Retatrutide chemical structure explained: molecular formula, peptide sequence, CAS number, and how this triple GLP-1/GIP/glucagon agonist works.
Retatrutide is a synthetic 39-amino acid peptide designed as a triple agonist of the GLP-1, GIP, and glucagon receptors. Its chemical structure features a modified peptide backbone plus a fatty-acid side chain that prolongs its action in the body. That triple-receptor design is what makes retatrutide structure different from earlier weight-loss drugs.
Retatrutide Chemical Structure at a Glance
Retatrutide, also known by its development code LY3437943, is not a small molecule. It is a large, modified peptide. Its reported retatrutide molecular formula is C221H342N46O68, and its molecular weight is approximately 4,731.3 g/mol. These values come from published patent and research data; always verify against a primary source if you need exact figures.
The table below summarizes the key identifiers for the retatrutide molecule.
| Property | Value |
|---|---|
| Chemical name | Retatrutide (LY3437943) |
| Molecular formula | C221H342N46O68 |
| Molecular weight | ~4,731.3 g/mol |
| CAS number | 2381089-83-2 |
| Peptide length | 39 amino acids |
| Receptor targets | GLP-1, GIP, glucagon |
| FDA status | Not approved; investigational |
Understanding the Retatrutide Molecule: Backbone and Side Chain
The retatrutide molecule is built from a 39-amino acid chain. That chain is not a natural human hormone; it is engineered to resist breakdown by DPP-4 enzymes and to bind multiple receptors at once. The exact retatrutide sequence is published in scientific literature and patents, but the key structural feature is the fatty-acid side chain.
Attached to the peptide backbone is a C20 fatty diacid moiety. This lipid tail allows retatrutide to bind tightly to albumin in the bloodstream. Albumin acts as a carrier, which slows renal clearance and gives the drug a half-life of about six days. That is why retatrutide can be dosed once weekly in trials.
If you are asking what is retatrutide made from, the answer is chemical synthesis. It is produced through solid-phase peptide synthesis, not extracted from plants or animals. The process builds the chain amino acid by amino acid and then adds the fatty-acid side chain.
Retatrutide Mechanism of Action: The Triple G Agonist
The retatrutide mechanism of action is often called “triple G” because it activates three receptors: GLP-1, GIP, and glucagon. This is different from semaglutide, which targets GLP-1 only, and tirzepatide, which targets GLP-1 and GIP. The addition of glucagon receptor activity is what makes retatrutide triple G.
Here is how each receptor contributes:
- GLP-1 (glucagon-like peptide-1): Reduces appetite, slows stomach emptying, and improves glucose-dependent insulin release.
- GIP (glucose-dependent insulinotropic polypeptide): Enhances insulin sensitivity and may improve fat metabolism.
- Glucagon: Increases energy expenditure and promotes lipolysis, though it can also raise blood glucose if not balanced.
Because retatrutide moa combines these three pathways, researchers hope it can produce greater weight loss than single- or dual-agonist drugs. However, the glucagon component requires careful monitoring of blood sugar and liver enzymes in studies.
How Retatrutide Works Compared to Other Incretins
To see how retatrutide works in context, compare its receptor profile with other popular agents. The table below shows the differences.
| Drug | GLP-1 | GIP | Glucagon | Typical dosing |
|---|---|---|---|---|
| Semaglutide | Yes | No | No | Once weekly |
| Tirzepatide | Yes | Yes | No | Once weekly |
| Retatrutide | Yes | Yes | Yes | Once weekly (investigational) |
| Cagrilintide | No (amylin analog) | No | No | Once weekly (investigational) |
When comparing cagrilintide vs retatrutide, the main distinction is that cagrilintide mimics amylin, a different satiety hormone, while retatrutide hits three incretin-related receptors. A common search is is retatrutide a glp-3, but there is no GLP-3 receptor; retatrutide is simply a triple agonist.
What Does Retatrutide Do? Clinical and Practical Context
Retatrutide is being studied for obesity and type 2 diabetes. In phase 2 trials, participants taking higher doses lost substantial weight over 48 weeks. However, retatrutide is not FDA-approved for any use, and it is not available by prescription. Any online seller offering retatrutide is selling an unapproved research chemical.
People often ask how long does retatrutide take to work. In trials, appetite changes appear within the first few weeks, but meaningful weight loss accumulates over several months. There is no approved retatrutide brand name yet, as the drug remains in phase 3 development.
In clinical trials, retatrutide dosage has ranged from 1 mg to 12 mg once weekly, with doses escalated gradually to reduce side effects. Common side effects in studies include nausea, diarrhea, vomiting, and constipation. Because the drug affects glucagon, researchers also monitor heart rate, liver health, and blood glucose.
Safety, Legal Status, and What to Know
Retatrutide is an investigational drug. It has not been reviewed by the FDA for safety, efficacy, or quality. Purchasing retatrutide online is risky because the product may be impure, incorrectly dosed, or not retatrutide at all. If you are considering any weight-loss medication, talk to a licensed healthcare professional.
The chemical structure of retatrutide is fascinating, but structure alone does not guarantee safety. The triple agonist design may offer benefits, yet it also introduces unique risks that require clinical supervision. Always rely on approved treatments or enrolled clinical trials rather than gray-market peptides.
Frequently Asked Questions
What is the chemical formula of retatrutide?
The reported molecular formula for retatrutide is C221H342N46O68, with a molecular weight of about 4,731.3 g/mol. Its CAS number is 2381089-83-2. These values come from published research and patent data, so verify against a primary source if you need exact figures.
Is retatrutide a GLP-3?
No, there is no GLP-3 receptor. Retatrutide is a triple agonist that activates GLP-1, GIP, and glucagon receptors. Some people use the term “GLP-3” informally, but it is not a scientific classification.
How does retatrutide work differently from tirzepatide?
Tirzepatide targets GLP-1 and GIP, while retatrutide adds glucagon receptor activity. That third target may increase energy expenditure and fat breakdown. Retatrutide is still investigational and is not FDA-approved for any use.
This page provides educational research information and does not replace medical advice, diagnosis, or treatment.