Use case

Weight loss

Which peptide drugs have the strongest human evidence for weight loss?

Context

Weight-loss claims change depending on what is actually being used: an approved medicine, a compounded version, or a research-use product.

Compare semaglutide and tirzepatide for weight loss, including approved-drug evidence, compounded-product issues, and research-use claims.

Peptides compared

Strong human evidence

Semaglutide

The active ingredient behind Ozempic, Wegovy, and Rybelsus, useful for separating product-specific label evidence from compounded or research-use claims.

Approved for specific use

Strong human evidence

Tirzepatide

The active ingredient in Mounjaro and Zepbound, with strong product-specific evidence for type 2 diabetes, chronic weight management, and OSA in adults with obesity.

Approved for specific use

Sources

1.
FDA. FDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products 2024.
Accessed 2026-06-08.
FDA distinguishes approved semaglutide products from compounded semaglutide products and describes dosing-error concerns.
2.
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.
3.
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.