Retatrutide: what it is, how it is sold and how to track it

Updated 2026-10-15 · The Pep Planner

Retatrutide is one of the newest names in the GLP-1 conversation. This page covers what it is, where it stands and how to keep accurate records.

Educational overview for record keeping. Not medical advice, and no doses. Check the rules where you live.

What it is

Retatrutide is a triple agonist: a single peptide designed to act on three hormone receptors, GIP, GLP-1 and glucagon. Like other drugs in this group, it carries a fatty acid chain so it lasts longer in the body.

How it is usually sold

Research vials: freeze-dried powder labeled by milligrams per vial
Often called "reta" in forums; use the full name in your records
There is no approved retatrutide medicine to compare a vial against

Regulatory status

Retatrutide is investigational: it is being studied in clinical trials and is not approved as a medicine in the U.S. Vials sold "for research use only" are not approved for human use.

Storage basics

Sealed vials are usually kept cold and away from light. Mixed vials are typically refrigerated and used within a window you set from the vendor's guidance.

How The Pep Planner helps you track it

Record the mg per vial and lot when you add stock, and use the calculator when you mix so the strength is saved with that vial. If your protocol has phases, add each step so every change is kept in its history.

Common questions

How is retatrutide different from tirzepatide?

Tirzepatide acts on two receptors (GIP and GLP-1). Retatrutide adds a third, the glucagon receptor.

Does this page recommend an amount?

No. The Pep Planner is an organizer and tracker. We do not give dosing or medical advice.

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