FDA-approved peptides for cats: what is and isn't approved

Which peptide drugs are FDA-approved for cats?

Insulin is the clear example. Insulin is a peptide hormone: the Merck Veterinary Manual groups it with the protein and polypeptide hormones. FDA has approved insulin products for cats with diabetes, and they must be prescribed by a vet.

ProZinc was approved for cats in October 2009, for lowering high blood sugar and its signs in cats with diabetes mellitus. Vetsulin's label says "Approved by FDA under NADA # 141-236" and covers dogs and cats with diabetes mellitus.

FDA warns that compounded insulin has not been checked for safety and effectiveness and may vary in quality and strength. Ask your vet for an approved insulin if your cat is newly diagnosed.

Is BPC-157 FDA approved for cats?

No. BPC-157, TB-500, GHK-Cu and KPV are not approved for cats or any other animal. None of them is listed in FDA's Green Book. They are also not officially tested in cats. BPC-157 returns no PubMed results at all for cats.

FDA's position is simple. A product sold to treat disease in animals without approval is an unapproved drug. On 12 Nov 2024 FDA warned six sellers of seizure products for animals on those grounds. No peptide was named. We found no FDA action aimed at these peptides for animals, and that silence is not approval.

You may have read 2026 news about BPC-157 and compounding. An FDA advisory committee voted to recommend BPC-157 for a compounding list, and HHS published a draft enforcement policy that covers BPC-157, KPV and TB-500. Both are about compounding for people under prescription. Neither is an approval, and neither mentions animals. If you are thinking of using a product made for people, read our page on human peptides and cats.

The same goes for weight-loss drugs. GLP-1 drugs for cats are still in development. Our GLP-1 page has the current picture.

What does FDA-approved actually mean?

It means FDA reviewed the drug before sale and found it safe and effective for the species and use on its label. FDA also checks how it is made and labelled.

There are three legal routes for an animal drug: full approval, conditional approval, and indexing for some minor species. FDA calls anything outside those routes an unapproved animal drug. It says these products were never reviewed for safety or effectiveness, and may not be properly made, labelled or packaged.

Approval is specific to the species, and cats are a good example of why. Most peptide vials sold online are labelled "research only". Nobody at FDA checks them, so the label may not match what is inside. Our safety guide explains what that means for your cat.

How to check a cat product yourself

Start with the label, then confirm in FDA's database. It takes a few minutes.

• Look for "Approved by FDA under NADA # XXX-XXX" (brand) or "ANADA # XXX-XXX" (generic). A conditionally approved drug says so in a similar line.
• Search the trade name, ingredient or number in Animal Drugs @ FDA. FDA's Green Book lists approved animal drugs and is updated monthly.
• Check that cats are named on the label. A dog-only product is not approved for your cat.
• Do not be reassured by an NDC number, "Caution: Federal law restricts this drug" or "made in an FDA-registered facility". FDA says none of these proves a drug is legally marketed.
• No approval number, or a "research only" label? Treat the product as unapproved and ask your vet before giving it.

Can a vet use compounded or off-label drugs for my cat?

Yes, within limits, and the limits matter here. A federal law called AMDUCA lets vets use approved animal or human drugs in ways the label does not list. That needs a real vet-client-patient relationship, and the animal's health must be at risk without treatment. Owners may not do this on their own. AMDUCA does not allow compounding from raw active ingredients.

Compounding from bulk ingredients falls under FDA guidance GFI #256. FDA does not normally act against it when no other suitable treatment exists. The bulk-substance list covers office stock only. Compounding for one animal is a separate route with its own conditions. Neither route approves anything, and we found no vet compounding pharmacy offering these peptides.

What vets prescribe instead for common cat problems

For several problems that bring owners to peptides, there are approved drugs your vet can weigh up. These are examples, not a treatment plan. Your vet will choose based on your cat's tests, kidneys and history.

• Stiff, sore joints: see our arthritis page. FDA says no NSAID is approved for long-term use in cats. Solensia's label gained new safety information on 5 Oct 2026, warning that serious reactions can result in death. Ask your vet about the Client Information Sheet.
• Older cats: our senior cat and kidney disease pages cover what to check first.
• Mouth, gut and skin problems: start with stomatitis, IBD or wounds.

When to call your vet

Call your vet before you give your cat any product without an approval number. Never give your cat a human pain reliever. FDA states plainly that acetaminophen is fatal to cats.

If your cat is on a pain reliever and starts vomiting, has diarrhea, black or bloody stool, stops eating, becomes very tired, or has yellow gums or eyes, stop the medicine and call your vet now. If you think a product hurt your cat, tell your vet and report it to FDA.