Weight-management evidence

What human evidence and regulatory status actually support.

This section separates approved medicines from drugs that are still in trials, candidates that failed in development and research-market vials. It uses direct comparisons where they exist and describes trial doses as study methods, not patient instructions.

Source-based editorial review; independent clinical review pending. Read the sources.

Evidence by peptide

• AOD-9604: AOD-9604 is a fragment of human growth hormone that was studied as an obesity drug. In FDA's review, the largest 24-week oral trial did not produce statistically significant weight loss compared with placebo. The agency has not approved AOD-9604 for any use. [1]
• Semaglutide: Semaglutide is the active ingredient in several FDA-approved prescription products. Each has its own indication, strength, route and instructions. On March 19, 2026, FDA approved a 7.2 mg once-weekly dose of Wegovy HD for eligible adults with obesity. This does not make a compounded preparation interchangeable with any of the branded products. [1–3]
• Tirzepatide: Tirzepatide is the active ingredient in the FDA-approved products Mounjaro and Zepbound. SURMOUNT-5 directly compared maximum tolerated doses in adults with obesity who did not have diabetes. Average weight loss at 72 weeks was 20.2% with tirzepatide and 13.7% with semaglutide. The older 22.5% and 15% figures came from separate trials and should not be used as a head-to-head comparison. [1,2]
• Retatrutide: Retatrutide is an investigational drug that acts at the GIP, GLP-1 and glucagon receptors. Lilly announced topline Phase 3 results from TRIUMPH-1 in May 2026. At 80 weeks, average weight loss in the 12 mg arm was 28.3% under the efficacy estimand and 25.0% under the treatment-regimen estimand, compared with 2.2% and 3.9% for placebo. The full results have not yet appeared in a peer-reviewed publication. [1,2]
• Survodutide: Survodutide is still being studied and is not an approved treatment. In SYNCHRONIZE-1, researchers tested 3.6 mg and 6.0 mg once weekly. The 4.8 mg figure comes from an earlier Phase 2 trial. At week 76, mean weight change under the treatment-regimen estimand was a 12.2% decrease and a 13.0% decrease, compared with a 5.4% decrease for placebo. [1,2]

Common Questions

• Does this page recommend a dose or stack?

  No. Trial protocols describe research, and approved-product instructions apply only to the named formulation and labeled population.

• Can animal, cell or mechanistic findings prove a human benefit?

  No. They can justify further research but cannot be rewritten as a demonstrated outcome in people.

Sources and study limits

1. Pharmacy Compounding Advisory Committee briefing: AOD-9604 U.S. Food and Drug Administration (2024)
2. FDA Approves Higher Dose Semaglutide (Wegovy HD) U.S. Food and Drug Administration (2026)
3. Wegovy and Wegovy HD prescribing information U.S. Food and Drug Administration (2026)
4. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss U.S. Food and Drug Administration (2026)
5. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity Jastreboff AM, et al. (2025)
6. Zepbound prescribing information U.S. Food and Drug Administration
7. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss U.S. Food and Drug Administration (2026)
8. Lilly’s triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial Eli Lilly and Company (2026)
9. TRIUMPH-1: A Study of Retatrutide in Participants With Obesity or Overweight (NCT05929066) ClinicalTrials.gov (2026)
10. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss U.S. Food and Drug Administration (2026)
11. Once-Weekly Survodutide in Adults with Obesity le Roux CW, et al. (2026)
12. Once-weekly survodutide in people with obesity: a randomised, double-blind, placebo-controlled, dose-finding phase 2 trial Blüher M, et al. (2024)
13. SYNCHRONIZE-1 (NCT06066515) ClinicalTrials.gov

Related Comparisons

• AOD-9604 vs Semaglutide: An unapproved fragment with a negative development program versus approved, product-specific semaglutide medicines.
• Ozempic vs Wegovy: The same active ingredient does not make two approved products interchangeable.
• Pen vs Vial: Container type is not a shortcut for approval, quality, concentration or legal status.
• Semaglutide vs Retatrutide: Approved, product-specific semaglutide versus an investigational triple agonist.
• Semaglutide vs Tirzepatide: Two approved drug families compared directly in SURMOUNT-5.
• Tesamorelin vs Semaglutide: Different medicines, indications and product instructions.
• Tirzepatide vs Retatrutide: An approved dual agonist versus an investigational triple agonist.

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Educational evidence summary. FDA approval, investigational status, and compounding are separate categories. Use the current label and a licensed clinician for patient-specific decisions.

vialprep research · Sources: PubMed, FDA, peer-reviewed trials · How we verify