{"abstract":"The Food and Drug Administration (FDA or we) is announcing the availability of a guidance entitled \"Protein Efficiency Ratio (PER) Rat Bioassay Studies to Demonstrate That a New Infant Formula Supports the Quality Factor of Sufficient Biological Quality of Protein.\" The guidance provides information for manufacturers and contract laboratories that perform PER studies to assist in designing, conducting, evaluating, and reporting PER studies. The guidance explains \"appropriate modifications\" of AOAC Official Method 960.48 (the AOAC Method) with the aim of supporting industry in successfully conducting PER studies that demonstrate that a new infant formula meets the quality factor of sufficient biological quality of protein when fed as the sole source of nutrition. The guidance finalizes the approach presented in the draft guidance issued in 2023.","action":"Notice of availability.","agencies":[{"raw_name":"DEPARTMENT OF HEALTH AND HUMAN SERVICES","name":"Health and Human Services Department","id":221,"url":"https://www.federalregister.gov/agencies/health-and-human-services-department","json_url":"https://www.federalregister.gov/api/v1/agencies/221","parent_id":null,"slug":"health-and-human-services-department"},{"raw_name":"Food and Drug Administration","name":"Food and Drug Administration","id":199,"url":"https://www.federalregister.gov/agencies/food-and-drug-administration","json_url":"https://www.federalregister.gov/api/v1/agencies/199","parent_id":221,"slug":"food-and-drug-administration"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2026/05/22/2026-10284.html","cfr_references":[],"citation":"91 FR 30318","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"The announcement of the guidance is published in the Federal Register on May 22, 2026.","disposition_notes":null,"docket_ids":["Docket No. FDA-2022-D-2424"],"dockets":[{"supporting_documents":[{"title":"Appendix 6 Ref. 1 - Nutrient Requirements of Laboratory Animals","document_id":"FDA-2022-D-2424-0048"},{"title":"Appendix 5 Ref. 5 - Nutrient Requirements of Lab Animals - 3rd Revised Edition","document_id":"FDA-2022-D-2424-0046"},{"title":"Appendix 5 Ref. 3 - AIN Diets_1980_2","document_id":"FDA-2022-D-2424-0044"},{"title":"Appendix 5 Ref. 2 - AIN Diets_1977_1","document_id":"FDA-2022-D-2424-0043"},{"title":"Appendix 5 Ref. 1 - AOAC Official Method 960.48","document_id":"FDA-2022-D-2424-0042"},{"title":"Final Guidance Ref. 25 - Lactose Load Diet Effect in Rats","document_id":"FDA-2022-D-2424-0039"},{"title":"Final Guidance Ref. 24 - GMA Test Protocol for Protein Quality Assays","document_id":"FDA-2022-D-2424-0038"},{"title":"Final Guidance Ref. 22 - Purified Diets for Lab Rodents","document_id":"FDA-2022-D-2424-0036"},{"title":"Final Guidance Ref. 21 - Relationship btn Amino Acid Scores and Protein Quality","document_id":"FDA-2022-D-2424-0035"},{"title":"Final Guidance Ref. 20 - Sulfur Amino Acid Requirements of the Growing Rat","document_id":"FDA-2022-D-2424-0034"}],"agency_name":"FDA","documents":[{"comment_count":0,"comment_start_date":"2026-05-22","updated_at":"2026-05-22T11:57:02.763-04:00","comment_url":"https://www.regulations.gov/commenton/FDA-2022-D-2424-0012","allow_late_comments":false,"id":"FDA-2022-D-2424-0012","comment_end_date":null,"regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":37,"id":"FDA-2022-D-2424","title":"Protein Efficiency Ratio (PER) Rat Bioassay Studies to Demonstrate that a New Infant Formula Supports the Quality Factor of Sufficient Biological Quality of Protein; Draft Guidance for Industry; Availability; Agency Information Collection Activities; Proposed Collection; Comment Request"}],"document_number":"2026-10284","effective_on":null,"end_page":30319,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/05/22/2026-10284.xml","html_url":"https://www.federalregister.gov/documents/2026/05/22/2026-10284/protein-efficiency-ratio-rat-bioassay-studies-to-demonstrate-that-a-new-infant-formula-supports-the","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-10284?publication_date=2026-05-22","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-05-22/2026-10284/mods.xml","not_received_for_publication":null,"page_length":2,"page_views":{"count":234,"last_updated":"2026-07-28 14:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-05-22/pdf/2026-10284.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-10284.pdf?1779367512","publication_date":"2026-05-22","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/05/22/2026-10284.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"Appendix 6 Ref. 1 - Nutrient Requirements of Laboratory Animals","document_id":"FDA-2022-D-2424-0048"},{"title":"Appendix 5 Ref. 5 - Nutrient Requirements of Lab Animals - 3rd Revised Edition","document_id":"FDA-2022-D-2424-0046"},{"title":"Appendix 5 Ref. 3 - AIN Diets_1980_2","document_id":"FDA-2022-D-2424-0044"},{"title":"Appendix 5 Ref. 2 - AIN Diets_1977_1","document_id":"FDA-2022-D-2424-0043"},{"title":"Appendix 5 Ref. 1 - AOAC Official Method 960.48","document_id":"FDA-2022-D-2424-0042"},{"title":"Final Guidance Ref. 25 - Lactose Load Diet Effect in Rats","document_id":"FDA-2022-D-2424-0039"},{"title":"Final Guidance Ref. 24 - GMA Test Protocol for Protein Quality Assays","document_id":"FDA-2022-D-2424-0038"},{"title":"Final Guidance Ref. 22 - Purified Diets for Lab Rodents","document_id":"FDA-2022-D-2424-0036"},{"title":"Final Guidance Ref. 21 - Relationship btn Amino Acid Scores and Protein Quality","document_id":"FDA-2022-D-2424-0035"},{"title":"Final Guidance Ref. 20 - Sulfur Amino Acid Requirements of the Growing Rat","document_id":"FDA-2022-D-2424-0034"}],"comments_count":0,"agency_id":"FDA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FDA-2022-D-2424","supporting_documents_count":37,"docket_id":"FDA-2022-D-2424","document_id":"FDA-2022-D-2424-0012","regulation_id_number":null,"title":"Protein Efficiency Ratio (PER) Rat Bioassay Studies to Demonstrate that a New Infant Formula Supports the Quality Factor of Sufficient Biological Quality of Protein; Draft Guidance for Industry; Availability; Agency Information Collection Activities; Proposed Collection; Comment Request","checked_regulationsdotgov_at":"2026-05-22T18:55:04Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":30318,"subtype":null,"title":"Protein Efficiency Ratio Rat Bioassay Studies To Demonstrate That a New Infant Formula Supports the Quality Factor of Sufficient Biological Quality of Protein; Guidance for Industry; Availability","toc_doc":"Protein Efficiency Ratio Rat Bioassay Studies to Demonstrate That a New Infant Formula Supports the Quality Factor of Sufficient Biological Quality of Protein","toc_subject":"Guidance","topics":[],"type":"Notice","volume":91}