The 21 Peptides Checked Against FDA's Own Pages: Category, Dates and FDA's Risk Wording (2026)

All 21 compounds checked have an entry on FDA's page for bulk drug substances that may present significant safety risks, which carries a "Content current as of" date of 04/22/2026 (REG-124). Five of the 21 also appear on the agenda of an FDA advisory committee meeting planned before the end of February 2027 (REG-067, REG-066). One is named in a captured FDA warning letter (REG-005).

Updated October 28, 2026.

What did this check cover?

This article checks 21 compound names against FDA pages captured on 2026-10-08, so that a founder can see FDA's wording for each name in one table. Each row of the table records the FDA list or category, the page date, FDA's risk statement, any mention on the advisory committee agenda, and any mention in a captured FDA warning letter (REG-124, REG-067, REG-005). In plain terms, the table collects what the captured FDA pages say about each name (REG-124, REG-067, REG-005). Look up each name you sell in that table and compare the row with your own product pages and records. This article says nothing about a name that is not among the 21.

The names checked are ibutamoren, Kisspeptin-10, GHRP-2, GHRP-6, ipamorelin, AOD-9604, BPC-157, LL-37, CJC-1295, dihexa, emideltide, epitalon, GHK-Cu, KPV, PEG-MGF, Melanotan II, MOTs-C, selank, semax, thymosin alpha 1 and the thymosin beta-4 fragment (also known as TB-500 (REG-104)). FDA writes some of these names in a longer form, such as ipamorelin acetate (REG-083) and dihexa acetate (REG-092). In plainer words, FDA's own spelling of a name can be longer than the common one (REG-083, REG-092). This check covers the names on this list, and a name outside it needs its own search of FDA's pages.

What does this article not say?

This article does not describe what any compound does. FDA's category 2 page states that bulk drug substances that may present significant safety risks "have been placed in category 2 under the interim policies" (REG-033). In plainer words, the FDA wording this article quotes is about which compounding category FDA places a substance in (REG-033). Treat each row as a record of what FDA's page says and check your own claims against that wording.

Where FDA's own risk statement mentions a human effect, the statement is quoted verbatim and not rephrased. The quotes appear in marked paragraphs or table cells, each with a link to the FDA page. One example is the ibutamoren statement, which FDA words as a safety risk (REG-035). Read that sentence on FDA's page before you reuse any part of it.

Where a column has nothing for a compound, the table says "no entry". That phrase means the sources captured for this guide contain no entry in that group. When you read an empty cell, do not treat it as a statement of status either way. The captured sources do not say whether a compound with no entry in a column is regulated.

This article reports what the sources say and gives no legal advice. Each statement carries a ledger id so that a reader can check it against the source page. If you have a legal question about these pages, talk to a licensed attorney. This article does not say what any law requires of you.

Which FDA pages are the sources, and how old are they?

Four FDA pages carry the facts in this article, and each shows a date for its content (REG-124, REG-121, REG-136, REG-144). Each page shows a "Content current as of" date, and the table below lists them as captured on 2026-10-08 (REG-124, REG-121, REG-136, REG-144). The category 2 safety risks page is dated 04/22/2026 (REG-124). The risk statements in the main table come from that page (REG-124, REG-041). Before you rely on any row, open the page and compare its current text with the wording in this article.

FDA's NuScience Peptides LLC letter carries reference number 733652 (REG-180), and its Peptide Partners LLC letter carries reference number 735063 (REG-192). Each letter asks for its reference number in the response subject line (REG-178, REG-190). In plain terms, a response to either letter is identified by that letter's reference number (REG-178, REG-190). If you want to read either letter, search FDA's warning letter pages for its reference number.

What do FDA's categories say?

FDA's 503A page describes an interim policy covering certain bulk drug substances that cannot otherwise be used under section 503A (REG-112). The page says the policy describes three categories of nominated bulk drug substances (REG-113). In plain terms, FDA sorts these nominated substances into three groups under that policy (REG-113). Find the category for a compound before you read FDA's wording about it. The captured sources do not say how the categories apply to any product a seller lists.

