GLP-1 medications beyond weight loss: how far do the benefits extend?

GLP-1 receptor agonists began as diabetes drugs and became weight loss drugs. Since March 2024 the FDA has added approvals for cardiovascular risk reduction (semaglutide, March 2024), obstructive sleep apnea (tirzepatide, December 2024), chronic kidney disease in type 2 diabetes (semaglutide, January 2025), and MASH, the inflammatory form of fatty liver disease (semaglutide, August 2025) [1]. Trials are running in conditions further still from their origin. For each new indication, the question worth asking is how much of the benefit is explained by weight loss and blood sugar improvement, and how much is left over once those are accounted for.

Sorting the evidence that way produces three groups.

Mostly explained by weight loss

Sleep apnea. In the two SURMOUNT-OSA trials (469 adults with moderate to severe apnea and obesity, baseline apnea-hypopnea index about 50 events per hour), tirzepatide cut the index by 25 to 29 events per hour over 52 weeks, against 5 on placebo, while body weight fell 18 to 20 percent [2]. Weight loss by any method does something similar. In the Wisconsin Sleep Cohort, a 10 percent weight loss predicted a 26 percent fall in the index, and a 10 percent gain predicted a 32 percent rise [3]. The drug's effect on apnea is roughly what its weight loss would predict.

Fatty liver disease (MASH). In ESSENCE, 800 adults with MASH and moderate to advanced fibrosis received semaglutide 2.4 mg or placebo. At 72 weeks, steatohepatitis resolved without worsening fibrosis in 62.9 percent on semaglutide versus 34.3 percent on placebo, alongside weight loss of 10.5 percent versus 2.0 percent [4]. Weight loss on its own does much of this: in a 2015 lifestyle study of 293 patients with biopsy-proven NASH, 90 percent of those who lost 10 percent or more of their body weight had resolution of steatohepatitis [5]. Exploratory analyses of ESSENCE split the drug's liver effect roughly in half between weight-dependent and weight-independent parts, with the weight-independent share for MASH resolution estimated near 52 percent [6]. The authors flag that these mediation models rest on assumptions that cannot all be tested.

Heart failure with preserved ejection fraction. In STEP-HFpEF (529 patients with HFpEF and obesity), semaglutide improved the KCCQ symptom score by 7.8 points more than placebo and six-minute walk distance by 20.3 meters, with weight loss of 13.3 percent versus 2.6 percent [7]. A prespecified analysis found the gains scaled with weight lost: about 6.4 KCCQ points and 14.4 meters per 10 percent of body weight [8]. SUMMIT (731 patients) then tested tirzepatide against a hard endpoint and found a 38 percent lower rate of cardiovascular death or worsening heart failure (9.9 versus 15.3 percent, hazard ratio 0.62). The difference came from worsening heart failure events; cardiovascular deaths were few and did not differ [9]. Weight appears to be the main driver here, though the STEP-HFpEF investigators did not think it explained everything, and inflammation (CRP) fell as well.

Partly explained

Cardiovascular events. SELECT randomized 17,604 adults with established cardiovascular disease and overweight or obesity, but no diabetes, and found semaglutide cut major cardiovascular events by 20 percent over a mean follow-up of 39.8 months [10]. Two findings complicate a pure weight-loss story. The protection was similar across baseline HbA1c groups and regardless of how much HbA1c fell [11]. And weight loss at week 20 showed no relationship to later events, whereas reduction in waist circumference did; in the prespecified mediation analysis, waist reduction accounted for an estimated 33 percent of the benefit and weight loss for none [12]. A separate mediation analysis that modeled 12 risk factors together could explain about 31 percent of the effect in total [13]. The remaining share is unassigned. Inflammation and plaque biology are candidates; neither is proven.

Kidney disease. FLOW, the first dedicated kidney outcomes trial of a GLP-1 drug, enrolled 3,533 adults with type 2 diabetes and chronic kidney disease. Semaglutide cut the composite of kidney failure, sustained loss of kidney function, or kidney or cardiovascular death by 24 percent (hazard ratio 0.76) and slowed the yearly decline in filtration rate by 1.16 mL/min/1.73 m², with a weight difference of only about 4 kg between groups [14]. FLOW itself did not publish a mediation analysis. An exploratory analysis of two earlier semaglutide and liraglutide trials attributed about 25 percent of the kidney effect to HbA1c, with wide confidence intervals, and found no mediation by HbA1c in patients whose filtration rate was already below 60 [15].

