Comparison
A comparison of the two major GLP-1/GIP-era weight-loss drugs and how their evidence differs from compounded or research-market claims.
Both have approved products; the useful comparison is efficacy, tolerability, approved labeling, and where compounded or off-label marketing changes the conversation.
Both medicines have large randomized human programs and regulator-reviewed prescribing information. That makes it possible to compare defined products, populations, endpoints, adverse effects, and dose-escalation schedules instead of relying on mechanism or anecdotes.
Both have approved products for chronic weight management in specified adults. Their other approved indications and warnings are product-specific, so the current prescribing information matters more than a general GLP-1 or GIP label.
A compounded product is not the FDA-approved finished medicine. Concentration, excipients, device, storage, and dosing instructions can differ, and FDA does not review compounded drugs for safety, effectiveness, or quality before they are marketed.
| Dimension | Semaglutide | Tirzepatide |
|---|---|---|
| Overall evidence grade | A | A |
| Evidence label | Strong human evidence | Strong human evidence |
| Regulatory status | Approved for specific use | Approved for specific use |
| Editorial confidence | Moderate confidence | Moderate confidence |
| Efficacy | 5/5 strong | 5/5 strong |
| Safety | 4/5 substantial | 4/5 substantial |
| Regulatory risk | 1/5 low | 1/5 low |
| Product quality risk | 1/5 low | 1/5 low |
| Primary claim categories | Weight management, Type 2 diabetes, FDA-approved product comparison | Weight management, Type 2 diabetes, OSA with obesity, FDA-approved product comparison |
Semaglutide has FDA-approved product labels for specific uses; compounded, salt-form, and online-market claims need separate quality and dosing-risk review.
Tirzepatide has FDA-approved product labels for specific uses; compounded, clinic, gray-market, or off-label marketing claims need separate support.
Accessed 2026-06-08.
FDA distinguishes approved semaglutide products from compounded semaglutide products and describes dosing-error concerns.
FDA. FDA Approves New Medication for Chronic Weight Management 2023.
Accessed 2026-06-08.
FDA approval announcement for Zepbound, a tirzepatide product for chronic weight management in specified adults.
FDA. Compounding and the FDA: Questions and Answers 2026.
Accessed 2026-06-08.
FDA explains that compounded drugs are not FDA-approved and that FDA does not verify their safety, effectiveness, or quality before marketing.