FDA's 503A page says FDA has identified significant safety risks relating to the use of these substances in compounding pending further evaluation (REG-115). The page (FDA 503A page) words it this way: "These substances were nominated with sufficient supporting information to permit FDA to evaluate them, and they may be eligible for inclusion on the 503A bulks list. However, FDA has identified significant safety risks relating to the use of these substances in compounding pending further evaluation and, therefore, does not intend to adopt the policy described for the substances in category 1." (REG-115). In plain terms, FDA says it has identified significant safety risks for these substances in compounding and does not intend to adopt the category 1 policy for them (REG-115). Compare the wording FDA used with any statement your own pages make about these substances. The captured sources do not say how FDA's further evaluation will end.

FDA states it does not intend to take action against a compounder for compounding drugs using category 1 bulk drug substances, provided that the conditions described in the guidance document are met (REG-031). The category 2 page states that bulk drug substances that may present significant safety risks have been placed in category 2 under the interim policies (REG-033). Unlike category 1 (REG-031), category 2 carries FDA's statement that it would consider taking action against a compounder under its general enforcement policies (REG-030). Check which category FDA lists for a name before you rely on any statement about it.

Category 3

FDA's 503A page says category 3 substances may be eligible for inclusion on the 503A bulks list but were nominated with insufficient supporting information for FDA to evaluate them (REG-117, REG-200). It adds that these substances are not eligible for the policy that applies to substances in category 1, and that FDA would consider taking action against a compounder under its general enforcement policies (REG-200). In plain terms, FDA describes category 3 by the supporting information that came with the nomination (REG-117, REG-200). Compare the category 3 wording with the category 2 wording above when you read a row. The captured sources do not say that any compound in the table is in category 3.

FDA's three categories of nominated bulk drug substances

The table: 21 compounds, one row each

FDA's category 2 page states that bulk drug substances that may present significant safety risks "have been placed in category 2 under the interim policies" (REG-033). The page carries the line "Content current as of: 04/22/2026" (REG-124). A PCAC entry in the table means FDA's meeting page lists the compound among the substances the committee "will discuss" (REG-067). In plainer words, the table records each compound's category 2 wording and whether FDA's meeting page lists it for committee discussion (REG-033, REG-067). Scan the columns for each name you sell and compare them with your own records.

FDA's category 2 page states that "FDA has not identified any human exposure data" for drug products containing dihexa acetate, KPV or the thymosin beta-4 fragment (FDA category 2 page) (REG-044, REG-048, REG-055). For dihexa acetate and KPV, the sentence ends "administered via any route of administration" (REG-044, REG-048). In plainer words, FDA's page says FDA has not identified human exposure data for these three compounds, and for dihexa acetate and KPV the page applies that finding to any route (REG-044, REG-048, REG-055). Check each row's ids against the source page before you reuse a statement.

Which compounds have a date added on FDA's category 2 page?

FDA's category 2 page has a table headed "Date added to category 2" (REG-074). Ibutamoren mesylate, Kisspeptin-10, GHRP-2, GHRP-6 and ipamorelin acetate appear in that table in the captured entries (REG-082, REG-084, REG-080, REG-081, REG-083). The page lists each with the 503A category, the 503B category, or both (REG-082, REG-084, REG-080, REG-081, REG-083). Look up any other name you sell on the page itself, because the captured entries do not cover it in this table.

FDA's category 2 page lists a date added for each of these substances (REG-082, REG-084, REG-080, REG-081, REG-083). Ibutamoren has two dates because FDA lists it under both 503A and 503B (REG-082). The other four each carry one date and one category (REG-084, REG-080, REG-081, REG-083). The table below gives the dates as FDA lists them, from FDA's category 2 page (FDA category 2 page). Compare the date for any name you sell with the page's current text.

