Contents
Key findings
- 1Four of the ten peptides we profile are FDA-approved drugs — semaglutide, tirzepatide, tesamorelin and bremelanotide (PT-141) — each for specific indications.
- 2Off-label prescribing of an approved drug is legal; the evidence for the off-label use can still be weak, as with tesamorelin outside HIV lipodystrophy.
- 3"Research use only" is a label, not a regulatory category. Products sold that way for human use are unapproved drugs.
- 4In September 2023 the FDA placed BPC-157, CJC-1295, ipamorelin and other popular peptides in category 2 of its compounding interim policies; by April 2026 most of those nominations had been withdrawn by the nominators, which removes the listing without making any of them eligible for compounding.
- 5The shortage-based allowance for compounded tirzepatide ended in late 2024 and for semaglutide in February 2025; the FDA has since acted against sellers of compounded and counterfeit versions.
Evidence level
The regulatory framework described here is documented in FDA statute, guidance and public lists. Individual peptide statuses were verified against those sources at the updated date and are re-checked quarterly.
Regulatory status
This article covers all six regulatory statuses used on this site; each peptide's own status is stated in the table below and on its profile.
"FDA-approved" and "not FDA-approved" sound like a verdict on whether something works. They aren't. Approval is a decision about a specific product for a specific use, based on evidence a company chose to submit. Understanding the categories in between — and how they changed for peptides in the last three years — is essential to reading any peptide claim.
The four categories, in plain terms
FDA-approved for a use. A company submitted a New Drug Application with clinical trials for a defined indication, and the FDA judged benefit outweighs risk for that indication. The product gets a label with the approved use, dosing, warnings and adverse reactions. Semaglutide (type 2 diabetes, weight management, cardiovascular risk), tirzepatide (diabetes, weight management, sleep apnoea), tesamorelin (HIV-associated lipodystrophy) and bremelanotide (HSDD in premenopausal women) are in this group[3][4].
Off-label use of an approved drug. Once a drug is approved, a licensed prescriber may use it for other conditions when they judge it medically appropriate[5]. This is legal and common across medicine. It does not mean the off-label use is supported by comparable evidence — sometimes it is, often it isn't. Tesamorelin for visceral fat in people without HIV is the clearest peptide example: same molecule, same mechanism, but the phase 3 trials were in a different population.
Investigational. The compound is being studied in humans under an Investigational New Drug application, in registered trials. It is not available for marketing. Full-length thymosin beta-4 (in wound and eye trials) is investigational; several newer incretin peptides are too.
Unapproved. No approval for any use. This is a large and heterogeneous bucket that includes: compounds whose development was abandoned (CJC-1295, ipamorelin); compounds that never entered formal development (BPC-157 in the U.S.); cosmetic ingredients that are also sold as injectables (GHK-Cu); and food ingredients that were never drugs (collagen peptides). "Unapproved" is where the evidence level label does the work, because regulatory status alone tells you nothing about the science.
The two labels every page here carries
What "research use only" actually means
Vendors sell peptides labelled "for research use only" or "not for human consumption". This is a labelling convention intended to keep the seller outside drug law by disclaiming human use. It is not an FDA category. When such a product is sold with the obvious expectation of human use, it is an unapproved drug — and, more practically, it is manufactured outside any pharmaceutical quality system. Our analysis of certificates of analysis covers what that means for what is actually in the vial.
What changed: compounding rules for peptides, 2023–2025
Two regulatory shifts explain most of the recent news around peptides.
1. Category 2, and then withdrawal. Under section 503A a pharmacy may compound from a bulk substance only if it has a USP or NF monograph, is a component of an FDA-approved drug, or appears on the 503A bulks list. While the agency evaluates nominations for that list it sorts them into three interim categories; category 2 holds substances for which FDA "has identified significant safety risks relating to the use of these substances in compounding pending further evaluation".
On 29 September 2023 the FDA placed a batch of popular peptides in category 2 — among them BPC-157, CJC-1295, ipamorelin acetate, AOD-9604, injectable GHK-Cu, kisspeptin-10, MOTS-c, epitalon, melanotan II, thymosin alpha-1 and thymosin beta-4 fragment (TB-500) — citing possible immunogenicity for certain routes of administration, complexities with peptide-related impurities and active-ingredient characterisation, and little or no safety data for the proposed routes. Clinics offering compounded versions had to stop.
The picture has since changed, and most coverage has not caught up. On the FDA list current at 22 April 2026, most of those peptides — including BPC-157, CJC-1295, TB-500, injectable GHK-Cu, AOD-9604, MOTS-c and epitalon — no longer appear in category 2 itself. They appear on an accompanying list of substances previously in category 2 whose nominations were withdrawn by the nominators. Ipamorelin acetate remains in category 2 under the 503B policy, as does kisspeptin-10 under 503A[1].
2. The end of the GLP-1 compounding window. When a drug is on the FDA's shortage list, compounders may prepare "essentially a copy" of it. Semaglutide and tirzepatide were both on that list during 2022–2024, which is why compounded versions became widely available through telehealth. The FDA declared the tirzepatide shortage resolved in late 2024 and the semaglutide shortage resolved in February 2025, closing that allowance. The agency has since warned about adverse events with compounded products, dosing errors, and counterfeit pens[2].
