What does “peptide” actually mean?

Why the word covers different things.

Insulin is a peptide, and so are some medicines used for weight and diabetes care.

A peptide name alone cannot show that something works for your goal or has undergone review for use in people.

It helps to separate the broad word from the exact product. Ask for the full medicine name, along with the health problem it is intended to treat.

A medicine with FDA review.

The U.S. agency that reviews medicines is the Food and Drug Administration (FDA).

FDA-approved products include Ozempic and Wegovy, which contain semaglutide, and Mounjaro and Zepbound, which contain tirzepatide, as of September 2026. [b]

The FDA approves a particular medicine for particular uses. For example, semaglutide (Wegovy) has approved products, but a made-to-order medicine containing semaglutide does not share that approval.

A familiar medicine name is a starting point for a question. It is not a reason to assume a plan fits your health.

A medicine made to order.

Preparing a medicine to order for a particular need is called compounding. The medicine is called compounded, rather than a ready-made drug-company product. [a]

As of September 2026, these compounded products do not have FDA approval or the agency’s review before sale. [a]

Making medicine to order can be lawful when the rules are met. The FDA says it may help when an approved medicine cannot meet your need or is not available. [a]

For example, making a medicine to order may help someone who cannot swallow the ready-made tablet.

Federal law limits regular copying of ready-made medicines. A change that matters for one patient can be an exception; a lower price alone is not enough. [d]

Ask what change you need and which rule allows it. Read the made-to-order page for more about these limits.

A product with a research label.

As checked in September 2026, the FDA warns against weight-drug products sold with instructions for people to use them. Even a “for research purposes” label or one saying “not for human consumption” does not remove this warning. [c]

In this warning, the FDA describes the products as having unknown quality and a risk of harm. [c]

A label saying “for research purposes” does not replace a care visit. Talk with your own doctor or the health professional seeing you online about the exact proposed medicine.