AOD-9604 appears on FDA's category 2 page under the headings "Bulk drug substance" and "Potential significant safety risks", unlike the headings that include "Date added to category 2" (REG-088, REG-074). In plain terms, that part of the page gives the substance and the potential risk (REG-088). The captured entries give no date added for the compounds outside the five above. Do not infer a date for them from the table above.

What does "nominated but withdrawn" mean on that page?

FDA's category 2 page lists some substances as nominated but withdrawn, and ipamorelin acetate appears both there and in the category 2 table (REG-034, REG-201, REG-096). The page states that this list of bulk drug substances previously in category 2 of the interim policies were withdrawn by the nominators (REG-034). For ipamorelin, the page shows the substance under the heading "Bulk drug substances nominated but withdrawn" and says it also appears in the table above because it is in category 2 under the 503B interim policy (REG-201, REG-096). In plain terms, FDA's page lists ipamorelin acetate in both places (REG-201, REG-096). Check the page itself for the heading above any other name you sell.

FDA's category 2 page shows AOD-9604 and the thymosin beta-4 fragment under the headings "Bulk drug substance" and "Potential significant safety risks" (REG-088, REG-104), while ipamorelin acetate also appears under "Bulk drug substances nominated but withdrawn" (REG-201). In plain terms, FDA's page shows ipamorelin acetate under a withdrawn heading as well as in the category 2 table (REG-201, REG-096). Open the page to see how FDA headed the rows for any other name you sell.

How does FDA's risk wording group the 21 compounds?

FDA words the ibutamoren risk as "significant safety risks" (REG-035), the immunogenicity risks as "may pose risk" or "may pose significant risk" (REG-036, REG-040), and the dihexa entry as no identified human exposure data (REG-044). The table below quotes these sentences from FDA's category 2 page (FDA category 2 page). In plain terms, FDA uses the same immunogenicity sentence for several compounds and varies it between "may pose risk" and "may pose significant risk" (REG-036, REG-040). Compare the pattern for a name you sell with the table row.

FDA words the risk for AOD-9604, PEG-MGF, MOTs-C and thymosin-alpha-1 as "may pose significant risk for immunogenicity" (REG-040, REG-049, REG-051, REG-054). For dihexa acetate, KPV and the thymosin beta-4 fragment, FDA writes "FDA has not identified any human exposure data" (REG-044, REG-048, REG-055). The thymosin beta-4 fragment also has a risk sentence (REG-104, REG-055). In plain terms, FDA's page gives that fragment both statements (REG-104, REG-055). Read both of the fragment's statements on FDA's page rather than one.

How FDA words the risk across the 21 compounds

Which compounds are on the advisory committee agenda?

FDA's meeting page announces an advisory committee meeting before the end of February 2027 (REG-066). The page's date is 04/15/2026 (REG-136). The page's agenda lists bulk drug substances being considered for inclusion on the 503A bulks list (REG-067). In plain terms, the page tells a reader that a meeting is planned and what it will discuss (REG-066, REG-067). Check the page for any change to the meeting plan.

FDA's meeting page names five compounds for discussion (REG-125, REG-126, REG-127, REG-128, REG-129). FDA's meeting page (FDA meeting page) states: "The Committee will discuss the following bulk drug substances being considered for inclusion on the 503A bulks list: Cathelicidin (LL-37) GHK-Cu Dihexa acetate Melanotan II Mechano Growth Factor, Pegylated (PEG-MGF)." (REG-067). The agenda lists Cathelicidin (LL-37), GHK-Cu, Dihexa acetate, Melanotan II and PEG-MGF (REG-125, REG-126, REG-127, REG-128, REG-129). In plain terms, FDA describes these substances as being considered for inclusion on the 503A bulks list (REG-067). Compare that wording with any statement on your own pages about these substances.

FDA's meeting page does not yet give a time or location (REG-130). The same page says the meeting time and location "will be scheduled in the coming months" (REG-130). It says FDA intends to publish a Federal Register notice and establish a docket for public comment on this meeting in the near future (REG-131). In plain terms, the page gives no meeting time or location and says a notice and a docket are intended in the near future (REG-130, REG-131). Check the page for the Federal Register notice and the docket before you plan around the meeting.