Hard to explain by weight loss

Pressure inside the skull. Idiopathic intracranial hypertension is raised pressure around the brain, mostly in younger women with obesity, and it threatens vision. In a trial of 16 women with implanted telemetric pressure monitors (15 completed), exenatide lowered intracranial pressure by 5.7 cm of CSF at 2.5 hours after the first dose (p = 0.048) and by 6.4 cm at 24 hours; the 12-week reduction of 5.6 cm fell just short of conventional significance (p = 0.058) [16]. Weight cannot change on a 2.5-hour timescale. The proposed route is GLP-1 receptors in the choroid plexus, where the drug reduced cerebrospinal fluid secretion in rat studies [17]. One small trial is a signal, not a treatment; a phase 3 trial is the stated next step.

Alcohol use disorder. Four randomized trials have now tested GLP-1 drugs against drinking, with mixed results. A 2022 Danish trial of weekly exenatide in 127 treatment-seeking patients missed its primary endpoint of heavy drinking days, but found reduced drinking in the subgroup with obesity and, on brain imaging, quieter responses to alcohol cues in the ventral striatum [18]. A 2025 trial of low-dose semaglutide in 48 non-treatment-seeking adults over nine weeks reported fewer drinks per drinking day and lower craving; participants lost about 5 percent of body weight [19]. A 2026 trial of oral semaglutide in 50 adults over eight weeks missed its primary endpoint of laboratory-provoked craving but reported fewer heavy drinking days in weeks 5 to 8 [20]. The largest, SEMALCO, gave 108 treatment-seeking adults with obesity semaglutide 2.4 mg or placebo for 26 weeks on top of cognitive behavioral therapy; heavy drinking days fell 13.7 percentage points more on the drug [21]. The trials are small and short, and none was built to separate a reward effect from nausea and appetite suppression. That the clearest signals come from patients with obesity is a reason for caution about a weight-independent mechanism.

Limits of the evidence

The hard-endpoint results, in heart and kidney outcomes, come from trials of patients with established disease, diabetes, or obesity. Whether any of this extends to lean, metabolically healthy people taking these drugs for prevention has not been tested. Claims about Alzheimer's disease, cancer, or aging itself rest on observational data and trials still in progress.

