Semaglutide and phentermine/topiramate showed the most consistent long-term weight loss over up to 48 months in a real-world veteran population.
Up to 48 months of dataOne of the longest real-world comparisons of weight loss medications, tracking outcomes for up to 4 years
What the researchers found
Semaglutide and phentermine/topiramate showed the most consistent long-term weight loss among veterans, with data extending up to 48 months.
Why it 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 numbers in context
Weight tracked at 3, 6, 12, 24, 36, and 48 months. Six medications compared: semaglutide, orlistat, liraglutide, phentermine, phentermine/topiramate, and naltrexone/bupropion.
How the study worked
Single-center retrospective study analyzing weight outcomes at multiple timepoints for veterans prescribed various weight loss medications.
Who was studied
U.S. veterans prescribed weight loss medications at Veteran Health Indiana
What this study cannot tell us
Retrospective single-center study without randomization. Patients were not randomly assigned to medications, so differences between groups may reflect patient selection.
How to read the evidence
Rated moderate: long follow-up period provides valuable real-world data, but retrospective single-center design with no randomization limits causal conclusions.
When this study was published
Published in 2024. Builds on a 2021 study from the same center with extended follow-up.
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.
Questions still open
- Why does phentermine/topiramate perform as well as semaglutide long-term?
- Would tirzepatide perform even better over 4 years?
Common questions
Which weight loss drug works longest?
Do weight loss drugs stop working over time?
Read the original research
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
Citation
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