Chapter two of four # Fact-check: the claims, card by card Online listings make big claims. Each card below puts one claim next to what the sources show, how solid that evidence is, and where to read it yourself. About a six-minute read In this chapter: eight claims you may meet online. Read the ones that match what you saw, then take the answers to the vet. ## How to read a card Each card has a short grade. "Solid" means an official record settles it. "Thin" means the evidence is small, or comes from animals other than pet cats. Where a card says a study "was not found", it means a careful search came up empty. That is strong, but it is not a promise that nothing exists. Links marked PubMed go to the US government's free library of medical research papers. If a card matches a promise on a package you have, show both to the vet. ## The claims ### Claim you may see: "It's a peptide, and vets use peptides." **Solid: approval records** What the sources show: True for some approved cat medicines, such as insulin and cyclosporine. Not true of the four online ones (KPV, BPC-157, GHK-Cu and TB-500), which had no approval for any animal when checked. That is not the same as saying no vet ever uses them. It means there is no approval and no pet trial behind them. _Checked in September 2026._ - [FDA: Animal Drugs @ FDA database](https://animaldrugsatfda.fda.gov/adafda/views/#/search) ### Claim you may see: "It has been tested on animals." **Thin: lab animals only** What the sources show: The only BPC-157 work in dogs found was lab testing in healthy beagles, run to develop a human drug. Those dogs coped with it, but they were healthy lab dogs, not pets. They were also given a carefully made batch from the researchers, not a vial bought online whose contents nobody has checked. Coping with a substance in a lab study is not the same as it being safe for a cat. How the body handled BPC-157 also changed a lot between rats and dogs in that work, so a result in one animal does not carry over to another. No such figures exist for cats at all. _Checked in September 2026._ - [PubMed: lab study in rats and beagles](https://pubmed.ncbi.nlm.nih.gov/36588717/) - [PubMed: lab toxicity study including dogs](https://pubmed.ncbi.nlm.nih.gov/32334036/) ### Claim you may see: "Studies show it heals." **Thin: mostly rats and mice** What the sources show: Most BPC-157 research has been done on rats and mice. Checking one set of those rodent studies, a 2026 review concluded they do not make BPC-157 a proven treatment; more lab work is needed first. In people, a 2025 review found just three pilot studies, meaning small first tries, and said BPC-157 is still under study. No study of it as a treatment in pet cats was found. _Checked in September 2026._ - [PubMed: critical review of the rodent studies](https://pubmed.ncbi.nlm.nih.gov/42794771/) - [PubMed: review of the human evidence](https://pubmed.ncbi.nlm.nih.gov/40789979/) ### Claim you may see: "Research grade means lab-tested and pure." **Doubtful: tested products fell short** What the sources show: A "research use only" sticker does not settle anything: the FDA looks at the seller's claims, website and sales pitch to decide what the product is. When labs tested peptide products sold online for people, they found wrong amounts, impurities, and some seized samples with no peptide in them at all. No testing of peptides sold for cats or other pets turned up, so their contents are simply unknown. _Checked in September 2026._ - [PubMed: tests of vials sold online](https://pubmed.ncbi.nlm.nih.gov/39509151/) - [PubMed: tests of seized peptide products](https://pubmed.ncbi.nlm.nih.gov/33686802/) ### Claim you may see: "The FDA took BPC-157 off a danger list, so it is fine now." **False for pets** What the sources show: The "list" in this claim is an FDA page about raw ingredients that pharmacies might use in medicines for people. Someone once asked the FDA to consider BPC-157 for that use, then took the request back. The page, current as of April 22, 2026, records that; it is not an FDA clearance. Either way, that page covers medicines for people. It does not apply to medicines for cats at all. The same page says it may set off immune reactions in people, and that the FDA lacks the information to know whether it causes harm. _Checked in September 2026._ - [FDA: the human compounding page](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) ### Claim you may see: "It is natural." **Misleading** What the sources show: BPC-157 comes out of a lab; its design copies a fragment of a protein found in the stomach. TB-500 is also synthetic: a short stretch of the body's own thymosin beta-4 protein, rebuilt in a lab with a chemical tweak added. TB-500 first spread as a product sold for racehorses, and racing labs then designed drug tests to spot it in horses. Natural or not, the word says nothing about whether something suits a cat. _Checked in September 2026._ - [PubMed: racing lab paper on the racehorse product](https://pubmed.ncbi.nlm.nih.gov/23084823/) ### Claim you may see: "The human weight-loss shots are already here for cats." **Not yet: early studies** What the sources show: GLP-1 drugs are the family behind the human weight-loss and diabetes shots. They mimic a hormone made in the gut, one that raises insulin when blood sugar runs high and makes people feel full. As of September 30, 2026, no GLP-1 drug had FDA approval for cats or dogs. A slow-release GLP-1 implant for overweight cats started a study in pet cats in December 2025. The company has opened an FDA file that lets it run studies, the first step toward any approval, and nothing has been approved. Earlier small studies in diabetic cats gave mixed results, and reviewers say bigger studies are still needed. _Checked in September 2026._ - [PubMed: review of the cat diabetes research](https://pubmed.ncbi.nlm.nih.gov/38870560/) - [PubMed: trial in newly diabetic pet cats](https://pubmed.ncbi.nlm.nih.gov/26700409/) ### Claim you may see: "If it is fine for people, it is fine for a cat." **False: cats are different** What the sources show: A cat's liver is missing some of the tools that people and dogs rely on to clear certain drugs, so those drugs pile up. The FDA says acetaminophen, a common human pain pill, is fatal to cats. That research is about ordinary drugs, not peptides, so how cats handle these peptides is not known. _Checked in September 2026._ - [Journal review: how cats clear drugs](https://pmc.ncbi.nlm.nih.gov/articles/PMC3811070/) - [FDA: common questions about animal drugs](https://www.fda.gov/animal-veterinary/safety-health/frequently-asked-questions-about-animal-drugs) ## Recap - Some real cat medicines are peptides; the online ones had no approval for any animal. - The animal work on BPC-157 is in lab rodents and lab beagles, not pet cats. - No test of what is inside peptides sold for pets turned up. - Cats handle many drugs differently from people and dogs. [Next: the question list](/question-list/) --- catspeptides.com is an editor's prep sheet for cat owners on their way to the vet, written to be read and printed; nobody here examines animals, fills prescriptions or sells anything.