A compounding pharmacy is a licensed pharmacy that prepares customized medications by mixing or altering ingredients to meet a specific need — such as a different dose, form, or formulation than what's commercially manufactured. Compounding pharmacies have played a significant role in the GLP-1 space by producing compounded semaglutide and similar products, particularly during brand-name drug shortages, though these products are not FDA-approved in the same way as manufacturer-produced medications.