Compounded peptide

How is a compounded peptide different from an FDA-approved peptide drug?

Federal law allows peptide compounding by a licensed pharmacist or physician in a state-licensed pharmacy, or by a 503B outsourcing facility under a pharmacist's direct supervision [1]. A 503A compounding pharmacy is not registered with FDA as an outsourcing facility [2]. Compounded peptides are not FDA-approved, so the agency does not verify their safety, effectiveness or quality before marketing [1]. FDA also distinguishes compounded drugs from generics: a generic is FDA-approved and must prove therapeutic equivalence to a brand-name drug, while a compounded peptide is not [1]. Compounded medications are not reviewed or approved by the FDA for safety or effectiveness.

What are the risks and limits of compounded peptides?

FDA warns that poor compounding practices can cause serious quality problems, such as contamination or a drug with too much or too little active ingredient, leading to serious injury or death [1]. Some are excluded outright: FDA states that retatrutide and cagrilintide cannot be used in compounding under federal law, are not in any approved drug, and have not been found safe and effective [3]. FDA also says certain salt forms, such as semaglutide sodium, are different active ingredients with no known lawful basis for compounding [3]. Because pharmacies that are not outsourcing facilities are not required to report adverse events to FDA, the agency believes reporting is incomplete [3].