FDA's meeting page says advisory committees make non-binding recommendations to the FDA based on the expertise of their members (REG-132). The committee page says the Committee provides advice on scientific, technical, and medical issues concerning drug compounding under sections 503A and 503B (REG-056). In plain terms, the pages describe the committee as giving advice and recommendations to FDA (REG-132, REG-056). Read the agenda as a list of topics for advice and check FDA's page for any outcome.

FDA's meeting page names LL-37, GHK-Cu, dihexa acetate, Melanotan II and PEG-MGF as the substances the Committee will discuss (REG-067). The committee page carries the headings "Pharmacy Compounding Advisory Committee 2027 Meeting Materials" and "Pharmacy Compounding Advisory Committee 2026 Meeting Materials" (REG-137, REG-138). The captured sources do not say which meeting materials heading holds documents on those compounds. In plain terms, the committee page has meeting materials headings for 2027 and 2026 (REG-137, REG-138). Look under the committee page's meeting materials headings for any documents on a name you sell.

Which compounds do the captured warning letters name?

FDA's NuScience letter names ipamorelin through a product name (REG-005). The NuScience Peptides letter lists "Tesamorelin Ipamorelin Blend" among products it calls unapproved new drugs under section 505(a) (REG-005). The Peptide Partners letter lists semaglutide, tirzepatide, retatrutide, SS-31, tesamorelin, PT-141 and a reconstitution solution product (REG-017). Unlike the NuScience letter (REG-005), the Peptide Partners product list (REG-017) has no product named for any compound in this article. Check any product name on your own pages against the names FDA listed in these letters.

A warning letter entry in the table means FDA's NuScience letter names that compound inside a product name, as in "Tesamorelin Ipamorelin Blend" (REG-005). The letter lists that product among products it calls unapproved new drugs under section 505(a) (REG-005). In plain terms, the column records that FDA cited a seller for a product whose name includes the compound (REG-005). Check the letter itself for its full wording.

FDA's NuScience letter asks for a response "within fifteen (15) business days of receipt of this letter" (REG-068). FDA's NuScience Peptides warning letter (FDA warning letter 733652) states: "Failure to adequately address violations may result in regulatory or legal action without further notice including, without limitation, seizure and injunction." (REG-016). In plain terms, the letter asks for a response within fifteen (15) business days and says failure to adequately address violations "may result in regulatory or legal action without further notice" (REG-068, REG-016). Read the letter itself for its response instructions.

What the NuScience letter said about "research use" labels

FDA's NuScience letter sets the seller's research use labeling against evidence from the seller's website (REG-015, REG-014). The letter (FDA warning letter 733652) states: "Despite statements on your product labeling marketing your products “for laboratory, research, and analytical use” and “not intended for human or veterinary use,”" and "evidence obtained from your website establishes that your products are intended to be drugs for human use" (REG-015, REG-014). The Peptide Partners letter refers to "for research use only" labels (REG-026). In plain terms, both letters set label statements against statements drawn from the seller's website (REG-015, REG-014, REG-026, REG-025). Compare your own label wording with your own website wording.

What else do the 503A pages say that a seller should read?

FDA's 503A page ties bulk drug substances to a valid certificate of analysis and urges compounders to know their supplier (REG-029, REG-107). The page says bulk drug substances must be accompanied by a valid certificate of analysis and must have been manufactured by an establishment registered with FDA under section 510 of the FD&C Act (REG-029). The same page states: "The agency urges compounders to know your bulks supplier" (REG-107). In plain terms, the page asks for a certificate of analysis and urges compounders to know their supplier (REG-029, REG-107). Compare the certificates of analysis you hold against the wording on FDA's page.

