In December 2025, FDA issued a Warning Letter to Darmerica, an Active Pharmaceutical Ingredient (API) importer/manufacturer citing cGMP violations, distribution of retatrutide to 503A compounding pharmacies, and failure to list all drugs distributed into interstate commerce in violation of section 510(j) of the FD&C Act. The Warning Letter follows an FDA inspection and the company’s subsequent FDA Form 483 response. Because the Warning Letter is heavily redacted, the identity of the foreign API Manufacturer is not discernable (Darmerica is listed as the U.S. Agent).
Retatrutide cannot be compounded because it is currently an investigational drug. 503A compounders may only compound a drug that is FDA approved or is a component of an FDA approved drug, or has a USP/NF monograph (albeit not a dietary supplement monograph), or appears on the FDA 503A Bulks List or interim list.
Some alleged cGMP violations were directed at lack of Quality Unit oversight for API materials, repackaging, relabeling and related controls such as adequate stability data, failure to adequately investigate quality-related complaints and inadequate recall procedures. An important allegation was failure to ensure adequate pre-release testing of APIs. FDA alleges API was released prior to review of the Certificates of Analysis (COA) and authorization for release by the company’s third party testing laboratory. This is a violation as API samples to third party laboratories for testing must be received by the U.S. facility rather than sent directly from the foreign API manufacturer to ensure the sample is representative of the API in question and to account for transport conditions. Original labels from foreign API manufacturers must never be destroyed.
Robust Quality Unit oversight and supplier qualification procedures must be in place.
Robust Quality Unit oversight and supplier qualification procedures must be in place. FDA is now increasing foreign API manufacturer oversight via inspections, use of remote document requests and Import Alerts, placing foreign manufacturers on the so-called ‘Red List’ for failure to provide or provide access to documents or records under section 704(a) of the FD&C Act.
In the Warning Letter, FDA identified a number of GLPs and peptides ineligible for 503A compounding which the company distributed such as thymogen, elamipretide acetate (SS-31), FGL acetate (AKA GLP-1-FGL peptide acetate), cagrilinitide acetate and buserelin acetate.
Other notable issues included mislabeling by importation of drugs as ‘custom peptides’ rather than by peptide name, receipt of drugs from establishments not registered with FDA and mismatch between API and structured Product Labeling.
If you need an attorney who has the specific expertise in the compounding space with regard to supply chain and FDA (or Board of Pharmacy rules), contact us today.




