What do GLP-1 receptor agonists actually do?
GLP-1 stands for glucagon-like peptide-1, a hormone naturally secreted by intestinal L-cells in response to food intake. It performs several metabolic functions: stimulating glucose-dependent insulin secretion, suppressing glucagon release, slowing gastric emptying, and signaling satiety in the brain.
GLP-1 receptor agonists are synthetic compounds that bind to and activate the GLP-1 receptor, mimicking and extending these effects. They work through the body's own hormonal pathways rather than forcing a non-physiological response — which is part of why this drug class produces meaningful appetite reduction without the cardiovascular risks associated with older stimulant-based weight management drugs.
The medications on the GLP-1 drug list differ primarily in their molecular structure, duration of action, receptor target specificity, and approved indications.
The complete GLP-1 drug list: approved agents
Semaglutide (Ozempic, Wegovy, Rybelsus)
Semaglutide is the most widely recognized entry on the GLP-1 drug list. It is a GLP-1 receptor agonist with a half-life of approximately one week, enabling once-weekly subcutaneous dosing in its injectable forms.
- Ozempic (injectable): FDA-approved for glycemic management in adults with type 2 diabetes. Doses of 0.5 mg, 1 mg, and 2 mg weekly. Also demonstrated cardiovascular risk reduction in the SUSTAIN-6 trial.
- Wegovy (injectable): FDA-approved for chronic weight management in adults with BMI ≥30, or ≥27 with at least one weight-related comorbidity. Maximum approved dose of 2.4 mg weekly. The STEP trials demonstrated average weight reduction of approximately 15%.
- Rybelsus (oral): FDA-approved for type 2 diabetes management. Available in 3 mg, 7 mg, and 14 mg daily doses. Requires strict administration protocol: taken on an empty stomach with no more than 4 ounces of plain water, 30 minutes before food or any other medications. Not currently approved for weight management at weight-focused doses.
Tirzepatide (Mounjaro, Zepbound)
Tirzepatide is the newest and most pharmacologically distinct entry on the GLP-1 drug list. It is a dual agonist that activates both the GLP-1 receptor and the GIP (glucose-dependent insulinotropic polypeptide) receptor. GIP is a second incretin hormone with complementary metabolic effects, and the dual agonism of tirzepatide appears to produce effects greater than either receptor pathway alone.
- Mounjaro: FDA-approved for glycemic management in adults with type 2 diabetes. Doses of 2.5 mg through 15 mg weekly.
- Zepbound: FDA-approved for chronic weight management. The SURMOUNT-1 trial demonstrated average weight reduction of approximately 20% at the 15 mg dose — meaningfully higher than semaglutide alone in direct comparison trials.
Liraglutide (Victoza, Saxenda)
Liraglutide was the first once-daily GLP-1 receptor agonist and remains on the GLP-1 drug list, though it has been largely superseded for weight management by once-weekly agents.
- Victoza: FDA-approved for type 2 diabetes. Daily injection, doses of 1.2 mg and 1.8 mg.
- Saxenda: FDA-approved for weight management. Daily injection up to 3.0 mg. Approval predated semaglutide for weight management and showed approximately 5–8% average weight reduction in trials — less than the weekly agents.
Dulaglutide (Trulicity)
Dulaglutide is a once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes management. It is not approved for weight management as a primary indication, though weight reduction is observed as a secondary effect.
Exenatide (Byetta, Bydureon)
Exenatide was the first GLP-1 receptor agonist to reach the market. Available in a twice-daily form (Byetta) and a once-weekly extended-release form (Bydureon BCise). Approved for type 2 diabetes. Rarely used today for new prescriptions given the efficacy profile of once-weekly agents.
| Drug (generic) | Receptor(s) | Weight Mgmt approved | Compounded via 503A |
|---|---|---|---|
| Semaglutide | GLP-1 | Yes (Wegovy) | Yes (shortage-dependent) |
| Tirzepatide | GLP-1 + GIP | Yes (Zepbound) | Yes (shortage-dependent) |
| Liraglutide | GLP-1 | Yes (Saxenda) | Uncommon |
| Dulaglutide | GLP-1 | No | Uncommon |
| Exenatide | GLP-1 | No | Uncommon |
Which GLP-1 drugs can be compounded?
Semaglutide and tirzepatide are currently available as compounded preparations through licensed 503A compounding pharmacies, accessible via telehealth platforms while the branded versions remain on FDA shortage lists.
Compounded semaglutide and compounded tirzepatide are not FDA-approved drugs. They are preparations of the active pharmaceutical ingredient (API) compounded by licensed pharmacies — they are not therapeutically equivalent to Wegovy, Ozempic, Zepbound, or Mounjaro. The availability of compounded versions is tied to the FDA shortage designation and may change as the branded supply situation evolves.
Liraglutide, dulaglutide, and exenatide are not currently widely available as compounded preparations through telehealth. Their once-daily or twice-daily dosing schedules and the availability of more effective once-weekly compounded alternatives make them uncommon choices for telehealth weight management programs.
How do you choose between the options on the GLP-1 drug list?
Choosing between semaglutide and tirzepatide — the two options available through compounded telehealth programs — involves several factors:
- Efficacy data: Clinical trial data suggests tirzepatide produces greater average weight reduction (approximately 20% at max dose) compared to semaglutide (approximately 15% at max dose). These are population averages; individual responses vary.
- Side effect profile: Both medications share a similar GI side effect profile (nausea, constipation, diarrhea). Individual tolerability differences between the two are real but not consistently predictable in advance.
- Cost: Tirzepatide is generally priced higher than semaglutide at comparable dose tiers through compounded telehealth platforms.
- Clinical history: Your prescribing clinician factors in your medical history, comorbidities, and prior medication responses when making a recommendation. This is not a decision to make based on marketing copy.
The right choice from the GLP-1 drug list for you is a clinical decision. A licensed clinician reviewing your specific intake is the appropriate starting point.