Educational only. Not medical or legal advice. This site summarizes public U.S. government statements as of October 22, 2026. It does not sell, recommend or endorse any product, and it does not give dosing information. Talk to a licensed clinician about any medicine, and check the linked FDA pages for the latest version.
The 503A rules in brief
Under section 503A, state-licensed pharmacists and physicians may compound only with bulk substances that meet a USP/NF monograph, are components of FDA-approved drugs, or appear on FDA's 503A bulks list. [FDA]
The interim categories
- Category 1: nominated with enough information to evaluate; FDA does not intend to take action if the guidance conditions are met. [FDA]
- Category 2: FDA identified significant safety risks; FDA would consider enforcement action under its general policies. [FDA]
- Category 3: nominated with insufficient information; not eligible for the category 1 policy. [FDA]
FDA says it does not intend to place substances nominated on or after Jan 7, 2025 into these categories. [FDA]
Peptides FDA lists in category 2
| Substance | 503A / 503B | Added |
|---|---|---|
| GHRP-2 (injectable and nasal) | 503B | Sep 29, 2023 |
| GHRP-6 | 503B | Sep 29, 2023 |
| Ibutamoren mesylate | 503A and 503B | 503A Sep 29, 2023; 503B Dec 29, 2022 |
| Ipamorelin acetate | 503B | Sep 29, 2023 |
| Kisspeptin-10 | 503A | Sep 29, 2023 |
Source and FDA's stated safety concerns for each: [FDA]
Peptides nominated but withdrawn
FDA's page says these were previously in category 2 and were withdrawn by the nominators. FDA still publishes its safety concerns for them, commonly including possible immunogenicity, peptide-related impurities, and no or limited safety information for the proposed routes. [FDA]
AOD-9604BPC-157Cathelicidin LL-37CJC-1295Dihexa acetateEmideltide (DSIP)EpitalonGHK-Cu (injectable routes)Ipamorelin acetateKPVPEG-MGFMelanotan IIMOTs-CSelank acetate (TP-7)Semax (heptapeptide)Thymosin-alpha 1Thymosin beta-4 fragment (TB-500)