Peptides include some dog medicines, but the name alone proves nothing

What the word means

A few tiny building blocks joined in a string make a peptide. Those blocks are called amino acids; they also make proteins, materials in the body. Insulin is a peptide. Cyclosporine, a medicine for itchy skin, is another; its blocks form a ring.

The label "peptide" settles nothing about safety or legal status. An approved insulin and an unchecked online vial are both peptides.

Peptide medicines already approved for dogs

These are prescription medicines. In each case the vet sets the amount, and this page gives none.

• Insulin for dogs with diabetes. The FDA has approved two kinds for both dogs and cats: one taken from pigs, and one made for pets with the same building-block order as human insulin.
• Cyclosporine, for dogs with allergic skin disease and, as an eye ointment, for dogs with dry eye. Both uses carry FDA approval.
• Eye ointments holding bacitracin and polymyxin B, two peptide antibiotics, approved for eye infections in dogs and cats.
• Oxytocin, a body signal involved in birth, appears on some labels for dogs to help during delivery and after surgery to deliver puppies. Other oxytocin labels cover only horses and farm animals.
• ACTH tells two small glands near the kidneys to make cortisol, a hormone involved in stress. The FDA has approved an ACTH gel for dogs and cats. In December 2025 it also approved a lab-made copy for dogs. Vets use that copy to check how well those glands work.

Human peptide medicines a vet may use for a dog

Desmopressin copies the body's water-saving hormone. It is the main treatment for central diabetes insipidus in dogs, a condition unrelated to sugar diabetes that causes heavy drinking and urination. It is a human medicine, and no pet version holds FDA approval.

Glucagon raises blood sugar. One study of 11 dogs with an insulin-making tumor described vets giving it in hospital for dangerously low blood sugar. No glucagon product is approved for animals.

This off-label route covers only drugs the FDA has approved, for animals or for people, and only on a vet's say-so.

What dogs do not have

Gonadorelin, a copy of a brain hormone that steers fertility, is approved in the US for dairy cattle. No gonadorelin product is approved for dogs.

GLP-1 drugs copy a signal from the gut that raises insulin when blood sugar is high and helps people feel full. The FDA's searchable animal medicine list was checked on September 30, 2026. It held no approval for a GLP-1 weight or diabetes medicine for either dogs or cats.

The same kind of search came back empty for TB-500, KPV, BPC-157 and GHK-Cu. Those are the names that turn up most on listings, and the law crossings page explains what that gap means.

Map legend: every term on this site

Look up an unfamiliar word here, or use the search box to find it.

Adverse event

Any harmful or unexpected change after a medicine is given, including the medicine doing nothing.

Amino acid

A tiny building block. A short string of these blocks is a peptide; they also make proteins, materials in the body.

Animal Drugs @ FDA

The FDA's free online list of most approved animal medicines, searchable by name, ingredient or application number.

Antibody

A substance made by the body's defenses, called its immune system. It recognises something the body treats as an outsider. Making antibodies to a medicine does not, by itself, tell us whether the animal was harmed.

Bulk drug substance

The raw active powder a medicine starts from, before it becomes a finished product.

Client-owned dog

A pet that lives at home with its family, as opposed to a dog bred for a laboratory.

Collagen peptides

Small pieces of collagen, a material in skin and other body tissues, given in food as a supplement. They are a different product from research peptides given by injection.

Compounding

A pharmacist or vet mixing or reworking ingredients into a custom medicine for a single patient. The result is not FDA-approved.

Conditional approval

FDA permission, renewed a year at a time for up to five years, while a company finishes proving that a drug it has shown to be safe actually works.

Endotoxin

A poison left behind by bacteria, which can remain even after the bacteria are dead.

Enforcement discretion

The law still prohibits making a pet drug from raw powder. But the FDA generally leaves some medically needed, custom medicines alone if all its conditions are met. That choice is not approval or permission in law.

Extra-label use

An approved drug put to a use its label leaves out, on a vet's decision. It never stretches to an unapproved substance.

FDA

The US Food and Drug Administration, which decides which medicines for people and animals may be sold.

Half-life

The time the body takes to clear half of a drug from the blood.

Immune reaction

The body's defenses responding to a substance as an outsider. They may make antibodies, substances that recognise it. This term alone does not tell an owner what signs to expect.

INAD file

The file a company opens with the FDA to begin studying a new animal drug. Opening one is not an approval.

Intended use

What a product is really sold to do, judged from the seller's claims and the way it is sold. It decides whether something counts as a drug.

Major species

The seven animals the FDA treats as main markets: dogs, cats, horses, cattle, pigs, chickens and turkeys.

NADA and ANADA

The application numbers printed on an approved animal drug: NADA for a brand, ANADA for a generic.

NDC number

A product code showing that a drug was listed with the FDA. It does not show approval.

Purpose-bred dog

A dog bred for research and kept in controlled conditions, usually healthy.

Research use only

A label some sellers print on chemicals. The FDA looks past it to how the product is actually sold.

Target animal safety study

Before approval, researchers usually test healthy animals of the kind the drug is meant for. They look for harm, including when larger amounts are given for longer than planned. That checks how much room there is between the planned use and harmful effects; it cannot promise safety for every pet.

Unapproved animal drug

An animal medicine without any of the FDA statuses needed for legal sale: full approval, conditional approval or a place on its special list for small-market animals. Dogs cannot use that list. Selling an unapproved animal drug is illegal.

VCPR

The veterinarian-client-patient relationship: the vet has examined the animal, takes charge of its care and is reachable for follow-up.

Warning letter

A formal FDA letter telling a firm it appears to be breaking the law. It states the FDA's view, not a court ruling.