The 503A page also lists conditions for bulk drug substances used by state-licensed physicians and pharmacists compounding under section 503A (REG-105). FDA's 503A page (FDA 503A page) lists: "Comply with an applicable United States Pharmacopeia (USP) or National Formulary (NF) monograph if one exists, and the USP chapter on pharmacy compounding;" (REG-105) and "Are components of FDA-approved drug products if an applicable USP or NF monograph does not exist; or" (REG-106). In plain terms, one condition refers to a USP or NF monograph and the other to a case where no monograph exists (REG-105, REG-106). Check the page for the full list of conditions.

How the 503A bulks list has developed

FDA solicited nominations for bulk drug substances in 2015 (REG-108). A final regulation issued in February 2019 placed six substances on the list and identified four others it did not place (REG-109). A proposed regulation issued in September 2019 proposed to place five substances on the list and not to place 26 other substances (REG-110). In plain terms, the page reports a final and a proposed regulation with those numbers (REG-109, REG-110). Check FDA's page for the current state of the list.

FDA says it will continue to evaluate nominated substances on a rolling basis through notice-and-comment rulemaking (REG-111). It says it does not intend to place bulk drug substances nominated on or after January 7, 2025, into these categories (REG-032). It also says compounders and other interested parties may continue to nominate substances for inclusion on the 503A bulks list (REG-120). In plain terms, FDA says substances nominated on or after January 7, 2025 are not placed into these categories and that nominations may continue (REG-032, REG-120). Check the page for its latest nomination wording.

What could the sources not tell us?

The sources captured for this guide leave gaps that affect how far the table can be read. The list below names four of them. The FTC Health Products Compliance Guidance page could not be read on 2026-10-08, because the capture returned an Akamai block page (REG-058). Read the table with those limits in mind, and consult the FDA pages directly for anything the list names.

• The captured entries give no date added for 16 of the 21 compounds, as covered above.
• The captured entries do not state the table heading above 15 of the second-table rows.
• The FTC Health Products Compliance Guidance page could not be read on 2026-10-08, because the capture returned an Akamai block page (REG-058). It is not used here.
• The ledger holds two FDA warning letters, not a full search of every FDA letter.

FAQ

Is each of the 21 compounds on the FDA safety risks page?

Each of the 21 has an entry on the category 2 page in the captured evidence, shown in the table above with its ledger ids. The page carries "Content current as of: 04/22/2026" (REG-124).

What does FDA's wording say about ibutamoren?

The page lists it as category 2 for 503A (added September 29, 2023) and for 503B (added December 29, 2022) (REG-082). FDA's wording is quoted below.

FDA's category 2 page: "Ibutamoren mesylate poses significant safety risks due to the potential for congestive heart failure in certain patients." Source: FDA category 2 page (REG-035)

For which compounds does FDA say it has not identified human exposure data?

FDA's category 2 page says it has not identified any human exposure data for drug products containing dihexa acetate (REG-044), KPV (REG-048), or Thymosin Beta-4, Fragment (REG-055).

Which compounds are on the 2027 advisory meeting agenda?

LL-37, GHK-Cu, dihexa acetate, Melanotan II and PEG-MGF are listed as being considered for inclusion on the 503A bulks list (REG-067). FDA says the meeting will be before the end of February 2027 (REG-066).

Does a warning letter mean a compound is illegal?

The captured sources show FDA writing to named sellers about named products. The NuScience Peptides letter concerns products FDA calls unapproved new drugs under section 505(a), including a product named "Tesamorelin Ipamorelin Blend" (REG-005). The captured sources do not say anything about whether a compound is illegal.

What does "no entry" mean in the table?

It means the sources captured for this guide contain no entry for that compound in that group, and nothing more. It is not a statement about whether a compound is regulated.

Does this article say any of these compounds is safe or unsafe to use?

No. It quotes FDA's risk wording and does not describe what any compound does. FDA states that bulk drug substances used in compounding may present significant safety risks (REG-122).

Where should a founder go with a legal question about these pages?

Talk to a licensed attorney for your situation. This article reports what the sources say and gives no legal advice.

Sources

Talk to a licensed attorney for your situation.