Which Weight Loss Drugs Work Best Over 4 Years? Real-World Veteran Data

Semaglutide and phentermine/topiramate showed the most consistent long-term weight loss over up to 48 months in a real-world veteran population.

Rodriguez, Allison D et al.·Federal practitioner : for the health care professionals of the VA·2024·Moderate Evidencecohort
RPEP-09162CohortModerate Evidence2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
cohort
Evidence
Moderate Evidence
Sample
U.S. veterans prescribed weight loss medications at Veteran Health Indiana
Participants
U.S. veterans prescribed weight loss medications at Veteran Health Indiana

What This Study Found

Semaglutide and phentermine/topiramate showed the most consistent long-term weight loss among veterans, with data extending up to 48 months.

Key Numbers

Weight tracked at 3, 6, 12, 24, 36, and 48 months. Six medications compared: semaglutide, orlistat, liraglutide, phentermine, phentermine/topiramate, and naltrexone/bupropion.

How They Did This

Single-center retrospective study analyzing weight outcomes at multiple timepoints for veterans prescribed various weight loss medications.

Why This Research Matters

Most weight loss drug studies last 1-2 years. This study provides real-world data on how well these medications work over up to 4 years, which matters because obesity is a chronic condition.

The Bigger Picture

Most weight loss drug studies last 1–2 years. This 4-year real-world data fills an important gap, showing which medications maintain their effect over the timeframe that actually matters for chronic disease management.

What This Study Doesn't Tell Us

Retrospective single-center study without randomization. Patients were not randomly assigned to medications, so differences between groups may reflect patient selection.

Questions This Raises

  • ?Why does phentermine/topiramate perform as well as semaglutide long-term?
  • ?Would tirzepatide perform even better over 4 years?

Trust & Context

Key Stat:
Up to 48 months of data One of the longest real-world comparisons of weight loss medications, tracking outcomes for up to 4 years
Evidence Grade:
Rated moderate: long follow-up period provides valuable real-world data, but retrospective single-center design with no randomization limits causal conclusions.
Study Age:
Published in 2024. Builds on a 2021 study from the same center with extended follow-up.
Original Title:
Long-Term Assessment of Weight Loss Medications in a Veteran Population.
Published In:
Federal practitioner : for the health care professionals of the VA, DoD, and PHS, 41(7), 202-207 (2024)
Database ID:
RPEP-09162

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Which weight loss drug works longest?

In this 4-year real-world study, semaglutide and phentermine/topiramate showed the most sustained results over time.

Do weight loss drugs stop working over time?

Some do — this study found differences between medications in long-term effectiveness, with semaglutide and phentermine/topiramate maintaining benefits best.

Read More on RethinkPeptides

Cite This Study

RPEP-09162·https://rethinkpeptides.com/research/RPEP-09162

APA

Rodriguez, Allison D; Ifeachor, Amanda P; Moore, Emily A; Otte, Cassandra F; Schopper, M Joseph; Liangpunsakul, Suthat; Lteif, Amale A. (2024). Long-Term Assessment of Weight Loss Medications in a Veteran Population.. Federal practitioner : for the health care professionals of the VA, DoD, and PHS, 41(7), 202-207. https://doi.org/10.12788/fp.0490

MLA

Rodriguez, Allison D, et al. "Long-Term Assessment of Weight Loss Medications in a Veteran Population.." Federal practitioner : for the health care professionals of the VA, 2024. https://doi.org/10.12788/fp.0490

RethinkPeptides

RethinkPeptides Research Database. "Long-Term Assessment of Weight Loss Medications in a Veteran..." RPEP-09162. Retrieved from https://rethinkpeptides.com/research/rodriguez-2024-longterm-assessment-of-weight

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.