Legal Status of Research Peptides in the United States (2026): Sale, Labelling and FDA Lists

In the United States in 2026, research peptides are sold as chemical reference materials labelled research use only (RUO), and the FDA 503A and 503B bulk-substance category lists, together with the FDA page that records BPC-157 and TB-500 as nominated but withdrawn and ipamorelin acetate in Category 2, concern compounding by pharmacies, physicians and registered outsourcing facilities. This page sets the labelling facts beside the dated FDA list facts, gives the source for each one, and states no legal opinion.

What is the legal status of research peptides in the US in 2026?

Research use only (RUO) is a labelling designation: a chemical reference material sold under it is labelled and marketed solely for laboratory research, with no claim made for it beyond its chemical identity and quantity. This page records, with dates and sources, the FDA bulk-substance category lists and the labelling facts that apply to the sale of research peptides in the United States in 2026.

A Pepta Labs vial label carries three items and leaves out a fourth:

• Compound name: the catalog name of the peptide or other compound, as on its product page.
• Quantity: the supplier-stated nominal quantity, written in milligrams (for example 10 mg), which Pepta Labs does not independently verify.
• Research-use designation: the statement that the material is sold for laboratory research only.
• No lot or batch number: the label carries none, and the analytical report covers a sampled production run, not an individual vial.

In the words of the site's documentation facts: "Vial labels identify the compound, quantity and research-use designation. They do not carry lot or batch numbers."

What does "research use only" mean on a label?

"Research use only" is a designation printed on the label and listing of a chemical reference material to state that the material is sold for laboratory research and for nothing else. The designation is a statement by the seller about how the material is labelled and marketed; it is not a registration, a licence, a clearance or an FDA category.

The designation also does not make a research peptide a certified reference material. The Pepta Labs Terms state that products "are not certified reference materials or pharmaceutical reference standards" (Terms, section 6.4). Documentation for a Pepta Labs listing is an analytical report for a sampled production run, as set out further down this page.

On a Pepta Labs vial the designation sits beside the compound name and quantity. The same designation applies at the point of sale. Orders are placed from a registered account with a confirmed email address, buyers must be 21 or older, and buyers certify laboratory-research purpose at checkout. The site-wide notice states that every listing is sold for laboratory research only.

At Pepta Labs the designation appears on the vial label, in the product listing, in the checkout certification and in the compliance policy, which the Terms of Service incorporate. What a research peptide is, how it is made and how it is documented is covered in what research peptides are.

What can a research use only listing state?

Pepta Labs labels, markets and sells every listing only as a chemical reference material for laboratory research, and makes no claim about what any compound does. Product pages state chemical and commercial facts only.

• Compound name and supplier-stated nominal quantity.
• CAS Registry Number, molecular formula and molecular weight.
• Sequence, where one applies.
• Physical form.
• Reported HPLC purity for the sampled production run.
• Price and dry-storage information.

The same limits are written into the Terms (section 6.1) and the compliance policy, so the label, the listing and the contract describe a listing in the same terms.

What are the FDA 503A and 503B bulk drug substances category lists?

The FDA bulk drug substances category lists are two FDA documents, one under section 503A and one under section 503B of the Federal Food, Drug, and Cosmetic Act, that sort nominated bulk substances into three categories while FDA decides whether each belongs on the final bulks list for compounding.

• Category 1: bulk substances under evaluation by FDA.
• Category 2: substances FDA identified as raising significant safety concerns for compounding.
• Category 3: substances nominated without the information FDA needs to evaluate them.

The 503A lists apply to compounding by state-licensed pharmacies and physicians under section 503A. The 503B lists apply to compounding by outsourcing facilities registered with FDA under section 503B. Both lists concern compounding. The current 503A category list is dated May 14, 2026, and the current 503B category list is dated March 21, 2025.

FDA places each nominated entry separately, so one compound can sit in more than one category. On the March 21, 2025 503B list, GHRP-2 has one entry in Category 2 and a second entry in Category 1; on the May 14, 2026 503A list, one GHK-Cu entry is in Category 1.

FDA also keeps a separate compounding page on bulk drug substances that present significant safety risks ("Certain Bulk Drug Substances ... Significant Safety Risks"). Its content is current as of April 22, 2026, and it has two tables: "Bulk drug substances under category 2 of the interim policies" and "Bulk drug substances nominated but withdrawn". The withdrawn table covers substances that were previously in Category 2 and whose nominations the nominators withdrew.

Which peptides are on the lists in 2026?

On the FDA page dated April 22, 2026, four peptides remain in the Category 2 table: ipamorelin acetate (503B), kisspeptin-10 (503A), GHRP-2 (503B) and GHRP-6 (503B), each with a date added of September 29, 2023. Most other peptides once held in Category 2 now sit in the nominated-but-withdrawn table, which FDA describes as substances previously in Category 2 whose nominations were withdrawn. The table below gives the status of fifteen peptides, each under its FDA entry name, shortened where the FDA entry adds a name expansion or a route qualifier, with any entry on the two category lists.

