Semaglutide vs Tirzepatide vs Retatrutide
Semaglutide is a GLP-1 receptor agonist, tirzepatide is a dual GIP/GLP-1 agonist, and retatrutide is an investigational triple GIP/GLP-1/glucagon agonist. All are weekly subcutaneous injections used by clinicians for metabolic and weight management goals when appropriate after evaluation. Suitability and dose are decided by the prescribing clinician.
What's being compared
Investigational triple agonist (GIP, GLP-1, glucagon) discussed in published trials.
Side-by-side comparison
| Attribute | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Receptor target | GLP-1 receptor only | Dual GIP and GLP-1 receptors | Triple GIP, GLP-1, and glucagon receptors |
| Drug class | GLP-1 receptor agonist | Dual incretin agonist | Triple incretin/glucagon agonist |
| Common indications | FDA-approved finished products carry indications for type 2 diabetes and chronic weight management; clinicians decide patient fit. | FDA-approved finished products carry indications for type 2 diabetes and chronic weight management; clinicians decide patient fit. | Investigational; published trials have explored metabolic and weight-management contexts. No FDA-approved indications at the time of writing. |
| Typical dosing schedule | Once weekly subcutaneous, titrated by clinician | Once weekly subcutaneous, titrated by clinician | Once weekly subcutaneous in trial protocols |
| Route of administration | Subcutaneous injection | Subcutaneous injection | Subcutaneous injection |
| Regulatory status | Branded finished products are FDA-approved; compounded versions are not FDA-approved. | Branded finished products are FDA-approved; compounded versions are not FDA-approved. | Investigational; no FDA-approved finished product at the time of writing. |
| Compounded availability | Available from 503A/503B compounding pharmacies on patient-specific prescriptions when clinically appropriate. | Available from 503A/503B compounding pharmacies on patient-specific prescriptions when clinically appropriate. | Limited compounded availability; clinicians weigh the investigational status before considering use. |
| Evidence base | Largest published clinical literature of the three, including multi-year cardiovascular and metabolic trial programs. | Substantial published trial program covering glycemic and weight-management endpoints in adults. | Earlier-phase published trial data; long-term outcomes are not yet established in the public literature. |
| Typical clinician use case | Often the first GLP-1-class option clinicians consider when a single-receptor mechanism fits the picture. | Considered when a clinician wants the dual GIP/GLP-1 mechanism alongside the standard metabolic workup. | Considered only by clinicians comfortable with investigational therapies and with full informed consent. |
| Clinician monitoring | Baseline labs, weight and tolerability follow-up, GI side-effect screening. | Baseline labs, weight and tolerability follow-up, GI side-effect screening. | Closer monitoring given investigational status; clinician judgment central. |
Which one might fit?
Use the framings below as orientation only. The right therapy is determined by your prescribing clinician based on history, lab work, and the specifics of your situation.
Semaglutide is the longest-studied of the three and is often the starting point clinicians consider when a GLP-1-only mechanism is appropriate.
Tirzepatide adds GIP receptor activity to the GLP-1 mechanism and is one option clinicians may consider for that combined profile.
Retatrutide is still investigational. A clinician will weigh published trial data, regulatory status, and individual risk before considering it.
Talk to a clinician about which fits
Every Regen Therapy protocol is reviewed by a licensed clinician and dispensed by Wells Pharmacy Network only after evaluation. Start with a brief intake to see what makes sense for your situation.
Frequently asked questions
What is the main difference between semaglutide, tirzepatide, and retatrutide?
Semaglutide acts on the GLP-1 receptor, tirzepatide on both GIP and GLP-1, and retatrutide adds glucagon receptor activity on top of GIP and GLP-1. Each adds another receptor target to the prior class.
Are these medications interchangeable?
No. They target different combinations of incretin and glucagon receptors and have different titration schedules, side-effect profiles, and regulatory status. A clinician decides whether any is appropriate for a given patient.
How are they given?
All three are administered as once-weekly subcutaneous injections in the protocols clinicians use today. Specific titration schedules vary and are set by the prescribing clinician.
Is retatrutide FDA-approved?
At the time of writing, retatrutide is investigational and not FDA-approved as a finished product. Clinicians who consider it weigh the published trial evidence and the investigational status against the patient's situation.
Where do compounded versions come from?
Compounded versions are prepared by 503A or 503B compounding pharmacies on a patient-specific prescription. Compounded medications are not FDA-approved; clinical appropriateness is determined during a clinician evaluation.
How do clinicians choose between them?
Selection depends on clinical history, lab work, prior response to GLP-1 protocols, side-effect tolerance, and regulatory status. The choice is individualized after a clinician evaluation, not based on receptor count alone.