dermatological reports, with alopecia among the most frequent specific reactions. Tirzepatide (a dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 agonist with mechanistic advantages) had the highest alopecia reports (140), followed by semaglutide (91) and liraglutide (18). Recent US pharmacovigilance surveillance shows a 186% increase in dermatological event reporting from 2022-2023. Dermatologists must balance therapeutic opportunities in inflammatory conditions against these emerging safety concerns, employing proactive monitoring and comprehensive patient counselling as GLP-1RAs expand beyond diabetes into weight management.