The same April 22, 2026 page also lists MOTS-c, cathelicidin LL-37, dihexa acetate, epitalon and PEG-MGF as nominated but withdrawn, which brings the withdrawn table to 17 entries. Ipamorelin acetate is the one entry that appears in both tables, because its 503B Category 2 placement stands. Kisspeptin-10 is also in Category 2 of the May 14, 2026 503A list, and GHRP-2, GHRP-6 and ipamorelin acetate are in Category 2 of the March 21, 2025 503B list.

PT-141, sermorelin and tesamorelin are not named in either table of the April 22, 2026 page. Sermorelin acetate is in Category 1 of the March 21, 2025 503B list.

The compound-by-compound record, with each FDA entry name, lives in the FDA Category 2 peptides list for 2026. Vendor closures from 2024 to 2026 are a separate record, kept with vendors' own notices and archive captures in the peptide vendor shutdown tracker; this page records list status only.

Where are orders delivered?

Orders are accepted only for delivery to United States addresses. Compounds ship as sealed lyophilized powder at ambient temperature, without cold packs or insulated packaging, and shipping is free to United States addresses.

Most orders ship the next business day. Processing and delivery times are estimates, not guarantees. The shipping terms, including how a missing or damaged shipment is reported, are in the shipping section of the Terms, and storage of sealed vials on arrival is covered in the peptide storage guide.

How does Pepta Labs label and document its listings?

Documentation is a third-party analytical report for a sampled production run, not a lot-specific certificate. The testing Pepta Labs represents is stated in its documentation facts: "Independent third-party HPLC purity analysis and mass-spectrometry identity confirmation, commissioned through the purchasing group on a sampled production run from the source. Pepta Labs does not test in-house."

The analytical report states the purity by RP-HPLC and identity by mass spectrometry. Net peptide content is not reported per listing. Vials carry no lot or batch number, as set out in the label list at the top of this page.

The analytical report is sent by email on request before an order. Because testing is commissioned by the purchasing group, the client field may name the group or source rather than Pepta Labs, and supplier-identifying fields are redacted. Sterility, endotoxin or LAL, potency, pharmaceutical-grade, cGMP, contaminant-panel and vial fill-quantity testing are not claimed.

The testing and documentation page describes the arrangement in full, and reports are requested through the report request form. How to read one, field by field, is covered in how to verify a peptide COA. The compliance policy and the Terms of Service set out the same documentation limits in contract form.

Frequently asked questions

What does research use only mean?

Research use only is a labelling designation under which a chemical reference material is sold and marketed solely for laboratory research, with no claim made for it beyond its chemical identity and quantity; it is not a registration, a licence or an FDA category.

Are BPC-157 and TB-500 on the FDA Category 2 list in 2026?

On the FDA page dated April 22, 2026, both BPC-157 and TB-500 (as the thymosin beta-4 fragment LKKTETQ) appear in the table of substances nominated but withdrawn, not in the Category 2 table, and neither appears on the May 14, 2026 503A or March 21, 2025 503B category lists.

Which peptides remain in Category 2?

Ipamorelin acetate under the 503B policy, kisspeptin-10 under the 503A policy, and GHRP-2 and GHRP-6 under the 503B policy remain in the Category 2 table, per the FDA page dated April 22, 2026; all four carry a date added of September 29, 2023.

Which facilities do the 503A and 503B category lists apply to?

The 503A lists apply to compounding by state-licensed pharmacies and physicians under section 503A of the FD&C Act, and the 503B lists to compounding by outsourcing facilities registered with FDA under section 503B, per the FDA category lists dated May 14, 2026 (503A) and March 21, 2025 (503B).

Where does Pepta Labs ship?

Pepta Labs ships to United States addresses only, as sealed lyophilized powder at ambient temperature, with the analytical report for the sampled production run sent by email on request.

Are research peptides legal for minors to order?

Not at Pepta Labs: orders are placed from a registered account with a confirmed email and an electronic research-use certification, buyers must be 21 or older, and delivery is to United States addresses only; the research-use-only labelling described above applies to every listing.

Sources

• FDA, "Certain Bulk Drug Substances ... Significant Safety Risks", content current as of April 22, 2026 (fda.gov).
• FDA, 503A bulk drug substances category list ("Bulk Drug Substances Nominated ... Under Section 503A of the Federal Food, Drug, and Cosmetic Act"), updated May 14, 2026.
• FDA, 503B bulk drug substances category list ("Bulk Drug Substances Nominated ... Under Section 503B of the Federal Food, Drug, and Cosmetic Act"), updated March 21, 2025.
• Pepta Labs documentation facts, as published on the testing and documentation page; Pepta Labs Terms of Service, sections 6 and 8; Pepta Labs compliance policy.

All products are supplied for laboratory research use only and are not for human or animal use.