What does GLP-1 stand for?

Glucagon-like peptide-1, a hormone released by the small intestine after eating. The medicines are GLP-1 receptor agonists — molecules that activate the same receptor the hormone does, engineered to last much longer in the body.

Is a GLP-1 a hormone or a drug?

Both terms are in use, which is the source of the confusion. GLP-1 is a naturally occurring hormone. The medicines are receptor agonists named after it, and they are not the hormone itself.

What is the difference between semaglutide and tirzepatide?

Semaglutide acts at the GLP-1 receptor. Tirzepatide acts at both the GLP-1 and GIP receptors, GIP being a second incretin hormone. They are different molecules rather than different generations of one.

Why does the same drug have different brand names?

Because the same molecule can be licensed for different indications, and each licence gets its own brand and label. Insurance coverage frequently follows the licence rather than the molecule, which is why one brand may be covered and another refused.

Are there GLP-1 pills?

One oral semaglutide tablet is marketed, using formulation chemistry that allows absorption. Most products in the class are injectable because peptides are generally broken down in the digestive tract.

What is a GLP-1?

GLP-1 stands for glucagon-like peptide-1. It is a hormone your small intestine already releases after you eat — everyone reading this makes it, and made it long before it became a drug class.

The medicines named after it are receptor agonists: molecules shaped to activate the same receptor the natural hormone does, but engineered to survive in the body far longer. Understanding that one distinction explains most of what follows.

GLP-1 isAn incretin hormone
Drugs areReceptor agonists
First approvedFor type 2 diabetes
WeDo not prescribe

The hormone, before it was a drug

GLP-1 is one of the incretins — hormones released by the gut in response to food that signal to the pancreas, the brain and the stomach. Its natural half-life is very short; enzymes in the blood break it down within minutes of release.

That brevity is precisely why it took decades to turn into a medicine. A hormone that disappears in minutes is not something you can give someone once a week. The drug class exists because chemists found ways to make a GLP-1-shaped molecule that resists that breakdown.

What a receptor agonist is

An agonist is a molecule that binds a receptor and activates it, the way the natural signal would. A GLP-1 receptor agonist is therefore not GLP-1 — it is a molecule that the GLP-1 receptor responds to, built to last long enough to be dosed on a practical schedule.

Semaglutide activates the GLP-1 receptor. Tirzepatide activates the GLP-1 receptor and the GIP receptor, GIP being a second incretin hormone. That is why tirzepatide is described as dual-acting and why it is a genuinely different molecule rather than a revision of the first.

Because they are peptides rather than small molecules, they are given by injection rather than swallowed, with one oral exception where formulation chemistry allows absorption.

One class, several different licences

This is the part that generates the most confusion. The same molecule can be sold under different brand names with different licensed indications and different packaging, and insurance responds to those licences differently even though the active ingredient is identical.

Semaglutide is sold under separate brands for type 2 diabetes and for weight management, plus an oral tablet form. Tirzepatide likewise carries separate brands for the two indications. The molecule does not change; the licence, the label and often the coverage do.

This matters practically because plans frequently exclude weight-management indications while covering the identical molecule prescribed for diabetes or for cardiovascular risk reduction. When people say a plan "covers Ozempic but not Wegovy", this is what they are describing.

Things called GLP-1 that are not approved medicines

Several newer molecules circulate in the same conversation without the same status. FDA has stated plainly that retatrutide and cagrilintide cannot be used in compounding under federal law, that they are not components of FDA-approved drugs, and that they have not been found safe and effective for any condition.

The agency has issued warnings to telehealth companies marketing unapproved drugs including retatrutide, to active pharmaceutical ingredient distributors selling GLP-1 drugs to compounders, and to outsourcing facilities repackaging retatrutide. It has also established an import alert covering GLP-1 active ingredients with potential quality concerns.

If a programme offers you something described as a next-generation GLP-1, ask directly whether it is an FDA-approved product.

Provenance

Sources

FDA — FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss — retrieved 2026-08-06
FDA — FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize — retrieved 2026-08-06

Questions

GLP-1: common questions

What does GLP-1 stand for?: Glucagon-like peptide-1, a hormone released by the small intestine after eating. The medicines are GLP-1 receptor agonists — molecules that activate the same receptor the hormone does, engineered to last much longer in the body.
Is a GLP-1 a hormone or a drug?: Both terms are in use, which is the source of the confusion. GLP-1 is a naturally occurring hormone. The medicines are receptor agonists named after it, and they are not the hormone itself.
What is the difference between semaglutide and tirzepatide?: Semaglutide acts at the GLP-1 receptor. Tirzepatide acts at both the GLP-1 and GIP receptors, GIP being a second incretin hormone. They are different molecules rather than different generations of one.
Why does the same drug have different brand names?: Because the same molecule can be licensed for different indications, and each licence gets its own brand and label. Insurance coverage frequently follows the licence rather than the molecule, which is why one brand may be covered and another refused.
Are there GLP-1 pills?: One oral semaglutide tablet is marketed, using formulation chemistry that allows absorption. Most products in the class are injectable because peptides are generally broken down in the digestive tract.

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