Where each profiled peptide sits (as of our last check)
| Peptide | US regulatory status | Notes | Overall evidence |
|---|---|---|---|
| Semaglutide | FDA-approved (3 indications) | Shortage resolved Feb 2025; compounding allowance ended | Established evidenceLarge RCTs, CVOT |
| Tirzepatide | FDA-approved (3 indications) | Shortage resolved late 2024 | Established evidenceLarge RCTs, head-to-head |
| Tesamorelin | FDA-approved (1 indication) | Off-label use common; evidence outside HIV small | Established evidencePhase 3 in HIV lipodystrophy |
| PT-141 (bremelanotide) | FDA-approved (1 indication) | Not approved for men; online 'PT-141' is not Vyleesi | Established evidenceTwo phase 3 RCTs |
| Collagen peptides | Food ingredient (GRAS) | No drug approval applies | Promising evidenceSeveral small RCTs |
| GHK-Cu | Cosmetic ingredient; injectable unapproved | Injectable form: category 2 nomination withdrawn | Preliminary evidenceSmall topical trials |
| CJC-1295 | Not approved; category 2 nomination withdrawn | Development discontinued; still not compoundable | Preliminary evidenceHormone-level studies only |
| Ipamorelin | Not approved; remains category 2 (503B) | Development discontinued | Preliminary evidencePhase 1; negative phase 2 (ileus) |
| BPC-157 | Not approved; category 2 nomination withdrawn | Never in U.S. clinical development | Preclinical evidenceAnimal studies |
| TB-500 | Not approved | Thymosin β4 (full length) investigational | Preclinical evidenceNone for fragment |
How to verify a status yourself
- Approvals and labels: search the drug name in Drugs@FDA[6]. If it isn't there, it isn't approved.
- Compounding eligibility: the FDA's 503A bulk substances category lists[1].
- Shortage status: the FDA Drug Shortages database.
- Trials: ClinicalTrials.gov, searching by intervention name; look for posted results, not just registrations.
If a seller's page says a peptide is "FDA-approved" without naming the indication and product, treat it as unverified.
Where to go next
- Regulation and approval hub — the running list, updated quarterly.
- Peptide purity, contamination and the limits of a certificate of analysis — the product-quality half of the problem.
- GLP-1 peptides: established uses versus emerging research — the approved drugs at the centre of the compounding story.
Frequently asked questions
- Is it legal to buy research peptides?
- Selling unapproved drugs for human use is illegal in the U.S.; the "research use only" label is an attempt to sit outside that. Possession rules vary. Legality aside, the products are unregulated and unverified.
- If a peptide isn't approved, does that mean it doesn't work?
- No. It means no one has submitted adequate evidence to the FDA — often because no adequate trials exist. Non-approval is not evidence of inefficacy, and it is not evidence of efficacy either.
- Can a doctor prescribe an unapproved peptide?
- A prescriber can use an approved drug off-label. They cannot lawfully prescribe an unapproved drug outside a clinical trial or expanded-access programme, and a pharmacy can only compound from a bulk substance that has a USP/NF monograph, is a component of an approved drug, or is on the 503A bulks list. None of the unapproved peptides we profile meets any of those conditions.
References
Numbered in order of first use. Study type is shown for every source; see our methodology for how we rank evidence.
- 1.
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (category 2 list) U.S. Food and Drug Administration, 2026.
Regulatory source
Result: Lists category 2 substances and, separately, substances previously in category 2 whose nominations were withdrawn by the nominators. BPC-157, CJC-1295, TB-500 and injectable GHK-Cu appear on the withdrawn list; ipamorelin acetate remains in category 2 under the 503B policy (added 29 September 2023).
↑ back to text - 2.
FDA's concerns with unapproved GLP-1 drugs used for weight loss U.S. Food and Drug Administration, 2025.
Regulatory source
Result: Describes shortage resolution for tirzepatide and semaglutide, adverse events reported with compounded products, and enforcement actions.
↑ back to text - 3.
FDA Approves New Drug Treatment for Chronic Weight Management, First Since 2014 U.S. Food and Drug Administration, 2021.
Regulatory source
Result: Semaglutide 2.4 mg approved for chronic weight management.
↑ back to text - 4.
FDA approves new treatment for hypoactive sexual desire disorder in premenopausal women U.S. Food and Drug Administration, 2019.
Regulatory source
Result: Bremelanotide (Vyleesi) approved.
↑ back to text - 5.
Understanding Unapproved Use of Approved Drugs "Off Label" U.S. Food and Drug Administration, 2018.
Regulatory source
Result: Explains that prescribers may use approved drugs for unapproved uses when judged medically appropriate.
↑ back to text - 6.
Drugs@FDA — FDA-approved drugs database U.S. Food and Drug Administration.
Regulatory source
Result: Primary source for approval status, dates and labels.
↑ back to text
Review status: Editorially reviewed against primary sources. This article was fact-checked against the primary sources listed in the references by our editorial team, and it has not been reviewed by a licensed clinician. It is educational content, not medical advice. Read our editorial policy and methodology. Spotted an error? Tell us.