Sources

1. U.S. Food and Drug Administration approvals: Wegovy (semaglutide) cardiovascular risk reduction, March 2024; Zepbound (tirzepatide) for obstructive sleep apnea, December 2024; Ozempic (semaglutide) for chronic kidney disease in type 2 diabetes, January 2025; Wegovy for noncirrhotic MASH with moderate to advanced fibrosis (accelerated approval), August 2025. Summarized in: BioSpace, "Wegovy cardiovascular approval furthers march into new indications" (2024); Pharmaphorum, "Ozempic is first GLP-1 drug FDA-approved for kidney disease" (2025); HCPLive, "FDA approves semaglutide (Wegovy) injection 2.4 mg for noncirrhotic MASH" (2025).
2. Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity. N Engl J Med. 2024;391:1193-1205. https://doi.org/10.1056/NEJMoa2404881
3. Peppard PE, Young T, Palta M, Dempsey J, Skatrud J. Longitudinal study of moderate weight change and sleep-disordered breathing. JAMA. 2000;284(23):3015-3021. PMID 11122588.
4. Sanyal AJ, Newsome PN, Kliers I, et al. Phase 3 trial of semaglutide in metabolic dysfunction-associated steatohepatitis (ESSENCE). N Engl J Med. 2025. https://doi.org/10.1056/NEJMoa2413258
5. Vilar-Gomez E, Martinez-Perez Y, Calzadilla-Bertot L, et al. Weight loss through lifestyle modification significantly reduces features of nonalcoholic steatohepatitis. Gastroenterology. 2015;149(2):367-378.e5. https://doi.org/10.1053/j.gastro.2015.04.005
6. Newsome PN, et al. Weight-dependent and -independent effects of semaglutide in participants with MASH: secondary analysis of the phase 3 ESSENCE trial. Abstracts presented at the European Congress on Obesity 2025 and AASLD The Liver Meeting 2025. Summary: EMJ Reviews, "Semaglutide improves MASH through weight-independent effects" (2025).
7. Kosiborod MN, Abildstrøm SZ, Borlaug BA, et al. Semaglutide in patients with heart failure with preserved ejection fraction and obesity (STEP-HFpEF). N Engl J Med. 2023;389(12):1069-1084. https://doi.org/10.1056/NEJMoa2306963
8. Butler J, Abildstrøm SZ, Borlaug BA, et al. Semaglutide in HFpEF across obesity class and by body weight reduction: a prespecified analysis of the STEP-HFpEF trial. Nat Med. 2023. https://doi.org/10.1038/s41591-023-02526-x
9. Packer M, Zile MR, Kramer CM, et al. Tirzepatide for heart failure with preserved ejection fraction and obesity (SUMMIT). N Engl J Med. 2025;392:427-437. https://doi.org/10.1056/NEJMoa2410027
10. Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). N Engl J Med. 2023;389(24):2221-2232. https://doi.org/10.1056/NEJMoa2307563
11. Lingvay I, Deanfield J, Kahn SE, et al. Semaglutide and cardiovascular outcomes by baseline HbA1c and change in HbA1c in people with overweight or obesity but without diabetes in SELECT. Diabetes Care. 2024;47(8):1360-1369. https://doi.org/10.2337/dc24-0764
12. Deanfield J, et al. Semaglutide and cardiovascular outcomes by baseline and changes in adiposity measurements: a prespecified analysis of the SELECT trial. Lancet. 2025;406:2257-2268. https://doi.org/10.1016/S0140-6736(25)01375-3
13. Colhoun HM, et al. Mediation analysis of the cardiovascular effect of semaglutide in SELECT. Eur Heart J. 2026. Summary: Healio, "CV benefits of semaglutide appear to be related to more than weight loss" (October 2026).
14. Perkovic V, Tuttle KR, Rossing P, et al. Effects of semaglutide on chronic kidney disease in patients with type 2 diabetes (FLOW). N Engl J Med. 2024;391(2):109-121. https://doi.org/10.1056/NEJMoa2403347
15. Mann JFE, Buse JB, Idorn T, et al. Potential kidney protection with liraglutide and semaglutide: exploratory mediation analysis. Diabetes Obes Metab. 2021;23(9):2058-2066. https://doi.org/10.1111/dom.14443
16. Mitchell JL, Lyons HS, Walker JK, et al. The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: a randomized clinical trial. Brain. 2023;146(5):1821-1830. https://doi.org/10.1093/brain/awad003
17. Botfield HF, Uldall MS, Westgate CSJ, et al. A glucagon-like peptide-1 receptor agonist reduces intracranial pressure in a rat model of hydrocephalus. Sci Transl Med. 2017;9(404):eaan0972. https://doi.org/10.1126/scitranslmed.aan0972
18. Klausen MK, Jensen ME, Møller M, et al. Exenatide once weekly for alcohol use disorder investigated in a randomized, placebo-controlled clinical trial. JCI Insight. 2022;7(19):e159863. https://insight.jci.org/articles/view/159863
19. Hendershot CS, Bremmer MP, Paladino MB, et al. Once-weekly semaglutide in adults with alcohol use disorder: a randomized clinical trial. JAMA Psychiatry. 2025. https://doi.org/10.1001/jamapsychiatry.2024.4789
20. Schacht JP, Sakai JT, Raymond K, Shelton R. Oral semaglutide for alcohol use disorder: a randomized clinical trial. Am J Psychiatry. Published online July 29, 2026. https://doi.org/10.1176/appi.ajp.20260003
21. Klausen MK, et al. Once-weekly semaglutide versus placebo in patients with alcohol use disorder and comorbid obesity (SEMALCO): a randomised, double-blind, placebo-controlled trial. Lancet. 2026;407(10540):1687-1698. https://doi.org/10.1016/S0140-6736(26)00305-3