Impact of pharmacist-managed weight management service on weight loss and associated clinical outcomes
Authors: Rita Chen, PharmD; Kelly Goldberg, PharmD, BCACP; Emmanuel Kim, PharmD; Jessie Morgan, PharmD, MSHA, BCPS; Kristen Fink, PharmD, BCPS, BCACP, CDCES
Background/Objective: The purpose of this study is to evaluate the impact of a pharmacist-managed weight management service (WMS) on weight loss and related clinical outcomes in patients newly initiated on GLP-1 receptor agonist (RA) or GIP/GLP-1 RA therapy.
Methods: This retrospective cohort study evaluated adults enrolled in a pharmacy WMS within Kaiser Permanente Mid-Atlantic States between June 1, 2024 to May 31, 2025. Eligible patients were ≥18 years of age and newly initiated on a GLP-1 RA or GIP/GLP-1 RA through WMS. Patients <18 years of age, pregnant or breastfeeding, using compounded GLP-1 RA or GIP/GLP-1 RA, previously initiated on GLP-1 RA or GIP/GLP-1 RA therapy prior to enrollment, or paying cash for therapy were excluded. Of 6,968 enrolled patients, 127 WMS patients and 127 usual care patients were randomly selected. Primary outcomes were percent change in body weight from baseline to program completion and percent change in body mass index (BMI). Secondary outcomes included changes in blood pressure, HbA1c, and lipids; pharmacist intervention; medication adherence (proportion of days covered); enrollment duration; and adverse events. Baseline characteristics were summarized descriptively, and independent t-tests compared outcomes (α=0.05).
Results: Mean weight change was 8.07% with pharmacist-managed care versus 4.23% in usual care (p<0.001), with BMI reduction of 2.80 vs 0.27 kg/m² (p=0.045). A higher proportion of control group patients achieved ≥5% weight loss (36.2% vs 33.9%), likely due to tirzepatide use versus semaglutide in WMS. WMS patients experienced greater cardiometabolic improvements, with 88% showing blood pressure reductions compared with 71.2% in controls, and 75% of diabetic patients demonstrating HbA1c improvement versus 53.8%. Pharmacist interventions included dose titration, adverse effect management, and lifestyle counseling. Adverse events were primarily gastrointestinal. PDC not calculated due to monthly GLP-1 RA or GIP/GLP-1 RA titration and insufficient refill history.
Conclusion: Pharmacist-managed weight management services were associated with greater weight reduction and favorable cardiometabolic outcomes among adults initiating GLP-1 RA or GIP/GLP-1 RA therapy compared with usual care. These findings highlight the value of pharmacist-led weight management programs in supporting medication optimization, adherence, and multidisciplinary obesity care.
Learning Objective: Describe the impact of a pharmacist-managed weight management service on weight loss and associated clinical outcomes in adults newly initiated on GLP-1 RA or GIP/GLP-1 RA therapy.
Self-Assessment Question: True or False: Pharmacists can support patients taking GLP-1 RA or GIP/GLP-1 RA medications by managing dosing, monitoring for adverse effects, and providing lifestyle counseling.
